0001822479-24-000011 | 10-K | XBRL Viewer

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Goodwill and Other Intangible Assets - Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2024	$ 80,187
2025	42,735
2026	22,514
2027	21,438
2028	20,890
Thereafter	124,024
Total	$ 311,788

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies We depend on a limited number of suppliers and our agreements with these suppliers account for material portions of our supply and direct material costs. These costs include obligations under various supply agreements in our Nordion segment for Co-60 that are enforceable and legally binding on us. As of December 31, 2023, we had minimum purchase commitments primarily with domestic and international suppliers of raw materials for the Nordion business totaling $1,607.1 million. The terms of these long-term supply or service arrangements range from 1 to 40 years. In addition, our Sterigenics segment has obligations to purchase ethylene oxide (“EO”). Our contract to purchase EO in the U.S. requires us to purchase all of our requirements from one supplier, and our contracts to purchase EO outside the U.S. generally require that we purchase a specified percentage of our requirements for our operations in the countries covered by those contracts. We expect to utilize the Co-60 and EO encompassed by these agreements in the normal course of our business and therefore our commitments under these agreements are not recognized on the consolidated balance sheets as a liability. From time to time, we may be subject to various lawsuits and other claims, as well as gain contingencies, in the ordinary course of our business. In addition, from time to time, we receive communications from government or regulatory agencies concerning investigations or allegations of noncompliance with laws or regulations in jurisdictions in which we operate. We assess these regulatory and legal actions to determine if a contingent liability should be recorded. In making these determinations, we may, depending on the nature of the matter, consult with internal and external legal counsel and technical experts. We establish reserves for specific liabilities in connection with regulatory and legal actions that we determine to be both probable and reasonably estimable. The outcomes of regulatory and legal actions can be difficult to predict and are often resolved over long periods of time, making our probability and estimability determinations highly judgmental. Probability determinations require the analysis of various possible outcomes, assessments of potential damages and the impact of multiple factors beyond our control, including potential actions by others, interpretations of the law, and changes and developments in relevant facts, circumstances, regulations and other laws. If a potentially material loss contingency is not probable, but is reasonably possible, or is probable but cannot be estimated, then the nature of the contingent liability is disclosed, together with an estimate of the range of possible loss if the range is determinable and material. In certain of the matters described below, we are not able to estimate potential liability because of the uncertainties related to the outcome(s) and/or the amount(s) or range(s) of loss. The ultimate resolution of pending regulatory and legal matters in future periods, including the matters described below, may have a material adverse effect on our financial condition, results of operations and/or liquidity. The Company may also incur material defense and settlement costs, diversion of management resources and other adverse effects on our business, financial condition, and/or results of operations. Ethylene Oxide Tort Litigation Sterigenics U.S., LLC (“Sterigenics”) and other medical supply sterilization companies have been subjected to tort lawsuits alleging various injuries caused by low-level environmental exposure to EO used at or emitted from sterilization facilities. Those lawsuits, as detailed further below, are individual claims, as opposed to class actions. Illinois Subsidiaries of the Company and other parties are defendants in lawsuits in Illinois in which plaintiffs allege personal injuries and wrongful death resulting from purported use, emissions and releases of EO from or at Sterigenics’ former Willowbrook facility and seek damages and other forms of relief (the “Willowbrook Cases”). In 2022, there were jury trials in two Willowbrook Cases. The first trial resulted in a September 2022 verdict against Sterigenics and Sotera Health LLC (the “Defendant Subsidiaries”) in the amount of $358.7 million, including $320.0 million in punitive damages. The second trial resulted in a November 2022 verdict in favor of the Defendant Subsidiaries on all counts. On January 9, 2023, the Defendant Subsidiaries announced a settlement that, subject to various conditions, would resolve the then-pending or threatened 880+ Willowbrook Cases for $408.0 million, including the two cases in which there were jury trials during 2022 (“the Willowbrook Settlement”). Based on our assessment of the likelihood that the conditions to the Willowbrook term sheets would be satisfied or waived, the Company recorded a charge of $408.0 million for the year ended December 31, 2022. On June 23, 2023, the Circuit Court of Cook County entered an order confirming that the Willowbrook Settlement was a good-faith settlement under the Illinois Contribution Among Joint Tortfeasors Act. On July 6, 2023, the settled claims were dismissed with prejudice, with the Circuit Court of Cook County retaining jurisdiction to adjudicate disputes over liens on settlement proceeds to be paid to settling plaintiffs and to oversee the administration of the settlements of wrongful death cases. Two claimants eligible to participate in the Willowbrook Settlement declined to participate and their cases remain pending in the Circuit Court of Cook County (each an “Opt-Out Case”). 23 personal injury lawsuits have been filed in the Circuit Court of Cook County since eligibility to participate in the Willowbrook Settlement closed in March 2023 (“Post-Settlement Willowbrook Cases”). Three Post-Settlement Willowbrook Cases have been removed to the United States District Court for the Northern District of Illinois. The remaining Post-Settlement Willowbrook Cases will proceed in the Circuit Court of Cook County and are expected to be consolidated for discovery and pretrial purposes only. We intend to vigorously defend the Opt-Out Cases and Post-Settlement Willowbrook Cases. Georgia The Defendant Subsidiaries and other parties are defendants in lawsuits in Georgia in which plaintiffs allege personal injuries, wrongful death and property devaluation resulting from use, emissions and releases of EO from or at Sterigenics’ Atlanta facility and seek damages and, in certain cases, other forms of relief (the “Atlanta Cases”). In October 2023, the Defendant Subsidiaries agreed to pay $35.0 million to settle 79 of the Atlanta Cases, including a personal injury case that was scheduled to begin trial in the State Court of Gwinnett County that month, and 78 other cases being pursued by the same Plaintiff’s counsel in the personal injury case that was scheduled to begin trial in October 2023 (the “Atlanta Settlement”). The Atlanta Settlement was completed in January 2024, with the settling plaintiffs agreeing to file the necessary dismissals and, where required, motions for court approval. Approximately 245 personal injury and wrongful death claims remain pending in the State Court of Cobb County and have been consolidated for pretrial purposes (the “Consolidated Personal Injury Cases”). The Consolidated Personal Injury Cases are proceeding under a case management order pursuant to which a “pool” of eight cases will proceed to judicial determination of general causation issues in Phase 1 and specific causation issues in Phase 2; the first trial of any “pool” case that survives Phases 1 and 2 is not expected to begin before September 2025. The remaining Consolidated Personal Injury Cases (including nine cases that include both personal injury and property claims) are stayed. Two additional personal injury lawsuits pending in Cobb County have not been consolidated. The parties have jointly asked the court to stay one of these cases along with the stayed cases in the Consolidated Personal Injury Cases. In the other case, employees of a sterilization customer of Sterigenics allege they were injured by exposure while working at the customer’s distribution facility to residual EO allegedly emanating from products of the customer that had been sterilized at Sterigenics’ Atlanta facility; discovery is underway and, pursuant to the customer’s contract with Sterigenics, the customer is indemnifying Sterigenics against this lawsuit. The Defendant Subsidiaries are also defendants in approximately 365 property devaluation lawsuits that remain pending in the State Court of Cobb County and have been consolidated for pretrial purposes (the “Consolidated Property Cases”). Ten of the Consolidated Property Cases are proceeding under case management orders while the remaining cases are stayed. Discovery in five of the cases is underway; dispositive motions remain pending in the other five. We intend to vigorously defend the remaining Atlanta Cases. New Mexico The Company and certain subsidiaries are defendants in a lawsuit in the Third Judicial District Court, Doña Ana County, New Mexico in which the New Mexico Attorney General ( “NMAG”) alleges that emissions and releases of EO from Sterigenics’ facility in Santa Teresa, New Mexico have deteriorated the air quality in Santa Teresa and surrounding communities and materially contributed to increased health risks suffered by residents of those communities. The Complaint asserted claims for public nuisance, negligence, strict liability, violations of New Mexico’s Public Nuisance Statute and Unfair Practices Act and sought various forms of relief, including injunctive relief and damages. In June 2021, the Court entered an Order Granting Preliminary Injunction prohibiting Sterigenics from allowing any uncontrolled emissions or releases of EO from the Santa Teresa facility. In December 2021, the Court entered an order establishing a protocol to monitor Sterigenics’ compliance with the preliminary injunction. Operations at the facility continue to comply with the June 2021 and December 2021 orders. In August 2023, the Court granted Sterigenics’ motion for summary judgment on strict liability, the Unfair Practices Act claim, and the NMAG’s claims for decreased property values, increased healthcare costs and medical monitoring costs, and instructed the NMAG to amend its Complaint in compliance with the order and to exclude any claim for injunctive relief (the “Summary Judgment Order”). In August 2023, the NMAG sought reconsideration of the Summary Judgment Order, which was denied in December 2023. While this motion was pending, the NMAG filed an Amended Complaint. The NMAG is seeking leave to file an interlocutory appeal of the Summary Judgment Order which, if granted, would stay all proceedings in the underlying case during the appeal. In January 2024, Sterigenics filed motions to dissolve the June 2021 injunction and to dismiss the Amended Complaint. A defense motion challenging the Court’s jurisdiction over Sotera Health Company and another defendant also remains pending. The Company, Sterigenics and certain other subsidiaries are also defendants in a lawsuit pending in the United States District Court for the District of New Mexico alleging wrongful death resulting from purported exposure to EO used, emitted and released from Sterigenics’ facility in Santa Teresa, New Mexico while the decedent was working at a different company’s facility approximately one mile away. The court has not yet entered a case management order. We intend to defend this lawsuit vigorously. * * * Additional EO tort lawsuits may be filed in the future against the Company and/or its subsidiaries relating to Sterigenics’ Willowbrook, Atlanta, Santa Teresa or other EO facilities. Based on our view of the strength of the science and related evidence that emissions of EO from Sterigenics’ operations have not caused and could not have caused the harms alleged in such lawsuits, we believe that losses in the remaining or future EO cases are not probable. Although the Company intends to defend itself vigorously on the merits, future settlements of EO tort lawsuits are reasonably possible. The Willowbrook and Atlanta Settlements were driven by dynamics unique to the cases that were settled and thus should not give rise to presumptions that the Company will settle additional EO tort lawsuits and/or that any such settlements will be for comparable amounts. Potential trial and settlement outcomes can vary widely based a host of factors. EO tort lawsuits will be presided over by different judges, tried by different counsel presenting different evidence and decided by different juries. The substantive and procedural laws of jurisdictions vary and can meaningfully impact the litigation process and outcome of a case. Each plaintiff’s claim involves unique facts and evidence including the circumstances of the plaintiff’s alleged exposure, the type and severity of the plaintiff’s disease, the plaintiff’s medical history and course of treatment, the location of and other factors related to the plaintiff’s real property, and other circumstances. The outcomes of trials before juries are rarely certain and a judgment rendered or settlement reached in one case is not necessarily representative of potential outcomes of other seemingly comparable cases. As a result, it is not possible to estimate a reasonably possible loss or range of loss with respect to any future EO tort lawsuit, trial or settlement. Insurance Coverage for Environmental Liabilities An environmental liability insurance policy under which we have received coverage for the EO tort lawsuits in Illinois, Georgia and New Mexico described above had limits of $10.0 million per occurrence and $20.0 million in the aggregate. Those per occurrence and aggregate limits were fully utilized in the defense of the Illinois, Georgia and New Mexico litigation. Our insurance for future alleged environmental liabilities excludes coverage for EO claims. We are pursuing additional insurance coverage for our legal expenses related to EO tort lawsuits like the Illinois, Georgia and New Mexico matters described above. In 2021, Sterigenics filed an insurance coverage lawsuit in the U.S. District Court for the Northern District of Illinois relating to two commercial general liability policies issued in the 1980s (the “Northern District of Illinois Coverage Lawsuit”). The court has issued an order declaring that the defendant insurer owes Sterigenics and another insured party a duty to defend the Willowbrook Cases (the “Duty to Defend Order”) and entered judgment for Sterigenics in January 2024 in the amount of $110.2 million for certain defense costs incurred in the Willowbrook Cases as of August 2022 (the “Defense Costs Judgment”). The defendant insurer has appealed the Duty to Defend Order and Defense Costs Judgment. Sterigenics is also a party in insurance coverage lawsuits pending in the Circuit Court of Cook County, Illinois and the Delaware Superior Court relating to insurance coverage from various historical commercial general liability policies for certain EO litigation settlement amounts and defense costs that the insurer in the Northern District of Illinois Coverage Lawsuit may fail to fund. It is not possible to predict how much, if any, of the insurance proceeds sought will ultimately be recovered. Sotera Health Company Securities Litigation & Related Matters In January 2023, a stockholder class action was filed in the U.S. District Court for the Northern District of Ohio against the Company, certain past and present directors and senior executives, the Company’s private equity stockholders and the underwriters of the Company’s initial public offering (“IPO”) in November 2020 and the Company’s secondary public offering (“SPO”) in March 2021 (the “Michigan Funds Litigation”). In April 2023, the court appointed the Oakland County Employees’ Retirement System, Oakland County Voluntary Employees’ Beneficiary Association, and Wayne County Employees’ Retirement System (the “Michigan Funds”) to serve as lead plaintiff to prosecute claims on behalf of a proposed class of stockholders who acquired shares of the Company in connection with our IPO or SPO or between November 20, 2020 and September 19, 2022 (the “Proposed Class”). The Michigan Funds allege that statements made regarding the safety of the Company’s use of EO and/or its EO tort lawsuits and other risks of its EO operations violated Sections 11, 12(a)(2) and 15 of the Securities Act of 1933 (when made in the registration statements for the IPO and SPO) and Sections 10(b), Section 20(a) and Rule 10b-5 of the Securities Exchange Act of 1934 (when made in subsequent securities filings and other contexts). Defendants have moved to dismiss the Amended Complaint and that motion remains pending. In May 2023 and July 2023, the Company received demands pursuant to 8 Del. C. §220 for inspections of its books and records from shareholders purporting to be investigating the Company’s internal operations, disclosure practices and other matters alleged and at issue in the Michigan Funds Litigation (the “220 Demands”). The Company is producing documents in response to the 220 Demands. The Company believes that the allegations and claims in the Michigan Funds Litigation and 220 Demands are without merit and plans to vigorously defend the Michigan Funds Litigation.

Revenue Recognition

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Revenue Recognition

The following table shows disaggregated net revenues from contracts with external customers by timing of revenue and by segment for the years ended December 31, 2023, 2022 and 2021:


	Year Ended December 31, 2023
	Sterigenics		Nordion		Nelson Labs		Consolidated
Point in time	$	667,130	$	153,747	$	—	$	820,877
Over time	—		6,712		221,699		228,411
Total	$	667,130	$	160,459	$	221,699	$	1,049,288


	Year Ended December 31, 2022
	Sterigenics		Nordion		Nelson Labs		Consolidated
Point in time	$	626,646	$	147,499	$	—	$	774,145
Over time	—		6,140		223,402		229,542
Total	$	626,646	$	153,639	$	223,402	$	1,003,687


	Year Ended December 31, 2021
	Sterigenics		Nordion		Nelson Labs		Consolidated
Point in time	$	571,829	$	139,135	$	—	$	710,964
Over time	—		1,372		219,142		220,514
Total	$	571,829	$	140,507	$	219,142	$	931,478

When we receive consideration from a customer prior to transferring goods or services under the terms of a sales contract, we record deferred revenue, which represents a contract liability. Deferred revenue totaled $13.5 million and $12.1 million at December 31, 2023 and 2022, respectively. We recognize deferred revenue after we have transferred control of the goods or services to the customer and all revenue recognition criteria are met.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

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+ Details

Property, Plant and Equipment - Schedule (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,451,691	$ 1,213,423
Less accumulated depreciation	(504,777)	(438,896)
Property, plant and equipment, net	946,914	774,527
Land and buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	345,309	317,930
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	82,582	67,386
Machinery, equipment, including Co-60
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	710,000	577,670
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,754	7,747
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	51,437	44,796
Asset retirement costs
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	6,590	4,255
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 247,019	$ 193,639

Cover - USD ($)	12 Months Ended
Cover - USD ($)	Dec. 31, 2023	Feb. 20, 2024	Jun. 30, 2023
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-39729
Entity Registrant Name	SOTERA HEALTH COMPANY
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-3531161
Entity Address, Address Line One	9100 South Hills Blvd
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Broadview Heights
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44147
City Area Code	440
Local Phone Number	262-1410
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	SHC
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 1,871,267,118
Entity Common Stock, Shares Outstanding		282,832,200
Documents Incorporated by Reference	Portions of the Definitive Proxy Statement for the registrant’s 2024 Annual Meeting of Stockholders are incorporated by reference in Part III of this Annual Report on Form 10-K. The proxy statement will be filed with the Securities and Exchange Commission within 120 days after the end of the registrant’s fiscal year ended December 31, 2023.
Entity Central Index Key	0001822479
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Amendment Flag	false

Share-Based Compensation - Pre-IPO Awards (Class B-1 and B-2) (Details) - Restricted Stock - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pre-IPO B-1
Number of Shares
Beginning balance (in shares)	716,091	1,206,089	2,201,239
Forfeited (in shares)	(16,243)	(54,333)	(72,467)
Vested (in shares)	(347,401)	(435,665)	(922,683)
Ending balance (in shares)	352,447	716,091	1,206,089
Pre-IPO B-2
Number of Shares
Beginning balance (in shares)	1,098,415	2,023,959	2,323,333
Forfeited (in shares)	(111,304)	(925,544)	(299,374)
Vested (in shares)	0	0	0
Ending balance (in shares)	987,111	1,098,415	2,023,959

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

Long-term debt consisted of the following:


(thousands of U.S. dollars)
As of December 31, 2023	Gross Amount		Unamortized Debt Issuance Costs		Unamortized Debt Discount		Net Amount
Term loan, due 2026	1,763,100		(1,606)		(10,298)		1,751,196
Term loan B, due 2026	497,500		(7,616)		(12,609)		477,275
	2,260,600		(9,222)		(22,907)		2,228,471
Less current portion	5,000		(76)		(127)		4,797
Long-term debt	$	2,255,600	$	(9,146)	$	(22,780)	$	2,223,674


(thousands of U.S. dollars)
As of December 31, 2022	Gross Amount		Unamortized Debt Issuance Costs		Unamortized Debt Discount		Net Amount
Term loan, due 2026	1,763,100		(2,140)		(13,845)		1,747,115
Revolving credit facility	200,000		(3,328)		—		196,672
Other long-term debt	450		(3)		—		447
	1,963,550		(5,471)		(13,845)		1,944,234
Less current portion	200,450		(3,331)		—		197,119
Long-term debt	$	1,763,100	$	(2,140)	$	(13,845)	$	1,747,115

Schedule of Maturities of Long-term Debt

Aggregate maturities of the Company’s long-term debt, excluding debt discounts, as of December 31, 2023, are as follows:


(thousands of U.S. dollars)
2024	$	5,000
2025	5,000
2026	2,250,600


Thereafter	—
Total	$	2,260,600

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

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+ Details

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid taxes	$ 4,129	$ 26,598
Prepaid business insurance	7,174	9,964
Prepaid rent	1,150	998
Customer contract assets	17,785	19,777
Insurance and indemnification receivables	0	3,724
Current deposits	715	660
Prepaid maintenance contracts	422	324
Value added tax receivable	4,306	1,640
Prepaid software licensing	2,503	1,832
Stock supplies	3,669	3,656
Embedded derivatives	1,225	2,721
Other	10,768	9,101
Prepaid expenses and other current assets	$ 53,846	$ 80,995

Related Parties (Details) - USD ($)	12 Months Ended
Related Parties (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Related party transaction	$ 0		$ 0
Curia Global
Related Party Transaction [Line Items]
Revenue from related parties		$ 3,700,000
Due from related parties		$ 800,000

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

+ Details

Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Accounts Payable and Accrued Liabilities [Line Items]
Accrued employee compensation	$ 35,037	$ 32,936
Other legal reserves	1,480	3,776
Accrued interest expense	26,681	23,291
Embedded derivatives	414	3,508
Professional fees	12,691	6,436
Accrued utilities	2,056	1,906
Insurance accrual	2,922	2,392
Accrued taxes	2,407	2,567
Other	3,495	5,318
Accrued liabilities	122,471	490,130
Georgia EO litigation settlement reserve
Accounts Payable and Accrued Liabilities [Line Items]
Litigation settlement reserve	35,000	0
Illinois EO litigation settlement reserve
Accounts Payable and Accrued Liabilities [Line Items]
Litigation settlement reserve	$ 288	$ 408,000

Accrued Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Payables and Accruals [Abstract]

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Accrued employee compensation	$	35,037	$	32,936
Georgia EO litigation settlement reserve	35,000		—
Illinois EO litigation settlement reserve	288		408,000
Other legal reserves	1,480		3,776
Accrued interest expense	26,681		23,291
Embedded derivatives	414		3,508
Professional fees	12,691		6,436
Accrued utilities	2,056		1,906
Insurance accrual	2,922		2,392
Accrued taxes	2,407		2,567
Other	3,495		5,318
Accrued liabilities	$	122,471	$	490,130

Financial Instruments and Financial Risk - Derivative Instruments (Details) - USD ($)	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022	May 31, 2022	Oct. 31, 2021
Derivative [Line Items]
Notional Amount	$ 1,721,100,000		$ 2,331,400,000
Derivative asset	11,624,000		37,485,000
Derivative liabilities	414,000		3,780,000
Derivatives Designated in Hedge Relationships \| Interest rate caps
Derivative [Line Items]
Notional Amount	1,000,000,000		2,000,000,000	$ 1,000,000,000	$ 1,000,000,000
Derivative asset	8,763,000		34,764,000
Derivative liabilities	0		0
Derivatives Designated in Hedge Relationships \| Interest Rate Swap
Derivative [Line Items]
Notional Amount	400,000,000.0	$ 400,000,000	0
Derivative asset	1,487,000		0
Derivative liabilities	0		0
Derivatives Not Designated in Hedge Relationships \| Foreign currency forward contracts
Derivative [Line Items]
Notional Amount	171,000,000.0		151,500,000
Derivative asset	149,000		0
Derivative liabilities	9,000		272,000
Derivatives Not Designated in Hedge Relationships \| Embedded derivatives(a)
Derivative [Line Items]
Notional Amount	150,100,000		179,900,000
Derivative asset	1,225,000		2,721,000
Derivative liabilities	$ 405,000		$ 3,508,000

Long-Term Debt - Senior Secured Credit Facilities (Narrative) (Details) - USD ($)				12 Months Ended
	Feb. 23, 2023	Jan. 09, 2023	Sep. 19, 2022	Dec. 31, 2023	Dec. 31, 2022	Mar. 21, 2023	Dec. 13, 2019
Debt Instrument [Line Items]
Total long-term debt				$ 2,260,600,000	$ 1,963,550,000
Asset Transfer Case \| Pending Litigation
Debt Instrument [Line Items]
Amount awarded to other party	$ 408,000,000
Illinois EO litigation settlement \| Pending Litigation
Debt Instrument [Line Items]
Amount awarded to other party		$ 408,000,000	$ 358,700,000	408,000,000
Base amount for default				$ 100,000,000
Triggering period for default				60 days
Term loan, due 2026 \| Secured Debt
Debt Instrument [Line Items]
Total long-term debt				$ 1,763,100,000	$ 1,763,100,000
Weighted average interest rate				7.95%	4.63%
Term loan, due 2026 \| Secured Debt \| Minimum
Debt Instrument [Line Items]
Weighted average interest rate				0.50%
Term loan, due 2026 \| Secured Debt \| Secured Overnight Financing Rate (SOFR) \| One-Month Interest Periods
Debt Instrument [Line Items]
Basis spread adjustment				0.11448%
Term loan, due 2026 \| Secured Debt \| Secured Overnight Financing Rate (SOFR) \| Three-Month Interest Periods
Debt Instrument [Line Items]
Basis spread adjustment				0.26161%
Term loan, due 2026 \| Secured Debt \| Secured Overnight Financing Rate (SOFR) \| Six-Month Interest Periods
Debt Instrument [Line Items]
Basis spread adjustment				0.42826%
Term loan B, due 2026 \| Secured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 500,000,000
Total long-term debt				$ 497,500,000
Weighted average interest rate				8.90%
Prepayment period without penalty	6 months
Principal balance payment, percent of amount outstanding	1.00%
Annual principal payment	$ 5,000,000
Term loan B, due 2026 \| Secured Debt \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate	3.75%
Term loan B, due 2026 \| Secured Debt \| Alternative Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%
First Lien Notes due 2026 \| Secured Debt \| Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate				0.10%
First Lien Notes due 2026 \| Secured Debt \| Secured Overnight Financing Rate (SOFR) \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate				0.00%
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 423,800,000
Revolving Credit Facility \| Senior Secured Credit Facilities
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 423,800,000
Total long-term debt					$ 200,000,000
Weighted average interest rate				7.47%	6.21%
Extinguishment of debt	$ 200,000,000
Debt outstanding				$ 0	$ 200,000,000
Letters of credit outstanding, amount				23,700,000
Unused borrowing capacity				$ 400,100,000
Revolving Credit Facility \| First Lien Notes due 2026
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 165,100,000
Revolving Credit Facility \| First Lien Notes due 2026 \| Secured Debt
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 76,300,000

Inventories

12 Months Ended

Dec. 31, 2023

Inventory Disclosure [Abstract]

Inventories

Inventories consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Raw materials and supplies	$	43,411	$	36,402
Work-in-process	471		584
Finished goods	4,670		276
	48,552		37,262
Reserve for excess and obsolete inventory	(236)		(117)
Inventories, net	$	48,316	$	37,145

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating Loss Carryforwards [Line Items]
Deferred income taxes	$ 64,454,000	$ 68,024,000
Unrecognized tax benefits, gross reserve	0	0
Tax benefit attributable to holiday	1,100,000	600,000
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	235,000,000	0
Operating loss carryforwards, valuation allowance	6,800,000	0
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	23,400,000	29,300,000
Operating loss carryforwards, valuation allowance	4,400,000	3,000,000
Deferred income taxes	0	0
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	298,800,000	28,300,000
Operating loss carryforwards, not subject to expiration	103,600,000	103,600,000
Operating loss carryforwards, valuation allowance	$ 11,300,000	$ 1,900,000

Goodwill and Other Intangible Assets

12 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Other Intangible Assets

Changes to goodwill during the years ended December 31, 2023 and 2022 were as follows:


(thousands of U.S. dollars)	Sterigenics		Nordion		Nelson Labs		Total
Goodwill at January 1, 2022	$	660,743	$	288,905	$	170,672	$	1,120,320
RCA acquisition measurement period adjustments	—		—		4,645		4,645
Changes due to foreign currency exchange rates	(3,285)		(17,939)		(1,973)		(23,197)
Goodwill at December 31, 2022	657,458		270,966		173,344		1,101,768
Changes due to foreign currency exchange rates	2,430		5,963		1,029		9,422
Goodwill at December 31, 2023	$	659,888	$	276,929	$	174,373	$	1,111,190

Other intangible assets consisted of the following:


(thousands of U.S. dollars)	Gross Carrying Amount		Accumulated Amortization
As of December 31, 2023
Finite-lived intangible assets
Customer relationships	$	657,673	$	485,188
Proprietary technology	84,918		56,846
Trade names	2,567		1,207
Land-use rights	8,756		1,855
Sealed source and supply agreements	208,919		107,561
Other	4,517		2,905
Total finite-lived intangible assets	967,350		655,562

Indefinite-lived intangible assets
Regulatory licenses and other(a)	78,684		—
Trade names / trademarks	25,846		—
Total indefinite-lived intangible assets	104,530		—
Total	$	1,071,880	$	655,562


As of December 31, 2022	Gross Carrying Amount		Accumulated Amortization
Finite-lived intangible assets
Customer relationships	$	652,811	$	422,277
Proprietary technology	86,054		50,952
Trade names	2,553		701
Land-use rights	8,986		1,683
Sealed source and supply agreements	204,391		93,034
Other	4,469		1,979
Total finite-lived intangible assets	959,264		570,626

Indefinite-lived intangible assets
Regulatory licenses and other(a)	76,978		—
Trade names / trademarks	25,649		—
Total indefinite-lived intangible assets	102,627		—
Total	$	1,061,891	$	570,626

(a)Includes certain transportation certifications, a class 1B nuclear license and other intangibles related to obtaining such licensure. These assets are considered indefinite-lived as the decision for renewal by the Canadian Nuclear Safety Commission is highly based on a licensee’s previous assessments, reported incidents, and annual compliance and inspection results. New applications for license can take a significant amount of time and cost; whereas an existing licensee with a historical record of compliance and current operating conditions more than likely ensures renewal for another 10 year license period as Nordion has demonstrated over its 75 years of history.

Amounts include the impact of foreign currency translation. Fully amortized amounts are written off.

Amortization expense for finite-lived intangible assets was $81.3 million, $81.6 million, and $86.8 million for the years ended December 31, 2023, 2022 and 2021, respectively. $63.8 million, $62.9 million, and $63.8 million was included in “Amortization of intangible assets” in the Consolidated Statements of Operations and Comprehensive Income (Loss) for the years ended December 31, 2023, 2022 and 2021, whereas the remainder was included in “Cost of revenues.”

The estimated aggregate amortization expense for finite-lived intangible assets for each of the next five years and thereafter is as follows:


(thousands of U.S. dollars)
2024	$	80,187
2025	42,735
2026	22,514
2027	21,438
2028	20,890
Thereafter	124,024
Total	$	311,788

The weighted-average remaining useful life of the finite-lived intangible assets was approximately 9.0 years as of December 31, 2023.

Recent Accounting Standards	12 Months Ended
Recent Accounting Standards	Dec. 31, 2023
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standards	Recent Accounting Standards Adoption of Accounting Standard Updates Effective January 1, 2023, we adopted Accounting Standards Update (“ASU”) ASU 2021-08-Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”). The amendments in ASU 2021-08 require that an acquiring entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). At the acquisition date, an acquirer should account for the related revenue contracts in accordance with ASC Topic 606 as if it had originated the contracts. The adoption of this standard did not have a material impact on our consolidated financial statements and disclosures. ASUs Issued But Not Yet Adopted In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-07-Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The amendments in ASU 2023-07 require an entity to provide enhanced disclosures about significant segment expenses. The amendments in this ASU are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The Company is in the process of evaluating the impact of this standard on our consolidated financial statements and disclosures. In December 2023, the FASB issued ASU 2023-09-Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The amendments in this ASU require entities to disclose, on an annual basis, specific categories in the reconciliation of the provision (benefit) for income taxes to the statutory rate and provide additional information for reconciling items that meet a quantitative threshold. Additionally, the update requires entities to disclose a disaggregation of taxes paid by category (federal, state and foreign taxes) as well as individual jurisdictions. For public business entities, the amendments in this ASU are effective for annual periods beginning after December 15, 2024. The Company is in the process of evaluating the impact of this standard on our consolidated financial statements and disclosures.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

+ References

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+ Details

Stockholders’ Equity	12 Months Ended
Stockholders’ Equity	Dec. 31, 2023
Equity [Abstract]
Stockholders’ Equity	Stockholders’ Equity Common Stock The Company completed its IPO in the fourth quarter of 2020 and shares began trading on Nasdaq on November 20, 2020. Prior to the completion of the IPO, the Company amended and restated its certificate of incorporation to authorize 1,200,000,000 shares of common stock, par value $0.01 per share, and reclassify all 3,000 shares of its common stock then outstanding as 232,400,200 shares. Upon completion of the IPO, 284,421,755 shares of common stock were outstanding. Voting Rights. Holders of common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders, subject to certain restrictions described in the certificate of incorporation. Dividends. Subject to preferences that may be applicable to any then outstanding preferred stock, holders of our common stock are entitled to receive ratably those dividends, if any, as may be declared by the board of directors out of legally available funds. Liquidation, Dissolution, and Winding Up. In the event of liquidation, dissolution or winding up, the holders of the Company’s common stock will be entitled to share equally and ratably in the net assets legally available for distribution to stockholders after the payment of all of debts and other liabilities, subject to the prior rights of any preferred stock then outstanding. Preferred Stock In addition, prior to the completion of the IPO, the Company’s amended and restated certificate of incorporation authorized 120,000,000 shares of preferred stock, par value $0.01 per share. The board of directors may issue preferred stock, without stockholder approval, in such series and with such designations, preferences, conversion or other rights, voting powers and qualifications, limitations or restrictions thereof, as the board of directors deems appropriate. Corporate Reorganization prior to the IPO Sotera Health Company was incorporated in November 2017 as the parent company for Sterigenics, Nordion and Nelson Labs under the name Sotera Health Topco, Inc. On October 23, 2020, the Company changed its name from Sotera Health Topco, Inc. to Sotera Health Company. Prior to the IPO, the Company was a direct wholly owned subsidiary of Sotera Health Topco Parent, L.P. (“Topco Parent”). Under the terms of the corporate reorganization completed prior to the IPO, Topco Parent distributed the shares of Sotera Health Company common stock to its partners in accordance with the limited partnership agreement of Topco Parent. Ownership of Topco Parent and Related Distributions Prior to the IPO, Topco Parent had four outstanding classes of partnership units: (1) Class A Units; (2) Class B-1 Units, which were subject to time-based vesting; (3) Class B-2 Units, which were subject to performance-based vesting; and (4) Class D Units. Each class of units was subject to the terms of the limited partnership agreement of Topco Parent. The Class A Units, Class B Units and Class D Units are referred to collectively as the “Units.” Pursuant to the terms of the corporate reorganization, Topco Parent made an in-kind distribution of the 232,400,200 shares of the Company’s common stock then outstanding to its limited partners in accordance with the terms of its limited partnership agreement, net of any previously unrecouped tax distributions. The value of a share of common stock was measured by the initial public offering price. All shares of the Company’s common stock held by Topco Parent were distributed to the holders of the Units. With respect to shares of common stock distributed in respect of any Class B-1 Units that were unvested as of the distribution and all of the Class B-2 Units (as none of the Class B-2 Units were vested as of the distribution), such shares are subject to the same vesting and forfeiture restrictions that applied to such unvested Class B-1 and Class B-2 Units prior to the distribution as described in Note 16, “Share-Based Compensation”. Following the distribution of the shares of the Company’s common stock, Topco Parent entered into dissolution. Following the Corporate reorganization, the Company completed its IPO of 53,590,000 shares of its common stock at a public offering price of $23.00 per share, for proceeds of approximately $1,156.0 million, net of underwriting discounts and issuance costs. In addition, we entered into agreements with certain executive officers to repurchase shares of our common stock beneficially owned by them in private transactions at a purchase price per share equal to the initial public offering price per share of our common stock less the underwriting discounts and commissions payable thereon. The total number of shares repurchased from certain executive officers in the fourth quarter of 2020 was 1,568,445. On March 22, 2021, we closed an underwritten secondary offering of our common stock, at a price to the public of $27.00 per share, in which all 25,000,000 shares were offered by selling stockholders, including Warburg Pincus, GTCR and certain current and former members of our management. In addition, the selling stockholders granted the underwriters a 30-day option to purchase up to an additional 3,750,000 shares of common stock. The Company did not offer any shares in the offering and did not receive any of the proceeds from the offering.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
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-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (a)
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
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-Paragraph 6
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-URI https://asc.fasb.org//1943274/2147481004/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Subparagraph (a)
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Stockholders’ Equity (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended
	Mar. 22, 2021	Nov. 18, 2020	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2020	Dec. 17, 2020	Nov. 19, 2020	Nov. 17, 2020
Equity [Abstract]
Common stock, shares authorized (in shares)				1,200,000,000	1,200,000,000				1,200,000,000
Common stock, par value (in dollars per share)				$ 0.01	$ 0.01				$ 0.01
Common stock, shares outstanding (in shares)		3,000						284,421,755	232,400,200
Preferred stock, shares authorized (in shares)				120,000,000	120,000,000				120,000,000
Preferred stock, par value (in dollars per share)				$ 0.01	$ 0.01		$ 0.01
Executive Officers
Shareholders' Equity [Line Items]
Repurchase of shares (in shares)			1,568,445
Common Stock
Equity [Abstract]
Common stock, shares outstanding (in shares)			282,985,000	282,830,000	282,421,000	283,248,000
IPO \| Common Stock
Shareholders' Equity [Line Items]
Number of shares sold (in shares)		53,590,000
Sale of stock (in dollars per share)		$ 23.00
Consideration received		$ 1,156.0
Secondary Offering \| Common Stock
Shareholders' Equity [Line Items]
Number of shares sold (in shares)	25,000,000
Sale of stock (in dollars per share)	$ 27.00
Secondary Offering \| Common Stock \| Underwriters
Shareholders' Equity [Line Items]
Number of shares sold (in shares)	3,750,000
Period of option to purchase	30 days

Segment and Geographic Information - Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net revenues	$ 1,049,288	$ 1,003,687	$ 931,478
United States
Segment Reporting Information [Line Items]
Net revenues	590,967	579,018	527,907
Canada
Segment Reporting Information [Line Items]
Net revenues	192,050	188,741	177,875
Europe
Segment Reporting Information [Line Items]
Net revenues	187,542	166,025	161,810
Other
Segment Reporting Information [Line Items]
Net revenues	$ 78,729	$ 69,903	$ 63,886
Asia
Segment Reporting Information [Line Items]
Percent of total revenues	3.00%	3.00%	3.00%
Latin America
Segment Reporting Information [Line Items]
Percent of total revenues	3.00%	3.00%	3.00%

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479941/924-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
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-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
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-Section 50
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-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
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-Publisher FASB
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-4

+ Details

Significant Accounting Policies - Additional Information (Details)		12 Months Ended
	Oct. 01, 2023 USD ($)	Dec. 31, 2023 segment	Dec. 31, 2021
Accounting Policies [Abstract]
Number of reportable segments		3
Number of operating segments		3
Goodwill impairment \| $	$ 0
Performance Shares \| Minimum \| 2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year
Performance Shares \| Maximum \| 2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Pre-IPO B-1 \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			5 years

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Schedule of Property, Plant and Equipment

Depreciation is computed using the assets’ estimated useful lives as presented below:


Buildings and building improvements			15–44 years
Machinery and equipment			3–30 years
Leasehold improvements			2–20 years
Furniture and fixtures			3–10 years
Computer hardware and software			1–7 years

Property, plant, and equipment, net, consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Land and buildings	$	345,309	$	317,930
Leasehold improvements	82,582		67,386
Machinery, equipment, including Co-60	710,000		577,670
Furniture and fixtures	8,754		7,747
Computer hardware and software	51,437		44,796
Asset retirement costs	6,590		4,255
Construction-in-progress	247,019		193,639
	1,451,691		1,213,423
Less accumulated depreciation	(504,777)		(438,896)
Property, plant and equipment, net	$	946,914	$	774,527

Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 81,348	$ 81,554	$ 86,742
Finite-lived intangible assets, remaining amortization period	9 years
Other
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 81,300	81,600	86,800
Other \| Selling, General and Administrative Expenses
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 63,800	$ 62,900	$ 63,800

Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues:
Total net revenues	$ 1,049,288	$ 1,003,687	$ 931,478
Cost of revenues:
Total cost of revenues	472,130	446,683	412,806
Gross profit	577,158	557,004	518,672
Operating expenses:
Selling, general and administrative expenses	236,667	245,714	198,158
Amortization of intangible assets	63,799	62,940	63,781
Total operating expenses	300,466	308,654	261,939
Operating income	276,692	248,350	256,733
Interest expense, net	142,878	80,144	74,192
Impairment of investment in unconsolidated affiliate	0	9,613	0
Loss on extinguishment of debt	0	0	20,681
Foreign exchange loss	159	145	1,345
Other income, net	(7,372)	(6,441)	(15,201)
Income (loss) before income taxes	106,027	(243,111)	175,716
Provision (benefit) for income taxes	54,651	(9,541)	58,595
Net income (loss)	51,376	(233,570)	117,121
Less: Net income attributable to noncontrolling interests	0	0	239
Net income (loss) attributable to Sotera Health Company	51,376	(233,570)	116,882
Other comprehensive income (loss) net of tax:
Pension and post-retirement benefits (net of taxes of $(3,420), $7,022 and $8,924, respectively)	(10,506)	20,790	26,562
Interest rate derivatives (net of taxes of $(5,467), $7,387 and $142, respectively)	(15,697)	20,939	404
Foreign currency translation	40,174	(64,816)	(16,395)
Comprehensive income (loss)	65,347	(256,657)	127,692
Less: comprehensive income attributable to noncontrolling interests	0	0	534
Comprehensive income (loss) attributable to Sotera Health Company	$ 65,347	$ (256,657)	$ 127,158
Earnings (Loss) per share:
Basic (in dollars per share)	$ 0.18	$ (0.83)	$ 0.41
Diluted (in dollars per share)	$ 0.18	$ (0.83)	$ 0.41
Weighted average number of shares outstanding:
Basic (in shares)	281,008	280,096	279,228
Diluted (in shares)	283,222	280,096	279,382
Georgia EO litigation settlement
Operating expenses:
Litigation settlement	$ 35,000	$ 0	$ 0
Illinois EO litigation settlement
Operating expenses:
Litigation settlement	0	408,000	0
Service
Revenues:
Total net revenues	905,598	864,828	805,501
Cost of revenues:
Total cost of revenues	418,611	390,860	357,205
Product
Revenues:
Total net revenues	143,690	138,859	125,977
Cost of revenues:
Total cost of revenues	$ 53,519	$ 55,823	$ 55,601

Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings (loss):
Net income (loss)	$ 51,376	$ (233,570)	$ 117,121
Less: Net income attributable to noncontrolling interests	0	0	239
Less: Allocation to participating securities	287	0	1,524
Less: Allocation to participating securities	287	0	1,524
Net income (loss) attributable to Sotera Health Company common stockholders (basic)	51,089	(233,570)	115,358
Net income (loss) attributable to Sotera Health Company common stockholders (diluted)	$ 51,089	$ (233,570)	$ 115,358
Weighted Average Common Shares:
Weighted-average common shares outstanding - basic (in shares)	281,008,000	280,096,000	279,228,000
Dilutive effect of potential common shares (in shares)	2,213,000	0	154,000
Weighted-average common shares outstanding - diluted (in shares)	283,222,000	280,096,000	279,382,000
Earnings (loss) per Common Share:
Net income (loss) per common share attributable to Sotera Health Company common stockholders - basic (in dollars per share)	$ 0.18	$ (0.83)	$ 0.41
Net income (loss) per common share attributable to Sotera Health Company common stockholders - diluted (in dollars per share)	$ 0.18	$ (0.83)	$ 0.41
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	4,399,000	8,457,000	2,407,000
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	291,000	2,467,000	4,000
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	4,108,000	5,990,000	2,403,000

Financial Instruments and Financial Risk - Additional Information (Details)	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2023 USD ($)	May 31, 2022 USD ($) instrument	Oct. 31, 2021 USD ($) instrument
Derivative [Line Items]
Notional amount	$ 1,721,100,000	$ 2,331,400,000
Derivative liabilities	414,000	3,780,000
Interest rate derivatives, net of tax	(15,697,000)	20,939,000	$ 404,000
Allowance for uncollectible accounts	4,689,000	1,871,000
Derivatives Designated in Hedge Relationships
Derivative [Line Items]
Interest rate derivatives, net of tax	8,700,000
Derivatives Designated in Hedge Relationships \| Interest Rate Swap
Derivative [Line Items]
Number of instruments held \| instrument					2
Notional amount	400,000,000.0	0		$ 400,000,000
Derivative liabilities	0	0
Derivatives Designated in Hedge Relationships \| Interest rate caps
Derivative [Line Items]
Notional amount	1,000,000,000	2,000,000,000			$ 1,000,000,000	$ 1,000,000,000
Percent of borrowing limitation due to cash flow exposure					3.50%	1.00%
Derivative liabilities	0	0
Derivatives Designated in Hedge Relationships \| Interest Rate Cap October 2017
Derivative [Line Items]
Number of instruments held \| instrument						2
Option premium					$ 4,100,000	$ 1,800,000
Derivatives Not Designated in Hedge Relationships \| Foreign currency forward contracts
Derivative [Line Items]
Notional amount	171,000,000.0	151,500,000
Derivative liabilities	$ 9,000	$ 272,000

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pay vs Performance Disclosure
Net income	$ 51,376	$ (233,570)	$ 116,882

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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+ Details

Leases - Non-Cash Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating leases	$ 4,559	$ 1,338	$ 8,742
Finance leases	$ 14,770	$ 18,286	$ 10,995

Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Goodwill

Changes to goodwill during the years ended December 31, 2023 and 2022 were as follows:


(thousands of U.S. dollars)	Sterigenics		Nordion		Nelson Labs		Total
Goodwill at January 1, 2022	$	660,743	$	288,905	$	170,672	$	1,120,320
RCA acquisition measurement period adjustments	—		—		4,645		4,645
Changes due to foreign currency exchange rates	(3,285)		(17,939)		(1,973)		(23,197)
Goodwill at December 31, 2022	657,458		270,966		173,344		1,101,768
Changes due to foreign currency exchange rates	2,430		5,963		1,029		9,422
Goodwill at December 31, 2023	$	659,888	$	276,929	$	174,373	$	1,111,190

Schedule of Acquired Finite-Lived Intangible Assets

Amortization of intangible assets is computed using the asset’s estimated useful lives as presented below:


Land-use rights			41 years
Customer contracts and related relationships			5–20 years
Proprietary technology			7–20 years
Trade name/trademark			5–8 years
Sealed source and supply agreements			7–20 years

Other intangible assets consisted of the following:


(thousands of U.S. dollars)	Gross Carrying Amount		Accumulated Amortization
As of December 31, 2023
Finite-lived intangible assets
Customer relationships	$	657,673	$	485,188
Proprietary technology	84,918		56,846
Trade names	2,567		1,207
Land-use rights	8,756		1,855
Sealed source and supply agreements	208,919		107,561
Other	4,517		2,905
Total finite-lived intangible assets	967,350		655,562

Indefinite-lived intangible assets
Regulatory licenses and other(a)	78,684		—
Trade names / trademarks	25,846		—
Total indefinite-lived intangible assets	104,530		—
Total	$	1,071,880	$	655,562


As of December 31, 2022	Gross Carrying Amount		Accumulated Amortization
Finite-lived intangible assets
Customer relationships	$	652,811	$	422,277
Proprietary technology	86,054		50,952
Trade names	2,553		701
Land-use rights	8,986		1,683
Sealed source and supply agreements	204,391		93,034
Other	4,469		1,979
Total finite-lived intangible assets	959,264		570,626

Indefinite-lived intangible assets
Regulatory licenses and other(a)	76,978		—
Trade names / trademarks	25,649		—
Total indefinite-lived intangible assets	102,627		—
Total	$	1,061,891	$	570,626

Schedule of Acquired Indefinite-lived Intangible Assets

Other intangible assets consisted of the following:


(thousands of U.S. dollars)	Gross Carrying Amount		Accumulated Amortization
As of December 31, 2023
Finite-lived intangible assets
Customer relationships	$	657,673	$	485,188
Proprietary technology	84,918		56,846
Trade names	2,567		1,207
Land-use rights	8,756		1,855
Sealed source and supply agreements	208,919		107,561
Other	4,517		2,905
Total finite-lived intangible assets	967,350		655,562

Indefinite-lived intangible assets
Regulatory licenses and other(a)	78,684		—
Trade names / trademarks	25,846		—
Total indefinite-lived intangible assets	104,530		—
Total	$	1,071,880	$	655,562


As of December 31, 2022	Gross Carrying Amount		Accumulated Amortization
Finite-lived intangible assets
Customer relationships	$	652,811	$	422,277
Proprietary technology	86,054		50,952
Trade names	2,553		701
Land-use rights	8,986		1,683
Sealed source and supply agreements	204,391		93,034
Other	4,469		1,979
Total finite-lived intangible assets	959,264		570,626

Indefinite-lived intangible assets
Regulatory licenses and other(a)	76,978		—
Trade names / trademarks	25,649		—
Total indefinite-lived intangible assets	102,627		—
Total	$	1,061,891	$	570,626

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The estimated aggregate amortization expense for finite-lived intangible assets for each of the next five years and thereafter is as follows:


(thousands of U.S. dollars)
2024	$	80,187
2025	42,735
2026	22,514
2027	21,438
2028	20,890
Thereafter	124,024
Total	$	311,788

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

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+ Details

Share-Based Compensation - Stock Options Assumptions (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share (in dollars per share)	$ 7.13	$ 4.86	$ 9.08
Expected term (years)	6 years	5 years 9 months 18 days	6 years 3 months 18 days
Risk-free interest rate	4.20%	3.40%	1.20%
Expected volatility	50.00%	45.70%	37.50%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
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Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
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Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Section 50
-Paragraph 2
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Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Section 50
-Paragraph 2
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Reference 23: http://www.xbrl.org/2003/role/disclosureRef
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Reference 24: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 2
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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Reference 27: http://www.xbrl.org/2003/role/disclosureRef
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Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Employee Benefits - Weighted Average Assumptions Used in the Measurement of Benefit Obligation (Details)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Defined benefit pension plan
Projected benefit obligation
Discount rate	4.65%	5.19%
Rate of compensation increase	3.00%	3.00%
Periodic benefit
Discount rate	5.19%	3.01%
Expected return on plan assets	6.50%	5.00%
Rate of compensation increase	3.00%	3.00%
Other post-retirement benefits plans
Projected benefit obligation
Discount rate	4.65%	5.19%
Rate of compensation increase	3.00%	3.00%
Initial health care cost trend rate	7.00%	7.00%
Ultimate health care cost trend rate	4.00%	4.00%
Years until ultimate trend rate is reached	16 years	18 years
Periodic benefit
Discount rate	5.19%	3.01%
Rate of compensation increase	3.00%	3.00%

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Allowance for uncollectible accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 1,871	$ 1,287	$ 708
Charges (credits) to costs and expense	4,313	1,009	1,132
Deductions	(1,502)	(419)	(408)
Translation Adjustments	7	(6)	(145)
Balance at End of Period	4,689	1,871	1,287
Deferred tax asset valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	105,600	52,080	43,765
Charges (credits) to costs and expense	19,682	53,945	8,455
Deductions	0	0	0
Translation Adjustments	153	(425)	(140)
Balance at End of Period	$ 125,435	$ 105,600	$ 52,080

Leases (Tables)

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Schedule of Lease Expense

The components of lease expense were as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Operating lease costs (a)	$	13,920	$	15,122	$	15,433
Finance lease costs:
Amortization of right of use assets	8,152		6,368		3,018
Interest on lease liabilities	4,394		3,454		2,506
Total finance lease costs	12,546		9,822		5,524
Total lease costs	$	26,466	$	24,944	$	20,957

(a)Includes $1.4 million, $1.3 million, and $0.9 million of short-term lease costs in the year ended December 31, 2023, 2022, and 2021, respectively.

Supplemental cash flow information related to leases was as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	10,067	$	11,112	$	12,494
Operating cash flow for finance leases	3,988		2,932		2,042
Finance cash flows for finance leases	1,823		1,066		901

Supplemental non-cash information was as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Lease liabilities arising from obtaining right-of-use assets:
Operating leases	$	4,559	$	1,338	$	8,742
Finance leases	14,770		18,286		10,995

Schedule of Lease Term and Discount Rate

Lease terms and discount rates were as follows:


	Year Ended December 31,
	2023		2022
Weighted average remaining lease term:
Operating leases	5.7 years		4.5 years
Finance leases	14.0 years		14.0 years
Weighted average discount rate:
Operating leases	5.92	%	5.88	%
Finance leases	5.76	%	5.48	%

Schedule of Maturity, Operating Lease

Maturities of lease liabilities as of December 31, 2023 are as follows:


(thousands of U.S. dollars)	Operating Leases		Finance Leases		Total
2024	$	7,357	$	12,579	$	19,936
2025	5,505		5,767		11,272
2026	5,077		5,737		10,814
2027	3,999		5,893		9,892
2028	2,926		6,063		8,989
2029 and Thereafter	6,165		74,337		80,502
Total lease payments	31,029		110,376		141,405
Less imputed interest	(5,008)		(37,812)		(42,820)
Total lease liabilities	$	26,021	$	72,564	$	98,585

Schedule of Maturity, Finance Lease

Maturities of lease liabilities as of December 31, 2023 are as follows:


(thousands of U.S. dollars)	Operating Leases		Finance Leases		Total
2024	$	7,357	$	12,579	$	19,936
2025	5,505		5,767		11,272
2026	5,077		5,737		10,814
2027	3,999		5,893		9,892
2028	2,926		6,063		8,989
2029 and Thereafter	6,165		74,337		80,502
Total lease payments	31,029		110,376		141,405
Less imputed interest	(5,008)		(37,812)		(42,820)
Total lease liabilities	$	26,021	$	72,564	$	98,585

Financial Instruments and Financial Risk - Activities of Derivative Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized loss (gain) on derivatives not designated as hedging instruments	$ (1,637)	$ 2,977	$ (1,195)
Interest rate caps
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized loss (gain) on derivatives not designated as hedging instruments	0	0	(1,185)
Realized gain on interest rate derivatives recorded in interest expense, net	(33,094)	(12,226)	0
Embedded derivatives(a)
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized loss (gain) on derivatives not designated as hedging instruments	(1,637)	1,324	(1,195)
Foreign currency forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss	(2,025)	3,931	(1,900)
Unrealized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss	$ (412)	$ 272	$ 0

- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of derivative instruments, including options, swaps, futures, and forward contracts, held at each balance sheet date, that was included in earnings for the period.

+ References + Details

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Net deferred tax assets
Net operating loss carryforwards	$ 71,552	$ 9,286
Net capital loss carryforwards	4,686	4,666
Reserves and accruals	26,591	121,685
Employee benefits and compensation	8,519	6,610
Asset retirement obligations	11,140	10,649
Lease liability	8,733	9,506
Disallowed interest carryforward	129,320	89,682
Other	10,806	6,561
Deferred tax assets before valuation allowance	271,347	258,645
Valuation allowance	(125,435)	(105,600)
Net deferred tax assets	145,912	153,045
Net deferred tax liabilities
Depreciation and amortization	(195,450)	(199,670)
Other	(9,923)	(17,298)
Total deferred tax liabilities	(205,373)	(216,968)
Net deferred tax liabilities	(59,461)	(63,923)
Deferred income taxes	4,993	4,101
Deferred income taxes	$ (64,454)	$ (68,024)

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Deficit	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interests
Beginning Balance (in shares) at Dec. 31, 2020		283,248
Beginning Balance at Dec. 31, 2020	$ 454,574	$ 2,860	$ (34,000)	$ 1,166,412	$ (589,128)	$ (93,842)	$ 2,272
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Acquisition of noncontrolling interests	(8,578)			(5,772)			(2,806)
Issuance of shares (in shares)		47
Issuance of shares	1,080	$ 0		1,080
Share-based compensation plans (in shares)		(310)
Share-based compensation plans	11,328		455	10,873
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	26,562					26,562
Foreign currency translation	(16,395)					(16,690)	295
Interest rate derivatives, net of tax	404					404
Net income (loss)	117,121				116,882		239
Ending Balance (in shares) at Dec. 31, 2021		282,985
Ending Balance at Dec. 31, 2021	586,096	$ 2,860	(33,545)	1,172,593	(472,246)	(83,566)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation plans (in shares)		(564)
Share-based compensation plans	20,799		3,770	17,029
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	20,790					20,790
Foreign currency translation	(64,816)					(64,816)	0
Interest rate derivatives, net of tax	20,939					20,939
Net income (loss)	(233,570)				(233,570)		0
Ending Balance (in shares) at Dec. 31, 2022		282,421
Ending Balance at Dec. 31, 2022	350,238	$ 2,860	(29,775)	1,189,622	(705,816)	(106,653)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation plans (in shares)		409
Share-based compensation plans	28,149		2,593	25,556
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	(10,506)					(10,506)
Foreign currency translation	40,174					40,174
Interest rate derivatives, net of tax	(15,697)					(15,697)
Net income (loss)	51,376				51,376
Ending Balance (in shares) at Dec. 31, 2023		282,830
Ending Balance at Dec. 31, 2023	$ 443,734	$ 2,860	$ (27,182)	$ 1,215,178	$ (654,440)	$ (92,682)	$ 0

Significant Accounting Policies - Estimated Useful Life (Details)	12 Months Ended
	Dec. 31, 2023
Land-use rights
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	41 years
Customer contracts and related relationships \| Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	5 years
Customer contracts and related relationships \| Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	20 years
Proprietary technology \| Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	7 years
Proprietary technology \| Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	20 years
Sealed source and supply agreements \| Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	7 years
Sealed source and supply agreements \| Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	20 years
Trade names \| Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	5 years
Trade names \| Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	8 years

Long-Term Debt

12 Months Ended

Dec. 31, 2023

Debt Disclosure [Abstract]

Long-Term Debt

Long-term debt consisted of the following:


(thousands of U.S. dollars)
As of December 31, 2023	Gross Amount		Unamortized Debt Issuance Costs		Unamortized Debt Discount		Net Amount
Term loan, due 2026	1,763,100		(1,606)		(10,298)		1,751,196
Term loan B, due 2026	497,500		(7,616)		(12,609)		477,275
	2,260,600		(9,222)		(22,907)		2,228,471
Less current portion	5,000		(76)		(127)		4,797
Long-term debt	$	2,255,600	$	(9,146)	$	(22,780)	$	2,223,674


(thousands of U.S. dollars)
As of December 31, 2022	Gross Amount		Unamortized Debt Issuance Costs		Unamortized Debt Discount		Net Amount
Term loan, due 2026	1,763,100		(2,140)		(13,845)		1,747,115
Revolving credit facility	200,000		(3,328)		—		196,672
Other long-term debt	450		(3)		—		447
	1,963,550		(5,471)		(13,845)		1,944,234
Less current portion	200,450		(3,331)		—		197,119
Long-term debt	$	1,763,100	$	(2,140)	$	(13,845)	$	1,747,115

Debt Facilities

Senior Secured Credit Facilities

On December 13, 2019, Sotera Health Holdings, LLC (“SHH”), our wholly owned subsidiary, entered into senior secured first lien credit facilities (the “Senior Secured Credit Facilities”), consisting of both a prepayable senior secured first lien term loan (the “Term Loan”) and a senior secured first lien revolving credit facility (the “Revolving Credit Facility”) pursuant to a first lien credit agreement (the “2019 Credit Agreement”). The Revolving Credit Facility and Term Loan mature on June 13, 2026, and December 13, 2026, respectively. After giving effect to the Revolving Credit Facility Amendment (defined below), the total borrowing capacity under the Revolving Credit Facility is $423.8 million. The Senior Secured Credit Facilities also provide SHH the right at any time and under certain conditions to request incremental term loans or incremental revolving credit commitments based on a formula defined in the Senior Secured Credit Facilities. As of December 31, 2023 and 2022, total borrowings under the Term Loan were $1,763.1 million. The weighted average interest rate on borrowings under the Term Loan for the year ended December 31, 2023 and 2022 was 7.95% and 4.63%, respectively.

On February 23, 2023, we entered into the First Lien Credit Agreement (the “2023 Credit Agreement”), which provides for, among other things, a new Term Loan B facility (the “2023 Term Loan”) in an aggregate principal amount of $500.0 million and bears interest, at the Company’s option, at a variable rate per annum equal to either (x) the Term Secured Overnight Financing Rate (“Term SOFR”) (as defined in the 2023 Credit Agreement) plus an applicable margin of 3.75% or (y) an alternative base rate (“ABR”) plus an applicable margin of 2.75%. The 2023 Credit Agreement is secured on a first priority basis on substantially all of our assets and is guaranteed by certain of our subsidiaries. It is prepayable without premium or penalty at any time six months after the closing date. The principal balance shall be paid at 1% of the aggregate principal amount ($5.0 million) per year, with the balance due at the end of 2026. The Company used the proceeds of the 2023 Term Loan to fund a previously announced $408.0 million EO litigation settlement in Cook County, Illinois and pay down the $200.0 million of existing borrowings under the Revolving Credit Facility concurrent with the funding of the 2023 Term Loan on February 23, 2023. The Company utilized the remaining proceeds to further enhance liquidity and for general corporate purposes. The weighted average interest rate on borrowings under the 2023 Term Loan for the year ended December 31, 2023 was 8.90%.

On March 21, 2023, the Company entered into an Incremental Facility Amendment to the First Lien Credit Agreement (“Revolving Credit Facility Amendment”), which provides for an increase in the commitments under the existing Revolving Credit Facility in an aggregate principal amount of $76.3 million. In addition, certain of the lenders providing revolving credit commitments provided additional commitments for the issuance of the letters of credit under the Revolving Credit Facility in an aggregate principal amount of $165.1 million. The Revolving Credit Facility Amendment also provides for the replacement of the reference interest rate option for Revolving Loans from London Interbank Offered Rate (“LIBOR”) to Secured Overnight Financing Rate (“SOFR”) plus an applicable credit spread adjustment of 0.10% (subject to a minimum floor of 0%). After giving effect to the Revolving Credit Facility Amendment, the aggregate amount of the lenders’ revolving commitments is $423.8 million. The maturity date of the Revolving Credit Facility remains June 13, 2026. The Company borrowed $200.0 million under the Revolving Credit Facility during the fourth quarter of 2022, which was repaid in the first quarter of 2023. As of December 31, 2023 and 2022 total borrowings outstanding on the Revolving Credit Facility were $0 and $200.0 million, respectively. The weighted average interest rate on outstanding borrowings under the Revolving Credit Facility for the years ended December 31, 2023 and 2022 was 7.47% and 6.21%, respectively.

The Senior Secured Credit Facilities and 2023 Credit Agreement contain additional covenants that, among other things, restrict, subject to certain exceptions, our ability and the ability of our restricted subsidiaries to engage in certain activities, such as incur indebtedness or permit to exist any lien on any property or asset now owned or hereafter acquired, as specified in the Senior Secured Credit Facilities and 2023 Credit Agreement. The Senior Secured Credit Facilities and 2023 Credit Agreement also contain certain customary affirmative covenants and events of default, including upon a change of control. An event of default under the Senior Secured Credit Facilities and 2023 Credit Agreement would occur if the Company or certain of its subsidiaries received one or more enforceable judgments in an aggregate amount in excess of $100.0 million and the judgments were not stayed or remained undischarged for a period of sixty consecutive days or if, to enforce such judgments, a judgment creditor were to attach liens upon assets that are material to the business and operations of the Company and certain of its subsidiaries as a whole. As of December 31, 2023, we were in compliance with all of the Senior Secured Credit Facilities and 2023 Credit Agreement covenants.

All of SHH’s obligations under the Senior Secured Credit Facilities and 2023 Credit Agreement are unconditionally guaranteed by the Company and each existing and subsequently acquired or organized direct or indirect wholly-owned domestic restricted subsidiary of the Company, with customary exceptions including, among other things, where providing such guarantees is not permitted by law, regulation or contract or would result in material adverse tax consequences. All obligations under the Senior Secured Credit Facilities and 2023 Credit Agreement, and the guarantees of such obligations, are secured by substantially all assets of the borrower and guarantors, subject to permitted liens and other exceptions and exclusions, as outlined in the Senior Secured Credit Facilities and 2023 Credit Agreement.

Outstanding letters of credit are collateralized by encumbrances against the Revolving Credit Facility and the collateral pledged thereunder, or by cash placed on deposit with the issuing bank. As of December 31, 2023, the Company had $23.7 million of letters of credit issued against the Revolving Credit Facility, resulting in total availability under the Revolving Credit Facility of $400.1 million.

Term Loan Interest Rate Risk Management

The Company utilizes interest rate derivatives to reduce the variability of cash flows in the interest payments associated with our variable rate debt due to changes in LIBOR (up to June 22, 2023) and Term SOFR. For additional information on the derivative instruments described above, refer to Note 21, “Financial Instruments and Financial Risk”, “Derivative Instruments.”

LIBOR Transition

Publication of all U.S. LIBOR tenors ceased after June 30, 2023. To align with the market phaseout of LIBOR, SHH entered into an amendment to the Senior Secured Credit Facilities to replace the LIBOR-based reference interest rate option under the Term Loan with a reference interest rate option based on Term SOFR plus an applicable credit spread adjustment of 0.11448% (for one-month interest periods), 0.26161% (for three-month interest periods) and 0.42826% (for six-month interest periods) (in all cases, subject to a minimum floor of 0.50%).

In accordance with ASC 848 Reference Rate Reform, we have elected to apply certain optional expedients for contract modifications and hedging relationships for derivative instruments impacted by the benchmark interest rate transition. The optional expedients remove the requirement to remeasure contract modifications or dedesignate hedging relationships impacted by reference rate reform.

Aggregate Maturities

Aggregate maturities of the Company’s long-term debt, excluding debt discounts, as of December 31, 2023, are as follows:


(thousands of U.S. dollars)
2024	$	5,000
2025	5,000
2026	2,250,600


Thereafter	—
Total	$	2,260,600

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Allowance for uncollectible accounts	$ 4,689	$ 1,871
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,200,000,000	1,200,000,000
Common stock, shares issued (in shares)	286,037,000	286,037,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	120,000,000	120,000,000
Preferred stock, shares issued (in shares)	0	0
Treasury stock (in shares)	3,207,000	3,616,000

Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Schedule of Property, Plant and Equipment

Depreciation is computed using the assets’ estimated useful lives as presented below:


Buildings and building improvements			15–44 years
Machinery and equipment			3–30 years
Leasehold improvements			2–20 years
Furniture and fixtures			3–10 years
Computer hardware and software			1–7 years

Property, plant, and equipment, net, consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Land and buildings	$	345,309	$	317,930
Leasehold improvements	82,582		67,386
Machinery, equipment, including Co-60	710,000		577,670
Furniture and fixtures	8,754		7,747
Computer hardware and software	51,437		44,796
Asset retirement costs	6,590		4,255
Construction-in-progress	247,019		193,639
	1,451,691		1,213,423
Less accumulated depreciation	(504,777)		(438,896)
Property, plant and equipment, net	$	946,914	$	774,527

Schedule of Acquired Finite-Lived Intangible Assets

Amortization of intangible assets is computed using the asset’s estimated useful lives as presented below:


Land-use rights			41 years
Customer contracts and related relationships			5–20 years
Proprietary technology			7–20 years
Trade name/trademark			5–8 years
Sealed source and supply agreements			7–20 years

Other intangible assets consisted of the following:


(thousands of U.S. dollars)	Gross Carrying Amount		Accumulated Amortization
As of December 31, 2023
Finite-lived intangible assets
Customer relationships	$	657,673	$	485,188
Proprietary technology	84,918		56,846
Trade names	2,567		1,207
Land-use rights	8,756		1,855
Sealed source and supply agreements	208,919		107,561
Other	4,517		2,905
Total finite-lived intangible assets	967,350		655,562

Indefinite-lived intangible assets
Regulatory licenses and other(a)	78,684		—
Trade names / trademarks	25,846		—
Total indefinite-lived intangible assets	104,530		—
Total	$	1,071,880	$	655,562


As of December 31, 2022	Gross Carrying Amount		Accumulated Amortization
Finite-lived intangible assets
Customer relationships	$	652,811	$	422,277
Proprietary technology	86,054		50,952
Trade names	2,553		701
Land-use rights	8,986		1,683
Sealed source and supply agreements	204,391		93,034
Other	4,469		1,979
Total finite-lived intangible assets	959,264		570,626

Indefinite-lived intangible assets
Regulatory licenses and other(a)	76,978		—
Trade names / trademarks	25,649		—
Total indefinite-lived intangible assets	102,627		—
Total	$	1,061,891	$	570,626

Prepaid Expenses and Other Current Assets

12 Months Ended

Dec. 31, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Prepaid taxes	$	4,129	$	26,598
Prepaid business insurance	7,174		9,964
Prepaid rent	1,150		998
Customer contract assets	17,785		19,777
Insurance and indemnification receivables	—		3,724
Current deposits	715		660
Prepaid maintenance contracts	422		324
Value added tax receivable	4,306		1,640
Prepaid software licensing	2,503		1,832
Stock supplies	3,669		3,656
Embedded derivatives	1,225		2,721
Other	10,768		9,101
Prepaid expenses and other current assets	$	53,846	$	80,995

Accrued Liabilities

12 Months Ended

Dec. 31, 2023

Payables and Accruals [Abstract]

Accrued Liabilities

Accrued liabilities consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Accrued employee compensation	$	35,037	$	32,936
Georgia EO litigation settlement reserve	35,000		—
Illinois EO litigation settlement reserve	288		408,000
Other legal reserves	1,480		3,776
Accrued interest expense	26,681		23,291
Embedded derivatives	414		3,508
Professional fees	12,691		6,436
Accrued utilities	2,056		1,906
Insurance accrual	2,922		2,392
Accrued taxes	2,407		2,567
Other	3,495		5,318
Accrued liabilities	$	122,471	$	490,130

Segment and Geographic Information

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Segment and Geographic Information

We identify our operating segments based on the way we manage, evaluate and internally report our business activities for purposes of allocating resources and assessing performance. We have three reportable segments: Sterigenics, Nordion and Nelson Labs. We have determined our reportable segments based upon an assessment of organizational structure, service types, and internally prepared financial statements. Our chief operating decision maker evaluates performance and allocates resources based on net revenues and segment income after the elimination of intercompany activities. The accounting policies of our reportable segments are the same as those described in Note 1, “Significant Accounting Policies”.

Sterigenics

Sterigenics provides outsourced terminal sterilization and irradiation services for the medical device, pharmaceutical, food safety and advanced applications markets using three major technologies: gamma irradiation, EO processing and E-beam irradiation.

Nordion

Nordion is a leading global provider of Co-60 used in the sterilization and irradiation processes for the medical device, pharmaceutical, food safety, and high-performance materials industries, as well as in the treatment of cancer. In addition, Nordion is a leading global provider of gamma irradiation systems.

Nelson Labs

Nelson Labs provides outsourced microbiological and analytical chemistry testing and advisory services for the medical device and pharmaceutical industries.

Segment Revenue Concentrations

For the year ended December 31, 2023, three customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 20.1%, 14.8%, and 13.9% of the total segment’s external net revenues for the year ended December 31, 2023. For the year ended December 31, 2022, five customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 17.7%, 13.6%, 11.2%, 10.7%, and 10.2% of the total segment’s external net revenues for the year ended December 31, 2022. For the year ended December 31, 2021, four customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 15.1%, 12.7%, 11.5%, 11.1% of the total segment’s external net revenues for the year ended December 31, 2021.

Financial information for each of our segments is presented in the following table:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Segment revenues(a)
Sterigenics	$	667,130	$	626,646	$	571,829
Nordion	160,459		153,639		140,507
Nelson Labs	221,699		223,402		219,142
Total net revenues	$	1,049,288	$	1,003,687	$	931,478
Segment income(b)
Sterigenics	$	362,212	$	339,144	$	310,470
Nordion	96,678		89,477		82,673
Nelson Labs	69,139		77,628		88,086
Total segment income	$	528,029	$	506,249	$	481,229

(a)Revenues are reported net of intersegment sales. Our Nordion segment recognized $43.9 million, $52.4 million and $34.1 million in revenues from sales to our Sterigenics segment for the years ended December 31, 2023, 2022 and 2021, respectively, that is not reflected in net revenues in the table above. Intersegment sales for Sterigenics and Nelson Labs are immaterial for all periods presented.

(b)Segment income is only provided on a net basis to the chief operating decision maker and is reported net of intersegment profits.

Corporate operating expenses for executive management, accounting, information technology, legal, human resources, treasury, investor relations, corporate development, tax, purchasing, and marketing not directly incurred by a segment are allocated to the segments based on total net revenue. Corporate operating expenses that are directly incurred by a segment are reflected in each segment’s income.

Capital expenditures by segment for the years ended December 31, 2023, 2022 and 2021 were as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Sterigenics	$	163,043	$	144,027	$	73,753
Nordion	38,351		26,575		21,292
Nelson Labs	13,581		11,776		7,117
Total capital expenditures	$	214,975	$	182,378	$	102,162

Total assets and depreciation and amortization expense by segment are not readily available and are not reported separately to the chief operating decision maker.

A reconciliation of segment income to consolidated income (loss) before taxes is as follows:


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
Segment income	$	528,029	$	506,249	$	481,229
Less adjustments:
Interest expense, net(a)	116,068		78,490		74,192
Depreciation and amortization(b)	157,925		145,554		150,902
Share-based compensation(c)	32,364		21,211		13,870
(Gain) loss on foreign currency and derivatives not designated as hedging instruments, net(d)	(1,552)		3,150		(58)
Acquisition and divestiture related charges, net(e)	937		1,398		(6,018)
Business optimization project expenses(f)	7,310		2,226		948
Plant closure expenses(g)	(585)		4,730		2,327
Impairment of investment in unconsolidated affiliate(h)	—		9,613		—
Loss on extinguishment of debt(i)	—		—		20,681
Professional services relating to EO sterilization facilities(j)	72,122		72,639		45,656
Illinois EO litigation settlement(k)	—		408,000		—
Georgia EO litigation settlement(l)	35,000		—		—
Accretion of asset retirement obligation(m)	2,413		2,194		2,252
COVID-19 expenses(n)	—		155		761
Consolidated income (loss) before taxes	$	106,027	$	(243,111)	$	175,716

(a)The year ended December 31, 2023 excludes $26.8 million of interest expense, net on Term Loan B attributable to the loan proceeds that were used to fund the $408.0 million Illinois EO litigation settlement. The year ended December 31, 2022 excludes a $1.7 million unrealized loss on interest rate derivatives not designated as hedging instruments.

(b)Includes depreciation of Co-60 held at gamma irradiation sites.

(c)Represents share-based compensation expense to employees and non-employee directors. See Note 16, “Share-Based Compensation” for further information.

(d)Represents the effects of (i) fluctuations in foreign currency exchange rates, (ii) non-cash mark-to-fair value of embedded derivatives relating to certain customer and supply contracts at Nordion, and (iii) unrealized gains and losses on interest rate derivatives not designated as hedging instruments.

(e)Represents (i) certain direct and incremental costs related to the acquisitions of RCA, the noncontrolling interests in our China subsidiaries, BioScience Labs in 2021, Iotron in July 2020, the first quarter 2021 gain on the mandatorily redeemable noncontrolling interest in Nelson Labs Fairfield, and certain related integration efforts as a result of those acquisitions, (ii) the earnings impact of fair value adjustments (excluding those recognized within amortization expense) resulting from the businesses acquired, (iii) transition services income and non-cash deferred lease income associated with the terms of the divestiture of the Medical Isotopes business in 2018, (iv) a $3.4 million gain recognized in the third quarter of 2021 related to the settlement of an insurance claim for Nordion that existed at the time of our acquisition of the business in 2014, and (v) a $5.1 million non-cash gain recognized in the fourth quarter of 2021 arising from the derecognition of an ARO liability no longer attributable to Nordion pursuant to the terms of the sale of the Medical Isotopes business in 2018.

(f)Represents professional fees, exit costs, severance and other payroll costs, and other costs associated with business optimization and cost savings projects relating to the integration of recent acquisitions, operating structure realignment and other process enhancement projects.

(g)Represents professional fees, severance and other payroll costs, and other costs including ongoing lease and utility expenses associated with the closure of the Willowbrook, Illinois facility. The year ended December 31, 2023 also includes a $1.0 million cancellation fee received from a tenant in connection with the termination of an office space lease at the Nordion facility.

(h)Represents an impairment charge on an equity method investment in a joint venture. Refer to Note 1, “Significant Accounting Policies” for further information.

(i)Represents expenses incurred in connection with the repricing of our Term Loan in January 2021 and full redemption of the First Lien Notes in August 2021, including a prepayment premium and accelerated amortization of prior debt issuance and discount costs.

(j)Represents litigation and other professional fees associated with our EO sterilization facilities. This includes $26.8 million of interest expense, net for the year ended December 31, 2023 associated with Term Loan B that was issued to finance the $408.0 million settlement of 880 pending and threatened EO claims against the Defendant Subsidiaries in Illinois under Settlement Agreements entered into on March 28, 2023. See Note 20, “Commitments and Contingencies”.

(k)Represents the cost to settle 880 pending and threatened EO claims against the Defendant Subsidiaries in Illinois pursuant to Settlement Agreements entered into on March 28, 2023. See Note 20, “Commitments and Contingencies”.

(l)Represents the cost to settle 79 pending EO claims against the Defendant Subsidiaries in Georgia under a Settlement Term Sheet entered into on December 21, 2023. See Note 20, “Commitments and Contingencies”.

(m)Represents non-cash accretion of asset retirement obligations related to Co-60 gamma and EO processing facilities, which are based on estimated site remediation costs for any future decommissioning of these facilities and are accreted over the life of the asset.

(n)Represents non-recurring costs associated with the COVID-19 pandemic, including incremental costs to implement workplace health and safety measures.

Geographic Information

Net revenues for geographic area are reported by the country’s origin of the revenues.


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
United States	$	590,967	$	579,018	$	527,907
Canada	192,050		188,741		177,875
Europe	187,542		166,025		161,810
Other	78,729		69,903		63,886
Total	$	1,049,288	$	1,003,687	$	931,478

The ‘Other’ category above is primarily comprised of net revenues from Asian and Latin American countries that individually represent 3% or less of our total net revenues.

Long-lived assets are based on physical locations and are comprised of the net book value of property, plant, and equipment.


(thousands of U.S. dollars)
As of December 31,	2023		2022
United States	$	494,793	$	413,887
Europe	170,669		143,809
Canada	181,628		140,761
Other	99,824		76,070
Total	$	946,914	$	774,527

The ‘Other’ category above is primarily comprised of long-lived assets in Asian and Latin American countries that individually represent 5% or less of our total long-lived assets.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-15

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-31

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (d)
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-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 32
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-40

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-Name Accounting Standards Codification
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-URI https://asc.fasb.org//280/tableOfContent

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 26
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-26

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-34

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Subparagraph (a)
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-URI https://asc.fasb.org//1943274/2147482810/280-10-50-21

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-21

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

+ Details

Employee Benefits - Reconciliation of Changes in Benefit Obligations and Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined benefit pension plan
Change in projected benefit obligation:
Projected benefit obligation, as of beginning of the year	$ 217,582	$ 296,712
Service cost	681	1,118
Interest cost	10,917	7,411	$ 6,516
Benefits paid	(12,305)	(12,207)
Actuarial loss (gain)	17,934	(59,378)
Foreign currency exchange rate changes	5,138	(16,074)
Projected benefit obligation, end of year	239,947	217,582	296,712
Change in fair value of plan assets:
Fair value of plan assets as of the beginning of the year	253,130	302,190
Actual return (loss) on plan assets	21,163	(20,038)
Benefits paid	(12,305)	(12,207)
Employer contributions	496	693
Employee contributions	156	149
Foreign currency exchange rate changes	5,784	(17,657)
Fair value of plan assets, end of year	268,424	253,130	302,190
Funded status at end of year	28,477	35,548
Accumulated benefit obligation, end of year	237,016	215,001
Other post-retirement benefits plans
Change in projected benefit obligation:
Projected benefit obligation, as of beginning of the year	8,391	11,942
Service cost	9	16	28
Interest cost	398	284	268
Benefits paid	(665)	(590)
Actuarial loss (gain)	509	(2,775)
Plan participant contributions	129	146
Foreign currency exchange rate changes	193	(632)
Projected benefit obligation, end of year	8,964	8,391	11,942
Change in fair value of plan assets:
Fair value of plan assets as of the beginning of the year	481	478
Benefits paid	(183)	(181)
Employer contributions	216	216
Foreign currency exchange rate changes	11	(32)
Fair value of plan assets, end of year	525	481	$ 478
Funded status at end of year	(8,439)	(7,910)
Accumulated benefit obligation, end of year	$ 8,943	$ 8,381

Earnings (Loss) Per Share

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Earnings (Loss) Per Share

Basic earnings (loss) per share represents the amount of income (loss) attributable to each common share outstanding. Diluted earnings (loss) per share represents the amount of income (loss) attributable to each common share outstanding adjusted for the effects of potentially dilutive common shares. Potentially dilutive common shares include stock options and other stock-based awards. In the periods where the effect would be antidilutive, potentially dilutive common shares are excluded from the calculation of diluted earnings per share.

In periods in which the Company has net income, earnings per share is calculated using the two-class method. This method is required as unvested restricted stock distributed in respect of pre-IPO Class B-1 and B-2 awards have the right to receive non-forfeitable dividends or dividend equivalents if the Company declares dividends on its common stock. Pursuant to the two-class method, earnings for each period are allocated on a pro-rata basis to common stockholders and unvested pre-IPO Class B-1 and B-2 restricted stock awards. Diluted earnings per share is computed using the more dilutive of (a) the two-class method, or (b) treasury stock method, as applicable, to the potentially dilutive instruments.

In periods in which the Company has a net loss, the two-class method is not applicable because the pre-IPO Class B-1 and B-2 restricted stock awards do not participate in losses.

Our basic and diluted earnings (loss) per common share are calculated as follows:


	Year Ended December 31,
in thousands of U.S. dollars and share amounts (except per share amounts)	2023		2022		2021
Earnings (loss):
Net income (loss)	$	51,376	$	(233,570)	$	117,121
Less: Net income attributable to noncontrolling interests	—		—		239
Less: Allocation to participating securities	287		—		1,524
Net income (loss) attributable to Sotera Health Company common stockholders	$	51,089	$	(233,570)	$	115,358
Weighted Average Common Shares:
Weighted-average common shares outstanding - basic	281,008		280,096		279,228
Dilutive effect of potential common shares(a)	2,213		—		154
Weighted-average common shares outstanding - diluted	283,222		280,096		279,382
Earnings (loss) per Common Share:
Net income (loss) per common share attributable to Sotera Health Company common stockholders - basic	$	0.18	$	(0.83)	$	0.41
Net income (loss) per common share attributable to Sotera Health Company common stockholders - diluted	0.18		(0.83)		0.41

(a)As the Company reported a net loss for the year ended December 31, 2022, the calculation of diluted weighted average common shares outstanding is not applicable for the year ended December 31, 2022 because the effect of including the potential common shares would be anti-dilutive.

Diluted earnings per shares does not consider the following potential common shares as the effect would be anti-dilutive:


	Year Ended December 31,
in thousands of share amounts	2023	2022	2021
RSUs	291	2,467	4
Stock options	4,108	5,990	2,403
Total anti-dilutive securities	4,399	8,457	2,407

Share-Based Compensation - Additional Information (Details) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 30,400	$ 19,100	$ 11,300
Cost not yet recognized	$ 2,100
2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	27.9
Number of shares available for grant (in shares)	17.6
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			2,600
Restricted Stock \| Pre-IPO B-1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Share-based compensation expense	$ 2,000	2,100
Cost not yet recognized	$ 2,100
Restricted Stock \| Pre-IPO B-1 \| Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Restricted Stock \| Pre-IPO B-1 \| Year Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Restricted Stock \| Pre-IPO B-1 \| Year Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Restricted Stock \| Pre-IPO B-1 \| Year Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Restricted Stock \| Pre-IPO B-1 \| Year Five
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20.00%
Restricted Stock \| Pre-IPO B-2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cost not yet recognized	$ 0
Restricted Stock \| Pre-IPO B-2 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash proceeds to sponsors, ratio to invested capital	250.00%
Investment, internal rate of return	20.00%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 14,400	7,800	5,100
Contractual term	10 years
Period for recognition	1 year 6 months
Cost not yet recognized	$ 18,300
Fair value of stock options vested	$ 10,600	4,400	5,000
Stock options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	2 years
Stock options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 16,000	11,300	6,200
Period for recognition	1 year 8 months 12 days
Cost not yet recognized	$ 22,400
Fair value of stock options vested	$ 14,100	$ 5,700	$ 5,100
RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Significant Accounting Policies - Noncontrolling Interest (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 subsidiary	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jul. 31, 2020
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Impairment of investment in unconsolidated affiliate			$ 0	$ 9,613	$ 0
Unnamed E-Beam Joint Venture \| Iotron
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Ownership percentage						60.00%
Auralux
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Investments, fair value	$ 0
Impairment of investment in unconsolidated affiliate	$ 9,600
China
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of subsidiaries with non-controlling interest \| subsidiary		2
China \| Subsidiary One
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percent of purchase of interest		15.00%
China \| Subsidiary Two
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Percent of purchase of interest		33.00%

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Income (Loss) Before Income Taxes

The geographic sources of income (loss) before income taxes were as follows:


(thousands of U.S. dollars)
Year ended December 31,	2023		2022		2021
U.S.	$	(100,635)	$	(418,308)	$	5,092
Foreign	206,662		175,197		170,624
Income (loss) before income taxes	$	106,027	$	(243,111)	$	175,716

Schedule of Total Provision (Benefit) for Income Taxes

Provision (benefit) for income taxes consisted of the following:


(thousands of U.S. dollars)
Year ended December 31,	2023		2022		2021
Current
Federal U.S.	$	(3,809)	$	12,841	$	13,915
State U.S.	924		5,082		3,220
Foreign	54,087		46,496		45,176
Total current provision	51,202		64,419		62,311
Deferred
Federal U.S.	6,933		(52,382)		(2,422)
State U.S.	(619)		(17,919)		391
Foreign	(2,865)		(3,659)		(1,685)
Total deferred provision (benefit)	3,449		(73,960)		(3,716)
Total provision (benefit) for income taxes	$	54,651	$	(9,541)	$	58,595

Schedule of Effective Income Tax Rate Reconciliation

The provision (benefit) for income taxes is reconciled with the U.S. federal statutory rate as follows:


(thousands of U.S. dollars)
Year ended December 31,	2023		2022		2021
Provision (benefit) computed at federal statutory rate	$	22,265	$	(51,053)	$	36,872
Increase (decrease) in taxes as a result of:
State taxes, net of federal benefit	(2,889)		(20,359)		1,013
Valuation allowance	19,494		53,860		8,455
Global intangible low-tax income (“GILTI”)	4,861		1,427		2,103
Nondeductible share-based compensation	3,192		2,510		1,512
Foreign tax rate differential	10,595		8,335		8,005
Impact of rate changes on deferred tax balances	(92)		(1,184)		2,612
Tax holiday	(1,082)		(605)		(706)
Audit settlement	739		276		276
Tax credits	—		(172)		(248)
Other	(2,432)		(2,576)		(1,299)
Total provision (benefit) for income taxes	$	54,651	$	(9,541)	$	58,595

Schedule of Deferred Tax Assets and Liabilities

The components of the tax effects of temporary differences and carryforwards that gave rise to significant portions of the deferred tax assets and liabilities are as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Net operating loss carryforwards	$	71,552	$	9,286
Net capital loss carryforwards	4,686		4,666
Reserves and accruals	26,591		121,685
Employee benefits and compensation	8,519		6,610
Asset retirement obligations	11,140		10,649
Lease liability	8,733		9,506
Disallowed interest carryforward	129,320		89,682
Other	10,806		6,561
Deferred tax assets before valuation allowance	271,347		258,645
Valuation allowance	(125,435)		(105,600)
Net deferred tax assets	145,912		153,045

Depreciation and amortization	(195,450)		(199,670)

Other	(9,923)		(17,298)
Total deferred tax liabilities	(205,373)		(216,968)
Net deferred tax liabilities	$	(59,461)	$	(63,923)
Noncurrent net deferred tax assets	$	4,993	$	4,101
Noncurrent net deferred tax liabilities	(64,454)		(68,024)
Noncurrent net deferred tax liabilities	$	(59,461)	$	(63,923)

Summary of Income Tax Contingencies

The Company’s unrecognized income tax benefits were as follows:


(thousands of U.S. dollars)
For the period from January 1 – December 31,	2023		2022
Gross unrecognized tax benefits, beginning of year	$	—	$	116
Additions related to current year	—		—

Reductions related to prior years	—		(116)
Settlements	—		—

Gross unrecognized tax benefits, end of period	$	—	$	—

Inventories (Tables)

12 Months Ended

Dec. 31, 2023

Inventory Disclosure [Abstract]

Schedule of Inventories

Inventories consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Raw materials and supplies	$	43,411	$	36,402
Work-in-process	471		584
Finished goods	4,670		276
	48,552		37,262
Reserve for excess and obsolete inventory	(236)		(117)
Inventories, net	$	48,316	$	37,145

Leases - Costs (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating lease costs	$ 13,920	$ 15,122	$ 15,433
Finance lease costs:
Amortization of right of use assets	8,152	6,368	3,018
Interest on lease liabilities	4,394	3,454	2,506
Total finance lease costs	12,546	9,822	5,524
Total lease costs	26,466	24,944	20,957
Short-term lease costs	$ 1,400	$ 1,300	$ 900

Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2023

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

Financial information for each of our segments is presented in the following table:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Segment revenues(a)
Sterigenics	$	667,130	$	626,646	$	571,829
Nordion	160,459		153,639		140,507
Nelson Labs	221,699		223,402		219,142
Total net revenues	$	1,049,288	$	1,003,687	$	931,478
Segment income(b)
Sterigenics	$	362,212	$	339,144	$	310,470
Nordion	96,678		89,477		82,673
Nelson Labs	69,139		77,628		88,086
Total segment income	$	528,029	$	506,249	$	481,229

(b)Segment income is only provided on a net basis to the chief operating decision maker and is reported net of intersegment profits.

Capital expenditures by segment for the years ended December 31, 2023, 2022 and 2021 were as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Sterigenics	$	163,043	$	144,027	$	73,753
Nordion	38,351		26,575		21,292
Nelson Labs	13,581		11,776		7,117
Total capital expenditures	$	214,975	$	182,378	$	102,162

Schedule of Reconciliation of Operating Profit (Loss) from Segments to Consolidated

A reconciliation of segment income to consolidated income (loss) before taxes is as follows:


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
Segment income	$	528,029	$	506,249	$	481,229
Less adjustments:
Interest expense, net(a)	116,068		78,490		74,192
Depreciation and amortization(b)	157,925		145,554		150,902
Share-based compensation(c)	32,364		21,211		13,870
(Gain) loss on foreign currency and derivatives not designated as hedging instruments, net(d)	(1,552)		3,150		(58)
Acquisition and divestiture related charges, net(e)	937		1,398		(6,018)
Business optimization project expenses(f)	7,310		2,226		948
Plant closure expenses(g)	(585)		4,730		2,327
Impairment of investment in unconsolidated affiliate(h)	—		9,613		—
Loss on extinguishment of debt(i)	—		—		20,681
Professional services relating to EO sterilization facilities(j)	72,122		72,639		45,656
Illinois EO litigation settlement(k)	—		408,000		—
Georgia EO litigation settlement(l)	35,000		—		—
Accretion of asset retirement obligation(m)	2,413		2,194		2,252
COVID-19 expenses(n)	—		155		761
Consolidated income (loss) before taxes	$	106,027	$	(243,111)	$	175,716

(b)Includes depreciation of Co-60 held at gamma irradiation sites.

(c)Represents share-based compensation expense to employees and non-employee directors. See Note 16, “Share-Based Compensation” for further information.

(h)Represents an impairment charge on an equity method investment in a joint venture. Refer to Note 1, “Significant Accounting Policies” for further information.

(n)Represents non-recurring costs associated with the COVID-19 pandemic, including incremental costs to implement workplace health and safety measures.

Schedule f Revenue from External Customers by Geographic Areas

Net revenues for geographic area are reported by the country’s origin of the revenues.


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
United States	$	590,967	$	579,018	$	527,907
Canada	192,050		188,741		177,875
Europe	187,542		166,025		161,810
Other	78,729		69,903		63,886
Total	$	1,049,288	$	1,003,687	$	931,478

Schedule of Long-lived Assets by Geographic Areas

Long-lived assets are based on physical locations and are comprised of the net book value of property, plant, and equipment.


(thousands of U.S. dollars)
As of December 31,	2023		2022
United States	$	494,793	$	413,887
Europe	170,669		143,809
Canada	181,628		140,761
Other	99,824		76,070
Total	$	946,914	$	774,527

Leases

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Leases

We lease certain facilities and equipment under various non-cancelable leases. Most of our real property leases provide for renewal periods and rent escalations and stipulate that we pay taxes, maintenance, and certain other operating expenses applicable to the leased premises.

The components of lease expense were as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Operating lease costs (a)	$	13,920	$	15,122	$	15,433
Finance lease costs:
Amortization of right of use assets	8,152		6,368		3,018
Interest on lease liabilities	4,394		3,454		2,506
Total finance lease costs	12,546		9,822		5,524
Total lease costs	$	26,466	$	24,944	$	20,957

(a)Includes $1.4 million, $1.3 million, and $0.9 million of short-term lease costs in the year ended December 31, 2023, 2022, and 2021, respectively.

Lease terms and discount rates were as follows:


	Year Ended December 31,
	2023		2022
Weighted average remaining lease term:
Operating leases	5.7 years		4.5 years
Finance leases	14.0 years		14.0 years
Weighted average discount rate:
Operating leases	5.92	%	5.88	%
Finance leases	5.76	%	5.48	%

Supplemental cash flow information related to leases was as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	10,067	$	11,112	$	12,494
Operating cash flow for finance leases	3,988		2,932		2,042
Finance cash flows for finance leases	1,823		1,066		901

Supplemental non-cash information was as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Lease liabilities arising from obtaining right-of-use assets:
Operating leases	$	4,559	$	1,338	$	8,742
Finance leases	14,770		18,286		10,995

Maturities of lease liabilities as of December 31, 2023 are as follows:


(thousands of U.S. dollars)	Operating Leases		Finance Leases		Total
2024	$	7,357	$	12,579	$	19,936
2025	5,505		5,767		11,272
2026	5,077		5,737		10,814
2027	3,999		5,893		9,892
2028	2,926		6,063		8,989
2029 and Thereafter	6,165		74,337		80,502
Total lease payments	31,029		110,376		141,405
Less imputed interest	(5,008)		(37,812)		(42,820)
Total lease liabilities	$	26,021	$	72,564	$	98,585

Leases

The components of lease expense were as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Operating lease costs (a)	$	13,920	$	15,122	$	15,433
Finance lease costs:
Amortization of right of use assets	8,152		6,368		3,018
Interest on lease liabilities	4,394		3,454		2,506
Total finance lease costs	12,546		9,822		5,524
Total lease costs	$	26,466	$	24,944	$	20,957

(a)Includes $1.4 million, $1.3 million, and $0.9 million of short-term lease costs in the year ended December 31, 2023, 2022, and 2021, respectively.

Lease terms and discount rates were as follows:


	Year Ended December 31,
	2023		2022
Weighted average remaining lease term:
Operating leases	5.7 years		4.5 years
Finance leases	14.0 years		14.0 years
Weighted average discount rate:
Operating leases	5.92	%	5.88	%
Finance leases	5.76	%	5.48	%

Supplemental cash flow information related to leases was as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	10,067	$	11,112	$	12,494
Operating cash flow for finance leases	3,988		2,932		2,042
Finance cash flows for finance leases	1,823		1,066		901

Supplemental non-cash information was as follows:


	Year Ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Lease liabilities arising from obtaining right-of-use assets:
Operating leases	$	4,559	$	1,338	$	8,742
Finance leases	14,770		18,286		10,995

Maturities of lease liabilities as of December 31, 2023 are as follows:


(thousands of U.S. dollars)	Operating Leases		Finance Leases		Total
2024	$	7,357	$	12,579	$	19,936
2025	5,505		5,767		11,272
2026	5,077		5,737		10,814
2027	3,999		5,893		9,892
2028	2,926		6,063		8,989
2029 and Thereafter	6,165		74,337		80,502
Total lease payments	31,029		110,376		141,405
Less imputed interest	(5,008)		(37,812)		(42,820)
Total lease liabilities	$	26,021	$	72,564	$	98,585

Employee Benefits - Reconciliation of Funded Status (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 239,947	$ 217,582
Fair value of plan assets	268,424	253,130
Plan assets greater than projected benefit obligation (noncurrent assets)	28,477	35,548
Unrecognized net actuarial loss (gain)	11,429	(1,649)
Other post-retirement benefits plans
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	8,964	8,391
Fair value of plan assets	525	481
Plan assets greater than projected benefit obligation (noncurrent assets)	(8,439)	(7,910)
Unrecognized net actuarial loss (gain)	$ 2,074	$ 2,732

Asset Retirement Obligations (“ARO”) (Tables)

12 Months Ended

Dec. 31, 2023

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Asset Retirement Obligations

The following table describes changes to our ARO liability during the years presented:


(thousands of U.S. dollars)
For the Year Ended	2023		2022
ARO – beginning of period	$	45,482	$	42,452
Liabilities settled	(2,896)		(497)
Changes in estimates	2,133		2,593
Accretion expense	2,413		2,194
Foreign currency exchange and other	812		(1,260)
ARO – end of period	47,944		45,482
Less current portion of ARO	—		2,896
Noncurrent ARO – end of period	$	47,944	$	42,586

Employee Benefits - A One-Percentage Point Change in Assumed Health Care Cost Trend Rates (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Change in net periodic benefit cost, 1% Increase	$ 25
Change in net periodic benefit cost, 1% Decrease	(22)
Change in projected benefit obligation, 1% Increase	596
Change in projected benefit obligation, 1% Decrease	$ (500)

Segment and Geographic Information - Segment Operating Results (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net revenues	$ 1,049,288	$ 1,003,687	$ 931,478
Total capital expenditures	214,975	182,378	102,162
Sterigenics
Segment Reporting Information [Line Items]
Net revenues	667,130	626,646	571,829
Total capital expenditures	163,043	144,027	73,753
Nordion
Segment Reporting Information [Line Items]
Net revenues	160,459	153,639	140,507
Total capital expenditures	38,351	26,575	21,292
Nelson Labs
Segment Reporting Information [Line Items]
Net revenues	221,699	223,402	219,142
Total capital expenditures	13,581	11,776	7,117
Operating Segments
Segment Reporting Information [Line Items]
Net revenues	1,049,288	1,003,687	931,478
Segment income	528,029	506,249	481,229
Operating Segments \| Sterigenics
Segment Reporting Information [Line Items]
Net revenues	667,130	626,646	571,829
Segment income	362,212	339,144	310,470
Operating Segments \| Nordion
Segment Reporting Information [Line Items]
Net revenues	160,459	153,639	140,507
Segment income	96,678	89,477	82,673
Operating Segments \| Nelson Labs
Segment Reporting Information [Line Items]
Net revenues	221,699	223,402	219,142
Segment income	69,139	77,628	88,086
Intersegment
Segment Reporting Information [Line Items]
Net revenues	$ (43,900)	$ (52,400)	$ (34,100)

- Definition

+ References

+ Details

Asset Retirement Obligations (“ARO”) - Changes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO – beginning of period	$ 45,482	$ 42,452
Liabilities settled	(2,896)	(497)
Changes in estimates	2,133	2,593
Accretion expense	2,413	2,194	$ 2,252
Foreign currency exchange and other	812	(1,260)
ARO – end of period	47,944	45,482	$ 42,452
Less current portion of ARO	0	2,896
Noncurrent ARO – end of period	$ 47,944	$ 42,586

Financial Instruments and Financial Risk

12 Months Ended

Dec. 31, 2023

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Financial Instruments and Financial Risk

Derivative Instruments

We do not use derivatives for trading or speculative purposes and are not a party to leveraged derivatives.

Derivatives Designated in Hedge Relationships

From time to time, the Company utilizes interest rate derivatives designated in hedge relationships to manage interest rate risk associated with our variable rate borrowings. These instruments are measured at fair value with changes in fair value recorded as a component of “Accumulated other comprehensive income (loss)” on our Consolidated Balance Sheets.

In March 2023, we entered into an interest rate swap agreement with a notional amount of $400.0 million. The interest rate swap was effective on August 23, 2023 and expires on August 23, 2025. We have designated the interest rate swap as a cash flow hedge designed to hedge the variability of cash flows attributable to changes in the SOFR benchmark interest rate of our 2023 Term Loan (or any successor thereto). We receive interest at the one-month Term SOFR rate and pay a fixed interest rate under the terms of the swap agreement.

In May 2022, we entered into two interest rate cap agreements with a combined notional amount of $1,000.0 million for a total option premium of $4.1 million. The interest rate caps were effective on July 31, 2023 and expire on July 31, 2024. We have designated these interest rate caps as cash flow hedges designed to hedge the variability of cash flows attributable to changes in the benchmark interest rate of our Term Loan (or any successor thereto). Under the current terms of the loan agreement, the benchmark interest rate index transitioned from LIBOR to the Term SOFR on June 30, 2023. Accordingly, the interest rate cap agreements hedge the variability of cash flows attributable to changes in SOFR by limiting our cash flow exposure related to Term SOFR under a portion of our variable rate borrowings to 3.5%.

In October 2021, we entered into two interest rate cap agreements with a combined notional amount of $1,000.0 million for a total option premium of $1.8 million. Both interest rate caps were effective on December 31, 2022 and expired on July 31, 2023. These interest rate caps are designated as cash flow hedges and were designed to hedge the variability of cash flows attributable to changes in LIBOR (or its successor), the benchmark interest rate being hedged, by limiting our cash flow exposure related to the LIBOR base rate under a portion of our variable rate borrowings to 1.0%.

Derivatives Not Designated in Hedge Relationships

Additionally, from time to time, the Company enters into interest rate derivatives to manage economic risks associated with our variable rate borrowings that are not designated in hedge relationships. These instruments are recorded at fair value on the Consolidated Balance Sheets, with any changes in the value being recorded in “Interest expense, net” in the Consolidated Statements of Operations and Comprehensive Income (Loss).

The Company also routinely enters into foreign currency forward contracts to manage foreign currency exchange rate risk of our intercompany loans in certain of our international subsidiaries and non-functional currency assets and liabilities. The foreign currency forward contracts expire on a monthly basis.

Embedded Derivatives

We have embedded derivatives in certain of our customer and supply contracts as a result of the currency of the contract being different from the functional currency of the parties involved. Changes in the fair value of the embedded derivatives are recognized in “Other income, net” in the Consolidated Statements of Operations and Comprehensive Income (Loss).

The following table provides a summary of the notional and fair values of our derivative instruments:


	December 31, 2023						December 31, 2022
(in U.S. dollars; notional in millions, fair value in thousands)			Fair Value						Fair Value
	Notional Amount		Derivative Assets		Derivative Liabilities		Notional Amount		Derivative Assets		Derivative Liabilities
Derivatives designated as hedging instruments
Interest rate caps	$	1,000.0	$	8,763	$	—	$	2,000.0	$	34,764	$	—
Interest rate swaps	400.0		1,487		—		—		—		—
Derivatives not designated as hedging instruments
Foreign currency forward contracts	171.0		149		9		151.5		—		272
Embedded derivatives(a)	150.1		1,225		405		179.9		2,721		3,508
Total	$	1,721.1	$	11,624	$	414	$	2,331.4	$	37,485	$	3,780

(a)Represents the total notional amounts for certain of the Company’s supply and sales contracts accounted for as embedded derivatives.

Embedded derivatives assets and foreign currency forward contracts are included in “Prepaid expenses and other current assets” and “Accrued Liabilities” on our Consolidated Balance Sheets depending upon their position at period end. Interest rate swaps and interest rate caps are included in “Other assets” and “Noncurrent liabilities”, respectively, on the Consolidated Balance Sheets depending upon their position at period end.

The following tables summarize the activities of our derivative instruments for the periods presented, and the line item they are recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss):


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
Unrealized loss (gain) on interest rate derivatives recorded in interest expense, net	$	—	$	—	$	(1,185)
Realized (gain) loss on interest rate derivatives recorded in interest expense, net(a)	(33,094)		(12,226)		—
Unrealized (gain) loss on embedded derivatives recorded in other (income)/ expense, net	(1,637)		1,324		(1,195)
Realized (gain) loss on foreign currency forward contracts recorded in foreign exchange (gain) loss	(2,025)		3,931		(1,900)
Unrealized (gain) loss on foreign currency forward contracts recorded in foreign exchange (gain) loss	(412)		272		—

(a) For the years ended December 31, 2023 and December 31, 2022, amounts represent periodic settlement of interest rate caps and swaps.

We expect to reclassify approximately $8.7 million of after-tax net gains on derivative instruments from accumulated other comprehensive income (loss) to income during the next 12 months associated with our cash flow hedges. Refer to Note 14, “Other Comprehensive Income (Loss)” for unrealized gains on interest rate derivatives, net of applicable tax, recorded in other comprehensive income (loss) and amounts reclassified from accumulated other comprehensive income to interest expense, net of applicable tax, during the years ended December 31, 2023 and December 31, 2022.

Credit Risk

Certain of our financial assets, including cash and cash equivalents, are exposed to credit risk.

We are also exposed, in our normal course of business, to credit risk from our customers. As of December 31, 2023 and 2022, accounts receivable was net of an allowance for uncollectible accounts of $4.7 million and $1.9 million, respectively.

Credit risk on financial instruments arises from the potential for counterparties to default on their contractual obligations to us. We are exposed to credit risk in the event of non-performance, but do not anticipate non-performance by any of the counterparties to our financial instruments. We limit our credit risk by dealing with counterparties that are considered to be of high credit quality. In the event of non-performance by counterparties, the carrying value of our financial instruments represents the maximum amount of loss that would be incurred.

Our credit team evaluates and regularly monitors changes in the credit risk of our customers. We routinely assess the collectability of accounts receivable and maintain an adequate allowance for uncollectible accounts to address potential credit losses. The process includes a review of customer financial information and credit ratings, current market conditions as well as the expected future economic conditions that may impact the collection of trade receivables. We regularly review our customers’ past due amounts through an analysis of aged accounts receivables, specific customer past due aging amounts, and the history of trade receivables written off. Upon concluding that a receivable balance is not collectible, the balance is written off against the allowance for uncollectible accounts.

Fair Value Hierarchy

The fair value of our financial instruments is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The valuation techniques we would use to determine such fair values are described as follows: Level 1—fair values determined by inputs utilizing quoted prices in active markets for identical assets or liabilities; Level 2—fair values based on observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable; Level 3—fair values determined by unobservable inputs reflecting our own assumptions, consistent with reasonably available assumptions made by other market participants.

The following table discloses the fair value our financial assets and liabilities:


As of December 31, 2023			Fair Value
(thousands of U.S. dollars)	Carrying Amount		Level 1		Level 2		Level 3
Derivatives designated as hedging instruments(a)
Interest rate caps	$	8,763	$	—	$	8,763	$	—
Interest rate swaps	1,487		—		1,487		—
Derivatives not designated as hedging instruments(b)
Foreign currency forward contract assets	149		—		149		—
Foreign currency forward contract liabilities	9		—		9		—
Embedded derivative assets	1,225		—		1,225		—
Embedded derivative liabilities	405		—		405		—
Current portion of long-term debt(c)
Term loan B, due 2026	4,797		—		5,000		—
Long-Term Debt(c)
Term loan, due 2026	1,751,197		—		1,758,163		—
Term loan B, due 2026	472,477		—		492,500		—
Finance Lease Obligations (with current portion)(d)	72,564		—		72,564		—


As of December 31, 2022			Fair Value
(thousands of U.S. dollars)	Carrying Amount		Level 1		Level 2		Level 3
Derivatives designated as hedging instruments(a)
Interest rate caps	$	34,764	—		34,764		—
Derivatives not designated as hedging instruments(b)
Foreign currency forward contracts	272		—		272		—
Interest rate caps	2,721		$	—	$	2,721	$	—
Embedded derivative liabilities	3,508		—		3,508		—
Current portion of long-term debt(e)
Revolving credit facility	196,672		—		196,672		—
Other long-term debt	447		—		447		—
Long-Term Debt(c)
Term loan, due 2026	1,747,115		—		1,626,460		—
Finance Lease Obligations (with current portion)(d)	58,677		—		58,677		—

(a)Derivatives designated as hedging instruments are measured at fair value with changes in fair value recorded as a component of accumulated other comprehensive income (loss). Interest rate caps and swaps are valued using pricing models that incorporate observable market inputs including interest rate curves and yield curves. Additional information is provided in Note 1, “Significant Accounting Policies”.

(b)Derivatives that are not designated as hedging instruments are measured at fair value with gains or losses recognized immediately in the Consolidated Statements of Operations and Comprehensive Income (Loss). Refer also to Note 1, “Significant Accounting Policies”. Embedded derivatives are valued using internally developed models that rely on observable market inputs, including foreign currency forward curves. Foreign currency forward contracts are valued by reference to changes in foreign currency exchange rate over the life of the contract. Interest rate caps are valued using pricing models that incorporate observable market inputs including interest rate and yield curves.

(c)Carrying amounts of current portion of long-term debt and long-term debt instruments are reported net of discounts and debt issuance costs. The estimated fair value of these instruments is based upon quoted prices for the term loans due in 2026 in inactive markets as provided by an independent fixed income security pricing service.

(d)Refer to Note 18, “Leases”. Fair value approximates carrying value.

(e)Carrying amounts of current portion of long-term debt for the year ended December 31, 2022 are reported net of discounts and debt issuance costs. Fair value approximates carrying value for the year ended December 31, 2022.

Goodwill and Other Intangible Assets - Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2023
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 959,264	$ 967,350
Accumulated Amortization	570,626	655,562
Gross Carrying Amount	102,627	104,530
Total	1,061,891	1,071,880
Regulatory licenses and other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 76,978	78,684
Renewal term	10 years
Trade names / trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 25,649	25,846
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	652,811	657,673
Accumulated Amortization	422,277	485,188
Proprietary technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	86,054	84,918
Accumulated Amortization	50,952	56,846
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,553	2,567
Accumulated Amortization	701	1,207
Land-use rights
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,986	8,756
Accumulated Amortization	1,683	1,855
Sealed source and supply agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	204,391	208,919
Accumulated Amortization	93,034	107,561
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,469	4,517
Accumulated Amortization	$ 1,979	$ 2,905

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 350,238	$ 586,096	$ 454,574
Other comprehensive income (loss) before reclassifications	36,307	(23,074)	9,231
Amounts reclassified from accumulated other comprehensive income (loss)	(22,336)	(13)	1,045
Ending Balance	443,734	350,238	586,096
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(106,653)	(83,566)	(93,842)
Net current-period other comprehensive income (loss)	13,971	(23,087)	10,276
Ending Balance	(92,682)	(106,653)	(83,566)
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3,209	(17,581)	(44,143)
Other comprehensive income (loss) before reclassifications	(10,308)	20,803	25,517
Amounts reclassified from accumulated other comprehensive income (loss)	(198)	(13)	1,045
Net current-period other comprehensive income (loss)	(10,506)	20,790	26,562
Ending Balance	(7,297)	3,209	(17,581)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(131,205)	(66,389)	(49,699)
Other comprehensive income (loss) before reclassifications	40,174	(64,816)	(16,690)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0
Net current-period other comprehensive income (loss)	40,174	(64,816)	(16,690)
Ending Balance	(91,031)	(131,205)	(66,389)
Interest Rate Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	21,343	404	0
Other comprehensive income (loss) before reclassifications	6,441	20,939	404
Amounts reclassified from accumulated other comprehensive income (loss)	(22,138)	0	0
Net current-period other comprehensive income (loss)	(15,697)	20,939	404
Ending Balance	$ 5,646	$ 21,343	$ 404

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

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- Definition

Amount of equity (deficit) attributable to parent and noncontrolling interest. Excludes temporary equity.

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-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-3

Reference 37: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
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Reference 38: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
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Reference 39: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 40: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

Employee Benefits - Expected Future Benefit Payments (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Defined benefit pension plan
Estimated Future Benefit Payments
2024	$ 14,066
2025	14,363
2026	14,651
2027	14,774
2028	14,911
2029 - 2033	75,755
Total	148,520
Other post-retirement benefits plans
Estimated Future Benefit Payments
2024	538
2025	549
2026	548
2027	575
2028	512
2029 - 2033	2,643
Total	$ 5,365

Share-Based Compensation - Pre-IPO Awards Assumptions (Details) - Pre-IPO Awards	12 Months Ended
	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.60%
Expected volatility	50.00%
Expected term (years)	7 months 6 days

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2023
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Asset Retirement Obligations (“ARO”)

12 Months Ended

Dec. 31, 2023

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations (“ARO”)

Our ARO represent the present value of future remediation costs and an increase in the carrying amounts of the related assets in property, plant and equipment in the Consolidated Balance Sheets. The capitalized future site remediation costs are depreciated and the ARO are accreted over the life of the related assets which is included in depreciation and amortization expense, respectively.

The fair value of the ARO is determined based on estimates requiring management judgment. Key assumptions include the timing and estimated decommissioning costs of the remediation activities and credit adjusted risk free interest rates. Changes in the assumptions based on future information may result in adjustments to the estimated obligations over time. No market risk premium has been included in the calculation for the ARO since no reliable estimate can be made by the Company. Any difference between costs incurred upon settlement of an ARO and the liability recognized for the estimated cost of asset retirements will be recognized as a gain or loss in our current period operating results.

Each year, we review decommissioning costs and consider changes in marketplace rates. The following table describes changes to our ARO liability during the years presented:


(thousands of U.S. dollars)
For the Year Ended	2023		2022
ARO – beginning of period	$	45,482	$	42,452
Liabilities settled	(2,896)		(497)
Changes in estimates	2,133		2,593
Accretion expense	2,413		2,194
Foreign currency exchange and other	812		(1,260)
ARO – end of period	47,944		45,482
Less current portion of ARO	—		2,896
Noncurrent ARO – end of period	$	47,944	$	42,586

We recorded depreciation expense on the ARO of $0.4 million, $0.3 million and $0.4 million, for the years ended December 31, 2023, 2022, and 2021 respectively.

We are obligated to provide financial assurance to local and state licensing authorities for possible future decommissioning costs associated with the various facilities that hold Co-60. At December 31, 2023 and 2022, $48.2 million and $54.1 million, respectively, of the standby letters of credit referenced above and surety bonds were outstanding in favor of the various local and state licensing authorities in the event we defaulted on our decommissioning obligation.

Other Comprehensive Income (Loss)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Other Comprehensive Income (Loss)

Amounts in accumulated other comprehensive income (loss) are presented net of the related tax. Foreign currency translation is not adjusted for income taxes.

Changes in our accumulated other comprehensive income (loss) balances, net of applicable tax, were as follows:


(thousands of U.S. dollars)	Defined Benefit Plans			Foreign Currency Translation		Interest Rate Derivatives			Total
Beginning balance – January 1, 2021	$	(44,143)		$	(49,699)	$	—		$	(93,842)
Other comprehensive income (loss) before reclassifications	25,517			(16,690)		404			9,231
Amounts reclassified from accumulated other comprehensive income (loss)	1,045		(a)	—		—		(b)	1,045
Net current-period other comprehensive income (loss)	26,562			(16,690)		404			10,276
Ending balance – December 31, 2021	$	(17,581)		$	(66,389)	$	404		$	(83,566)

Beginning balance – January 1, 2022	$	(17,581)		$	(66,389)	$	404		$	(83,566)
Other comprehensive income (loss) before reclassifications	20,803			(64,816)		20,939			(23,074)
Amounts reclassified from accumulated other comprehensive income (loss)	(13)		(a)	—		—			(13)
Net current-period other comprehensive income (loss)	20,790			(64,816)		20,939			(23,087)
Ending balance – December 31, 2022	$	3,209		$	(131,205)	$	21,343		$	(106,653)

Beginning balance – January 1, 2023	$	3,209		$	(131,205)	$	21,343		$	(106,653)
Other comprehensive income (loss) before reclassifications	(10,308)			40,174		6,441			36,307
Amounts reclassified from accumulated other comprehensive income (loss)	(198)		(a)	—		(22,138)			(22,336)
Net current-period other comprehensive income (loss)	(10,506)			40,174		(15,697)			13,971
Ending balance – December 31, 2023	$	(7,297)		$	(91,031)	$	5,646		$	(92,682)

(a)For defined benefit pension plans, amounts reclassified from accumulated other comprehensive income (loss) are recorded to “Other income, net” within the Consolidated Statements of Operations and Comprehensive Income (Loss).

(b)For interest rate derivatives, amounts reclassified from accumulated other comprehensive income (loss) are recorded to “Interest expense, net” within the Consolidated Statements of Operations and Comprehensive Income (Loss)

Leases - Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Cash Flows (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Leases [Abstract]
Operating cash flows for operating leases	$ 10,067	$ 11,112	$ 12,494
Operating cash flow for finance leases	3,988	2,932	2,042
Finance cash flows for finance leases	$ 1,823	$ 1,066	$ 901

Employee Benefits - Amounts in Accumulated Other Comprehensive Income Loss (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss amount expected to be reclassified in the next twelve month in accumulated other comprehensive income	$ 0
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain	11,429,000	$ (1,649,000)
Deferred income taxes	(2,919,000)	370,000
Accumulated other comprehensive income – net of tax	8,510,000	(1,279,000)
Other post-retirement benefits plans
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain	(2,074,000)	(2,732,000)
Deferred income taxes	585,000	699,000
Accumulated other comprehensive income – net of tax	$ (1,489,000)	$ (2,033,000)

Share-Based Compensation - Stock Options Activities (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares shares
Number of Shares
Beginning balance (in shares) \| shares	5,990,470
Granted (in shares) \| shares	1,100,329
Forfeited (in shares) \| shares	(118,138)
Exercised (in shares) \| shares	0
Ending balance (in shares) \| shares	6,972,661
Weighted- average Exercise Price
Beginning balance (in shares) \| $ / shares	$ 14.84
Granted (in dollars per share) \| $ / shares	17.52
Forfeited (in dollars per share) \| $ / shares	20.43
Exercised (in dollars per share) \| $ / shares	0
Ending balance (in shares) \| $ / shares	$ 15.17
Outstanding at the end of the year, Remaining Contractual Life	8 years 2 months 12 days
Outstanding at the end of the year, Aggregate Intrinsic Value \| $	$ 28,500
Exercisable at the end of the year, Number of Shares (in shares) \| shares	2,828,011
Exercisable at the end of the year, Weighted-average Exercise Price (in dollars per share) \| $ / shares	$ 17.08
Exercisable at the end of the year, Remaining Contractual Life	7 years 8 months 12 days
Exercisable at the end of the year, Aggregate Intrinsic Value \| $
Unvested at the end of the year, Number of Shares (in shares) \| shares	4,144,650
Unvested at the end of the year, Weighted-average Exercise Price (in dollars per share) \| $ / shares	$ 13.87
Unvested at the end of the year, Remaining Contractual Life	8 years 7 months 6 days
Unvested at the end of the year, Aggregate Intrinsic Value \| $

Employee Benefits - Pension Plan Weighted Average Asset Allocations (Details) - Defined benefit pension plan	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target	100.00%
Defined benefit plan securities	100.00%	100.00%
Cash
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target	0.00%
Defined benefit plan securities	0.70%	0.40%
Fixed income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target	54.00%
Defined benefit plan securities	43.70%	43.10%
Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target	27.00%
Defined benefit plan securities	34.00%	33.40%
Hedge funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target	19.00%
Defined benefit plan securities	21.60%	23.10%

Share-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Share-Based Compensation

Pre-IPO Awards

Prior to our IPO, the Company’s equity-based awards issued to service providers (including directors and employees) included partnership interests in Topco Parent (Class B-1 or B-2 Units) which vested based on either time or the achievement of certain performance and market conditions (the “pre-IPO awards”). These equity-based awards represented an interest in our former parent and were granted in respect of services provided to the Company and its subsidiaries. In connection with the IPO, our

former parent made in-kind distributions of shares of our common stock to its limited partners as described in Note 15, “Stockholders' Equity”. At the time of the IPO, there were fewer than 60 individuals who received shares in the in-kind distribution; while this distribution represented a modification to the existing awards, there was no associated change in compensation expense because the fair value of the distributed shares immediately before and after the distribution was the same.

Restricted stock distributed in respect of pre-IPO Class B-1 time vesting units vests on a daily basis pro rata over a five-year vesting period (20% per year) beginning on the original vesting commencement date of the corresponding Class B-1 time vesting units, subject to the grantee’s continued services through each vesting date. Upon the occurrence of a change in control of the Company, all then outstanding unvested shares of our common stock distributed in respect of Class B-1 Units will vest as of the date of consummation of such change in control, subject to the grantee’s continued services through the consummation of the change in control.

Restricted stock distributed in respect of pre-IPO Class B-2 Units (which were considered performance vesting units) are scheduled to vest only upon satisfaction of certain thresholds. These units generally vest as of the first date on which (i) our Sponsors have received actual cash proceeds in an amount equal to or in excess of at least two and one-half times their invested capital in Sotera Health Topco Parent, L.P. (of which the Company was a direct wholly-owned subsidiary prior to the IPO) and (ii) the Sponsors’ internal rate of return exceeds 20%, subject to such grantee’s continued services through such date. In the event of a change in control of the Company, any outstanding shares of our common stock distributed in respect of Class B-2 Units that remain unvested immediately following the consummation of such a change in control of the Company shall be immediately canceled and forfeited without compensation. Stock based compensation expense attributed to the pre-IPO Class B-2 awards was recorded in the fourth quarter of 2020 as the related performance conditions were considered probable of achievement and the implied service conditions were met. As of December 31, 2023, these awards remain unvested.

We recognized $2.0 million, $2.1 million and $2.6 million of share-based compensation expense related to pre-IPO Class B-1 Units for the years ended December 31, 2023, 2022, and 2021, respectively.

The assumptions used to calculate the fair value of the pre-IPO awards were as follows:


	2020
Risk-free interest rate	1.6	%
Expected volatility	50	%
Expected dividends	None
Expected time until exercise (years)	0.6

These awards were no longer issued after the IPO in November 2020.

A summary of the activity for the years ended December 31, 2023, 2022 and 2021 related to the restricted stock distributed to the Company service providers in respect of the pre-IPO awards (Class B-1 and B-2) is presented below:


	Restricted Stock - Pre-IPO B-1	Restricted Stock - Pre-IPO B-2
At January 1, 2021	2,201,239	2,323,333
Forfeited	(72,467)	(299,374)
Vested	(922,683)	—
At December 31, 2021	1,206,089	2,023,959
Forfeited	(54,333)	(925,544)
Vested	(435,665)	—
At December 31, 2022	716,091	1,098,415
Forfeited	(16,243)	(111,304)
Vested	(347,401)	—
At December 31, 2023	352,447	987,111

The following table provides a summary of the weighted average unit grant date fair value, weighted average remaining contractual term, total compensation cost and unrecognized compensation cost for the pre-IPO awards:


December 31, 2023	Restricted Stock - Pre-IPO B-1		Restricted Stock - Pre-IPO B-2		All Awards
(dollars in millions, except per award values)
Weighted average grant date fair value per unit of unvested units(a)	$	5.48	$	1.81	$	2.77
Weighted average remaining contractual term	1.31 years		N/A		N/A
Total compensation cost recognized during 2023	$	2.0	$	—	$	2.0
Unrecognized compensation expense at December 31, 2023	$	2.1	$	—	$	2.1

(a)Due to the in-kind distribution of shares of our common stock in connection with our IPO described above, the weighted average grant date fair value per unit is not comparable to the IPO share price.

N/A – not applicable

2020 Omnibus Incentive Plan

We maintain a long-term incentive plan (the “2020 Omnibus Incentive Plan” or the “2020 Plan”) that allows for grants of incentive stock options to employees (including employees of any of our subsidiaries), nonstatutory stock options, restricted stock awards (“RSAs”), restricted stock units (“RSUs”) and other cash-based, equity-based or equity-related awards to employees, directors, and consultants, including employees or consultants of our subsidiaries. The maximum number of shares of our common stock that may be issued under the 2020 Plan is 27.9 million. At December 31, 2023, 17.6 million shares are available for future issuance. The Company plans to issue shares available under the 2020 Plan or shares from treasury to satisfy requirements of awards paid with shares.

We recognize share-based compensation expense at grant date fair value over the requisite service period on a straight-line basis in our Consolidated Statements of Operations and Comprehensive Income (Loss), in “Selling, general and administrative expenses”. We recognized $30.4 million ($14.4 million for stock options and $16.0 million for RSAs and RSUs), $19.1 million ($7.8 million for stock options and $11.3 million for RSUs) and $11.3 million ($5.1 million for stock options and $6.2 million for RSUs) of share-based compensation expense for these awards for the years ending December 31, 2023, 2022 and 2021, respectively.

Stock Options

We use a Black-Scholes option pricing model to estimate the fair value of stock options. Since we are a newly public company, the expected volatility is based on the volatility of similar publicly traded businesses within the same or similar industry as the Company in combination with our own volatility. We used the simplified method to estimate the expected term. The risk-free rate is based on the U.S. Treasury yield in effect at the time of the grant.

Weighted-average grant-date fair values of stock options and the assumptions used in estimating the fair values are as follows:


For the year ended December 31,	2023			2022			2021
Weighted average grant date fair value per option	$	7.13		$	4.86		$	9.08
Expected term (years)	6 years			5.8 years			6.3 years
Risk-free interest rate	4.2		%	3.4		%	1.2		%
Expected volatility	50.0		%	45.7		%	37.5		%

Stock options generally vest ratably over a period of two to four years. They have an exercise price equal to the fair market value of a share of common stock on the date of grant, and a contractual term of 10 years. The following table summarizes our stock option activity for the year ended December 31, 2023:


	Number of Shares	Weighted-average Exercise Price		Remaining Contractual Life	Aggregate Intrinsic Value (millions of U.S. dollars)
Outstanding at the beginning of the year	5,990,470	$	14.84
Granted	1,100,329	17.52
Forfeited	(118,138)	20.43
Exercised	—	—
Outstanding at the end of the year	6,972,661	$	15.17	8.2 years	$	28.5
Exercisable at the end of the year	2,828,011	$	17.08	7.7 years
Unvested at the end of the year	4,144,650	$	13.87	8.6 years

At December 31, 2023 the total unrecognized compensation expense related to stock options expected to be recognized over the weighted-average period of approximately 1.5 years is $18.3 million. The total fair value of stock options vested during the years ended December 31, 2023, 2022 and 2021was $10.6 million, $4.4 million and $5.0 million, respectively.

RSUs

RSUs generally vest ratably over a period of one to four years and are valued based on the market price on the date of grant. The following table summarizes our unvested RSUs activity for the year ended December 31, 2023:


	Number of Shares	Weighted-average Grant Date Fair Value
Unvested at the beginning of the year	2,482,435	$	13.09
Granted	921,472	16.95
Forfeited	(180,754)	12.09
Vested	(924,317)	15.37
Unvested at the end of the year	2,298,836	$	13.81

As of December 31, 2023, total unrecognized compensation expense related to RSUs expected to be recognized over the weighted-average period of approximately 1.7 years is $22.4 million. The total fair value of RSUs vested during the years ended December 31, 2023, 2022 and 2021 was $14.1 million, $5.7 million and $5.1 million, respectively.

Consolidated Statements of Operations and Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Pension and post-retirement benefits, tax	$ (3,420)	$ 7,022	$ 8,924
Interest rate swaps, tax	$ (5,467)	$ 7,387	$ 142

Long-Term Debt - Aggregate Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
2024	$ 5,000
2025	5,000
2026	2,250,600
Thereafter	0
Total	$ 2,260,600	$ 1,963,550

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 296,407	$ 395,214
Restricted cash short-term	5,247	1,080
Accounts receivable, net of allowance for uncollectible accounts of $4,689 and $1,871 as of December 31, 2023 and 2022, respectively	147,696	118,482
Inventories, net	48,316	37,145
Prepaid expenses and other current assets	53,846	80,995
Income taxes receivable	5,732	12,094
Total current assets	557,244	645,010
Property, plant, and equipment, net	946,914	774,527
Operating lease assets	24,037	26,481
Deferred income taxes	4,993	4,101
Post-retirement assets	28,482	35,570
Other assets	41,242	38,983
Other intangible assets, net	416,318	491,265
Goodwill	1,111,190	1,101,768
Total assets	3,130,420	3,117,705
Current liabilities:
Accounts payable	71,039	74,139
Accrued liabilities	122,471	490,130
Deferred revenue	13,492	12,140
Current portion of long-term debt	4,797	197,119
Current portion of finance lease obligations	8,771	1,722
Current portion of operating lease obligations	5,934	7,554
Current portion of asset retirement obligations	0	2,896
Income taxes payable	4,150	5,867
Total current liabilities	230,654	791,567
Long-term debt	2,223,674	1,747,115
Finance lease obligations, less current portion	63,793	56,955
Operating lease obligations, less current portion	20,087	21,577
Noncurrent asset retirement obligations	47,944	42,586
Deferred lease income	18,762	18,902
Post-retirement obligations	8,439	7,910
Noncurrent liabilities	8,879	12,831
Deferred income taxes	64,454	68,024
Total liabilities	2,686,686	2,767,467
See Commitments and contingencies note
Equity:
Common stock, with $0.01 par value, 1,200,000 shares authorized; 286,037 shares issued at December 31, 2023 and 2022	2,860	2,860
Preferred stock, with $0.01 par value, 120,000 shares authorized; no shares issued at December 31, 2023 and 2022	0	0
Treasury stock, at cost (3,207 and 3,616 shares at December 31, 2023 and 2022, respectively)	(27,182)	(29,775)
Additional paid-in capital	1,215,178	1,189,622
Retained deficit	(654,440)	(705,816)
Accumulated other comprehensive loss	(92,682)	(106,653)
Total equity	443,734	350,238
Total liabilities and equity	$ 3,130,420	$ 3,117,705

Income Taxes

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

The geographic sources of income (loss) before income taxes were as follows:


(thousands of U.S. dollars)
Year ended December 31,	2023		2022		2021
U.S.	$	(100,635)	$	(418,308)	$	5,092
Foreign	206,662		175,197		170,624
Income (loss) before income taxes	$	106,027	$	(243,111)	$	175,716

Provision (benefit) for income taxes consisted of the following:


(thousands of U.S. dollars)
Year ended December 31,	2023		2022		2021
Current
Federal U.S.	$	(3,809)	$	12,841	$	13,915
State U.S.	924		5,082		3,220
Foreign	54,087		46,496		45,176
Total current provision	51,202		64,419		62,311
Deferred
Federal U.S.	6,933		(52,382)		(2,422)
State U.S.	(619)		(17,919)		391
Foreign	(2,865)		(3,659)		(1,685)
Total deferred provision (benefit)	3,449		(73,960)		(3,716)
Total provision (benefit) for income taxes	$	54,651	$	(9,541)	$	58,595

The provision (benefit) for income taxes is reconciled with the U.S. federal statutory rate as follows:


(thousands of U.S. dollars)
Year ended December 31,	2023		2022		2021
Provision (benefit) computed at federal statutory rate	$	22,265	$	(51,053)	$	36,872
Increase (decrease) in taxes as a result of:
State taxes, net of federal benefit	(2,889)		(20,359)		1,013
Valuation allowance	19,494		53,860		8,455
Global intangible low-tax income (“GILTI”)	4,861		1,427		2,103
Nondeductible share-based compensation	3,192		2,510		1,512
Foreign tax rate differential	10,595		8,335		8,005
Impact of rate changes on deferred tax balances	(92)		(1,184)		2,612
Tax holiday	(1,082)		(605)		(706)
Audit settlement	739		276		276
Tax credits	—		(172)		(248)
Other	(2,432)		(2,576)		(1,299)
Total provision (benefit) for income taxes	$	54,651	$	(9,541)	$	58,595

The components of the tax effects of temporary differences and carryforwards that gave rise to significant portions of the deferred tax assets and liabilities are as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Net operating loss carryforwards	$	71,552	$	9,286
Net capital loss carryforwards	4,686		4,666
Reserves and accruals	26,591		121,685
Employee benefits and compensation	8,519		6,610
Asset retirement obligations	11,140		10,649
Lease liability	8,733		9,506
Disallowed interest carryforward	129,320		89,682
Other	10,806		6,561
Deferred tax assets before valuation allowance	271,347		258,645
Valuation allowance	(125,435)		(105,600)
Net deferred tax assets	145,912		153,045

Depreciation and amortization	(195,450)		(199,670)

Other	(9,923)		(17,298)
Total deferred tax liabilities	(205,373)		(216,968)
Net deferred tax liabilities	$	(59,461)	$	(63,923)
Noncurrent net deferred tax assets	$	4,993	$	4,101
Noncurrent net deferred tax liabilities	(64,454)		(68,024)
Noncurrent net deferred tax liabilities	$	(59,461)	$	(63,923)

At December 31, 2023 and 2022, the Company had available U.S. federal net operating loss carryforwards of $235.0 million and $0, respectively, which have no expiration date. At December 31, 2023 and 2022, the Company had available state net operating loss carryforwards of $298.8 million and $28.3 million, respectively, of which $103.6 million have no expiration date, and foreign net operating loss carryforwards of approximately $23.4 million and $29.3 million, respectively, the majority of which have no expiration date. At December 31, 2023 and 2022, a valuation allowance was established against foreign net operating loss carryforwards for $4.4 million and $3.0 million, respectively. At December 31, 2023 and 2022 we also established a valuation allowance against U.S. federal net operating loss carryforwards of $6.8 million, and $0, respectively, and state net operating loss carryforwards for $11.3 million and $1.9 million, respectively. Based on management’s assessment, it is not more likely than not that these deferred tax assets will be realized through future taxable income.

At December 31, 2023 and 2022, no deferred tax liability has been recorded for repatriation of earnings for purposes of the Company’s consolidated financial statements as these earnings are deemed to be indefinitely reinvested. Determining the amount of unrecognized deferred tax liability related to any remaining undistributed foreign earnings not subject to the transition tax and additional outside basis difference in these entities (i.e., basis difference in excess of that subject to the one-time transition tax) is not practicable.

As of December 31, 2023 and 2022, the gross reserve for uncertain tax positions, excluding accrued interest and penalties, was $0, as noted in the following reconciliation.

The Company’s unrecognized income tax benefits were as follows:


(thousands of U.S. dollars)
For the period from January 1 – December 31,	2023		2022
Gross unrecognized tax benefits, beginning of year	$	—	$	116
Additions related to current year	—		—

Reductions related to prior years	—		(116)
Settlements	—		—

Gross unrecognized tax benefits, end of period	$	—	$	—

The Company recognizes interest and penalties as part of the provision for income taxes. For the years ended December 31, 2023, 2022 and 2021 interest and penalties related to uncertain income tax positions that were recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) were not material.

The Company, which represents all of its subsidiaries, files income tax returns in the U.S. federal jurisdiction and various states and foreign jurisdictions. The Company is no longer subject to U.S. federal, state, and local tax examinations before 2016, and non-U.S. income tax examinations by tax authorities for years before 2012. Tax years through December 31, 2018 have been audited by the Internal Revenue Service (“IRS”) and are effectively closed for U.S. federal income tax purposes and no other fiscal years are currently under audit. For Nordion’s Canadian tax, all tax years through October 31, 2018 have been closed through audit or statute, and no other fiscal years are currently under audit.

A portion of the Company’s foreign operations benefit from a tax holiday, which is set to expire in 2030. This tax holiday may be terminated early if certain conditions are not met. The tax benefit attributable to this holiday was $1.1 million and $0.6 million for the fiscal years ended December 31, 2023 and 2022, respectively.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Financial Instruments and Financial Risk - Assets and Liabilities Measured (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Derivative asset	$ 11,624,000	$ 37,485,000
Derivative liabilities	414,000	3,780,000
Derivatives Designated in Hedge Relationships \| Interest rate caps
Derivative [Line Items]
Derivative asset	8,763,000	34,764,000
Derivative liabilities	0	0
Derivatives Designated in Hedge Relationships \| Interest rate swaps
Derivative [Line Items]
Derivative asset	1,487,000	0
Derivative liabilities	0	0
Derivatives Designated in Hedge Relationships \| Fair Value, Level 1 \| Interest rate caps
Derivative [Line Items]
Derivative asset	0	0
Derivatives Designated in Hedge Relationships \| Fair Value, Level 1 \| Interest rate swaps
Derivative [Line Items]
Derivative asset	0
Derivatives Designated in Hedge Relationships \| Fair Value, Level 2 \| Interest rate caps
Derivative [Line Items]
Derivative asset	8,763,000	34,764,000
Derivatives Designated in Hedge Relationships \| Fair Value, Level 2 \| Interest rate swaps
Derivative [Line Items]
Derivative asset	1,487,000
Derivatives Designated in Hedge Relationships \| Fair Value, Level 3 \| Interest rate caps
Derivative [Line Items]
Derivative asset	0	0
Derivatives Designated in Hedge Relationships \| Fair Value, Level 3 \| Interest rate swaps
Derivative [Line Items]
Derivative asset	0
Derivatives Designated in Hedge Relationships \| Carrying Amount \| Interest rate caps
Derivative [Line Items]
Derivative asset	8,763,000	34,764,000
Derivatives Designated in Hedge Relationships \| Carrying Amount \| Interest rate swaps
Derivative [Line Items]
Derivative asset	1,487,000
Derivatives Not Designated in Hedge Relationships \| Embedded derivatives(a)
Derivative [Line Items]
Derivative asset	1,225,000	2,721,000
Derivative liabilities	405,000	3,508,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Term loan, due 2026
Derivative [Line Items]
Long-term debt	0	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Finance Lease Obligations (with current portion)
Derivative [Line Items]
Long-term debt	0	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Revolving Credit Facility
Derivative [Line Items]
Current portion of long-term debt		0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Term loan B, due 2026
Derivative [Line Items]
Current portion of long-term debt	0
Long-term debt	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Other long-term debt
Derivative [Line Items]
Current portion of long-term debt		0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Interest rate caps
Derivative [Line Items]
Derivative asset		0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Foreign currency forward
Derivative [Line Items]
Derivative asset	0	0
Derivative liabilities	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 1 \| Embedded derivatives(a)
Derivative [Line Items]
Derivative asset	0
Derivative liabilities	0	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Term loan, due 2026
Derivative [Line Items]
Long-term debt	1,758,163,000	1,626,460,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Finance Lease Obligations (with current portion)
Derivative [Line Items]
Long-term debt	72,564,000	58,677,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Revolving Credit Facility
Derivative [Line Items]
Current portion of long-term debt		196,672,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Term loan B, due 2026
Derivative [Line Items]
Current portion of long-term debt	5,000,000
Long-term debt	492,500,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Other long-term debt
Derivative [Line Items]
Current portion of long-term debt		447,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Interest rate caps
Derivative [Line Items]
Derivative asset		2,721,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Foreign currency forward
Derivative [Line Items]
Derivative asset	149,000	272,000
Derivative liabilities	9,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 2 \| Embedded derivatives(a)
Derivative [Line Items]
Derivative asset	1,225,000
Derivative liabilities	405,000	3,508,000
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Term loan, due 2026
Derivative [Line Items]
Long-term debt	0	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Finance Lease Obligations (with current portion)
Derivative [Line Items]
Long-term debt	0	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Revolving Credit Facility
Derivative [Line Items]
Current portion of long-term debt		0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Term loan B, due 2026
Derivative [Line Items]
Current portion of long-term debt	0
Long-term debt	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Other long-term debt
Derivative [Line Items]
Current portion of long-term debt		0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Interest rate caps
Derivative [Line Items]
Derivative asset		0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Foreign currency forward
Derivative [Line Items]
Derivative asset	0	0
Derivative liabilities	0
Derivatives Not Designated in Hedge Relationships \| Fair Value, Level 3 \| Embedded derivatives(a)
Derivative [Line Items]
Derivative asset	0
Derivative liabilities	0	0
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Term loan, due 2026
Derivative [Line Items]
Long-term debt	1,751,197,000	1,747,115,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Finance Lease Obligations (with current portion)
Derivative [Line Items]
Long-term debt	72,564,000	58,677,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Revolving Credit Facility
Derivative [Line Items]
Current portion of long-term debt		196,672,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Term loan B, due 2026
Derivative [Line Items]
Current portion of long-term debt	4,797,000
Long-term debt	472,477,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Other long-term debt
Derivative [Line Items]
Current portion of long-term debt		447,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Interest rate caps
Derivative [Line Items]
Derivative asset		2,721,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Foreign currency forward
Derivative [Line Items]
Derivative asset	149,000	272,000
Derivative liabilities	9,000
Derivatives Not Designated in Hedge Relationships \| Carrying Amount \| Embedded derivatives(a)
Derivative [Line Items]
Derivative asset	1,225,000
Derivative liabilities	$ 405,000	$ 3,508,000

Share-Based Compensation - Summary of Pre-IPO Awards (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per unit of unvested units (in dollars per share) \| $ / shares	$ 2.77
Total compensation cost recognized	$ 2,000
Unrecognized compensation expense at December 31, 2023	$ 2,100
Restricted Stock \| Pre-IPO B-1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per unit of unvested units (in dollars per share) \| $ / shares	$ 5.48
Weighted average remaining contractual term	1 year 3 months 21 days
Total compensation cost recognized	$ 2,000
Unrecognized compensation expense at December 31, 2023	$ 2,100
Restricted Stock \| Pre-IPO B-2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per unit of unvested units (in dollars per share) \| $ / shares	$ 1.81
Total compensation cost recognized	$ 0
Unrecognized compensation expense at December 31, 2023	$ 0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Commitments and Contingencies (Details)					1 Months Ended	12 Months Ended
Commitments and Contingencies (Details)	Feb. 23, 2023 USD ($)	Jan. 09, 2023 USD ($)	Sep. 19, 2022 USD ($)	Aug. 31, 2022 USD ($)	Oct. 31, 2023 USD ($) claim	Dec. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) case	Dec. 31, 2023 USD ($) plaintiff	Dec. 31, 2023 USD ($) claim	Dec. 31, 2022 case
Gain Contingencies [Line Items]
Loss contingency, insurance limits per occurrence						$ 10,000,000
Loss contingency, insurance limits						20,000,000
Personal Injury \| Cobb County
Gain Contingencies [Line Items]
Number of new claims filed \| claim									2
Number of cases to be stayed (in cases) \| claim									1
Pending Litigation
Gain Contingencies [Line Items]
Gross settlement				$ 110,200,000
Pending Litigation \| Gwinnett County
Gain Contingencies [Line Items]
Amount awarded to other party					$ 35,000,000
Pending Litigation \| Personal Injury \| Cobb County
Gain Contingencies [Line Items]
Number of plaintiffs \| plaintiff								245
Number of cases that will proceed to judicial determination (in cases) \| case							8
Number of cases including personal injury and property claims (in cases) \| case							9
Illinois EO litigation settlement
Gain Contingencies [Line Items]
Number of pending claims \| case										880
Illinois EO litigation settlement \| Pending Litigation
Gain Contingencies [Line Items]
Number of claims scheduled for trials \| case										2
Amount awarded to other party		$ 408,000,000	$ 358,700,000			408,000,000
Illinois EO litigation settlement \| Pending Litigation \| Punitive Damages
Gain Contingencies [Line Items]
Amount awarded to other party			$ 320,000,000
Asset Transfer Case \| Pending Litigation
Gain Contingencies [Line Items]
Amount awarded to other party	$ 408,000,000
Asset Transfer Case \| Pending Litigation \| Personal Injury \| Cook County
Gain Contingencies [Line Items]
Number of plaintiffs \| plaintiff								2
Number of new claims filed \| claim									23
Number of cases removed to United States District Court (in cases) \| case							3
Georgia EO litigation settlement \| Gwinnett County
Gain Contingencies [Line Items]
Number of pending claims \| claim					79,000,000
Georgia EO litigation settlement \| Property Devaluation \| Cobb County
Gain Contingencies [Line Items]
Number of new claims filed							10		365
Georgia EO litigation settlement \| Property Devaluation \| Cobb County \| Discovery In Process
Gain Contingencies [Line Items]
Number of new claims filed \| case							5
Georgia EO litigation settlement \| Property Devaluation \| Cobb County \| Dispositive Motions Remain Pending
Gain Contingencies [Line Items]
Number of new claims filed \| case							5
Atlanta Settlement \| Personal Injury
Gain Contingencies [Line Items]
Number of pending claims \| claim					78,000,000
Nordion
Gain Contingencies [Line Items]
Minimum purchase commitments						$ 1,607,100,000	$ 1,607,100,000	$ 1,607,100,000	$ 1,607,100,000
Nordion \| Minimum
Gain Contingencies [Line Items]
Term of contract						1 year	1 year	1 year	1 year
Nordion \| Maximum
Gain Contingencies [Line Items]
Term of contract						40 years	40 years	40 years	40 years

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

Property, plant, and equipment, net, consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Land and buildings	$	345,309	$	317,930
Leasehold improvements	82,582		67,386
Machinery, equipment, including Co-60	710,000		577,670
Furniture and fixtures	8,754		7,747
Computer hardware and software	51,437		44,796
Asset retirement costs	6,590		4,255
Construction-in-progress	247,019		193,639
	1,451,691		1,213,423
Less accumulated depreciation	(504,777)		(438,896)
Property, plant and equipment, net	$	946,914	$	774,527

Depreciation and amortization expense for property, plant, and equipment, including property under finance leases, was $76.6 million, $64.3 million and $64.2 million for the years ended December 31, 2023, 2022 and 2021, respectively. Capitalized interest totaled $12.2 million, $3.7 million and $1.1 million for the years ended December 31, 2023, 2022 and 2021, respectively, and was recorded as a reduction in “Interest expense, net” in the Consolidated Statements of Operations and Comprehensive Income (Loss).

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2023
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Cleveland, Ohio
Auditor Firm ID	42

Income Taxes - Schedule of Total Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current
Federal U.S.	$ (3,809)	$ 12,841	$ 13,915
State U.S.	924	5,082	3,220
Foreign	54,087	46,496	45,176
Total current provision	51,202	64,419	62,311
Deferred
Federal U.S.	6,933	(52,382)	(2,422)
State U.S.	(619)	(17,919)	391
Foreign	(2,865)	(3,659)	(1,685)
Total deferred provision (benefit)	3,449	(73,960)	(3,716)
Total provision (benefit) for income taxes	$ 54,651	$ (9,541)	$ 58,595

Financial Instruments and Financial Risk (Tables)

12 Months Ended

Dec. 31, 2023

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative Instruments

The following table provides a summary of the notional and fair values of our derivative instruments:


	December 31, 2023						December 31, 2022
(in U.S. dollars; notional in millions, fair value in thousands)			Fair Value						Fair Value
	Notional Amount		Derivative Assets		Derivative Liabilities		Notional Amount		Derivative Assets		Derivative Liabilities
Derivatives designated as hedging instruments
Interest rate caps	$	1,000.0	$	8,763	$	—	$	2,000.0	$	34,764	$	—
Interest rate swaps	400.0		1,487		—		—		—		—
Derivatives not designated as hedging instruments
Foreign currency forward contracts	171.0		149		9		151.5		—		272
Embedded derivatives(a)	150.1		1,225		405		179.9		2,721		3,508
Total	$	1,721.1	$	11,624	$	414	$	2,331.4	$	37,485	$	3,780

(a)Represents the total notional amounts for certain of the Company’s supply and sales contracts accounted for as embedded derivatives.

Schedule of Derivative Instruments, Gain (Loss)


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
Unrealized loss (gain) on interest rate derivatives recorded in interest expense, net	$	—	$	—	$	(1,185)
Realized (gain) loss on interest rate derivatives recorded in interest expense, net(a)	(33,094)		(12,226)		—
Unrealized (gain) loss on embedded derivatives recorded in other (income)/ expense, net	(1,637)		1,324		(1,195)
Realized (gain) loss on foreign currency forward contracts recorded in foreign exchange (gain) loss	(2,025)		3,931		(1,900)
Unrealized (gain) loss on foreign currency forward contracts recorded in foreign exchange (gain) loss	(412)		272		—

(a) For the years ended December 31, 2023 and December 31, 2022, amounts represent periodic settlement of interest rate caps and swaps.

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following table discloses the fair value our financial assets and liabilities:


As of December 31, 2023			Fair Value
(thousands of U.S. dollars)	Carrying Amount		Level 1		Level 2		Level 3
Derivatives designated as hedging instruments(a)
Interest rate caps	$	8,763	$	—	$	8,763	$	—
Interest rate swaps	1,487		—		1,487		—
Derivatives not designated as hedging instruments(b)
Foreign currency forward contract assets	149		—		149		—
Foreign currency forward contract liabilities	9		—		9		—
Embedded derivative assets	1,225		—		1,225		—
Embedded derivative liabilities	405		—		405		—
Current portion of long-term debt(c)
Term loan B, due 2026	4,797		—		5,000		—
Long-Term Debt(c)
Term loan, due 2026	1,751,197		—		1,758,163		—
Term loan B, due 2026	472,477		—		492,500		—
Finance Lease Obligations (with current portion)(d)	72,564		—		72,564		—


As of December 31, 2022			Fair Value
(thousands of U.S. dollars)	Carrying Amount		Level 1		Level 2		Level 3
Derivatives designated as hedging instruments(a)
Interest rate caps	$	34,764	—		34,764		—
Derivatives not designated as hedging instruments(b)
Foreign currency forward contracts	272		—		272		—
Interest rate caps	2,721		$	—	$	2,721	$	—
Embedded derivative liabilities	3,508		—		3,508		—
Current portion of long-term debt(e)
Revolving credit facility	196,672		—		196,672		—
Other long-term debt	447		—		447		—
Long-Term Debt(c)
Term loan, due 2026	1,747,115		—		1,626,460		—
Finance Lease Obligations (with current portion)(d)	58,677		—		58,677		—

(d)Refer to Note 18, “Leases”. Fair value approximates carrying value.

Schedule of Fair Value, Assets and Liabilities Measured on Nonrecurring Basis

The following table discloses the fair value our financial assets and liabilities:


As of December 31, 2023			Fair Value
(thousands of U.S. dollars)	Carrying Amount		Level 1		Level 2		Level 3
Derivatives designated as hedging instruments(a)
Interest rate caps	$	8,763	$	—	$	8,763	$	—
Interest rate swaps	1,487		—		1,487		—
Derivatives not designated as hedging instruments(b)
Foreign currency forward contract assets	149		—		149		—
Foreign currency forward contract liabilities	9		—		9		—
Embedded derivative assets	1,225		—		1,225		—
Embedded derivative liabilities	405		—		405		—
Current portion of long-term debt(c)
Term loan B, due 2026	4,797		—		5,000		—
Long-Term Debt(c)
Term loan, due 2026	1,751,197		—		1,758,163		—
Term loan B, due 2026	472,477		—		492,500		—
Finance Lease Obligations (with current portion)(d)	72,564		—		72,564		—


As of December 31, 2022			Fair Value
(thousands of U.S. dollars)	Carrying Amount		Level 1		Level 2		Level 3
Derivatives designated as hedging instruments(a)
Interest rate caps	$	34,764	—		34,764		—
Derivatives not designated as hedging instruments(b)
Foreign currency forward contracts	272		—		272		—
Interest rate caps	2,721		$	—	$	2,721	$	—
Embedded derivative liabilities	3,508		—		3,508		—
Current portion of long-term debt(e)
Revolving credit facility	196,672		—		196,672		—
Other long-term debt	447		—		447		—
Long-Term Debt(c)
Term loan, due 2026	1,747,115		—		1,626,460		—
Finance Lease Obligations (with current portion)(d)	58,677		—		58,677		—

(d)Refer to Note 18, “Leases”. Fair value approximates carrying value.

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References + Details

Revenue Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
Revenue Recognition (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total net revenues	$ 1,049,288	$ 1,003,687	$ 931,478
Deferred revenue	13,492	12,140
Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	820,877	774,145	710,964
Over time
Disaggregation of Revenue [Line Items]
Total net revenues	228,411	229,542	220,514
Sterigenics
Disaggregation of Revenue [Line Items]
Total net revenues	667,130	626,646	571,829
Sterigenics \| Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	667,130	626,646	571,829
Sterigenics \| Over time
Disaggregation of Revenue [Line Items]
Total net revenues	0	0	0
Nordion
Disaggregation of Revenue [Line Items]
Total net revenues	160,459	153,639	140,507
Nordion \| Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	153,747	147,499	139,135
Nordion \| Over time
Disaggregation of Revenue [Line Items]
Total net revenues	6,712	6,140	1,372
Nelson Labs
Disaggregation of Revenue [Line Items]
Total net revenues	221,699	223,402	219,142
Nelson Labs \| Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	0	0	0
Nelson Labs \| Over time
Disaggregation of Revenue [Line Items]
Total net revenues	$ 221,699	$ 223,402	$ 219,142

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

- Definition

+ References

+ Details

Segment and Geographic Information - Reconciliation of Reportable Segment Amounts (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Share-based compensation			$ 32,238	$ 21,211	$ 13,870
Impairment of investment in unconsolidated affiliate			0	9,613	0
Loss on extinguishment of debt			0	0	20,681
Accretion expense			2,413	2,194	2,252
Net income (loss) attributable to Sotera Health Company			51,376	(233,570)	116,882
Unrealized loss (gain)			1,637	(2,977)	1,195
Gain on Business Interruption Insurance Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration]		Other Nonoperating Income (Expense)
Derivatives Not Designated in Hedge Relationships
Segment Reporting Information [Line Items]
Unrealized loss (gain)				1,700
Illinois EO litigation settlement
Segment Reporting Information [Line Items]
Litigation settlement			0	408,000	0
Georgia EO litigation settlement
Segment Reporting Information [Line Items]
Litigation settlement			35,000	0	0
Nordion
Segment Reporting Information [Line Items]
Gain on insurance settlement		$ 3,400
ARO, non-cash gain from derecognition	$ 5,100
Cancellation fee received			1,000
Interest Expense, Net \| Term loan B, due 2026
Segment Reporting Information [Line Items]
Interest expense, net			26,800
Interest rate caps
Segment Reporting Information [Line Items]
Unrealized loss (gain)			0	0	1,185
Operating Segments
Segment Reporting Information [Line Items]
Segment income			528,029	506,249	481,229
Operating Segments \| Nordion
Segment Reporting Information [Line Items]
Segment income			96,678	89,477	82,673
Segment Reconciling Items
Segment Reporting Information [Line Items]
Interest expense, net			116,068	78,490	74,192
Depreciation and amortization			157,925	145,554	150,902
Share-based compensation			32,364	21,211	13,870
Loss (gain) on foreign currency and derivatives not designated as hedging instruments, net			(1,552)	3,150	(58)
Acquisition and divestiture related charges, net			937	1,398	(6,018)
Business optimization project expenses			7,310	2,226	948
Plant closure expenses			(585)	4,730	2,327
Impairment of investment in unconsolidated affiliate			0	9,613	0
Loss on extinguishment of debt			0	0	20,681
Professional services relating to EO sterilization facilities			72,122	72,639	45,656
Accretion expense			2,413	2,194	2,252
COVID-19 expenses			0	155	761
Net income (loss) attributable to Sotera Health Company			106,027	(243,111)	175,716
Segment Reconciling Items \| Illinois EO litigation settlement
Segment Reporting Information [Line Items]
Litigation settlement			0	408,000	0
Segment Reconciling Items \| Georgia EO litigation settlement
Segment Reporting Information [Line Items]
Litigation settlement			$ 35,000	$ 0	$ 0

Employee Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 525	$ 969	$ 1,204
Service cost	681	1,118
Interest cost	10,917	7,411	6,516
Expected return on plan assets	(16,108)	(14,421)	(14,370)
Amortization of net actuarial gain	0	0	1,079
Net periodic benefit cost	(4,666)	(6,041)	(5,571)
Other post-retirement benefits plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	16	28
Interest cost	398	284	268
Amortization of net actuarial gain	(197)	(171)	(34)
Net periodic benefit cost	$ 210	$ 129	$ 262

Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of Equity Instruments, Valuation Assumptions

The assumptions used to calculate the fair value of the pre-IPO awards were as follows:


	2020
Risk-free interest rate	1.6	%
Expected volatility	50	%
Expected dividends	None
Expected time until exercise (years)	0.6

Schedule of Pre-IPO Restricted Stock Units Activity


	Restricted Stock - Pre-IPO B-1	Restricted Stock - Pre-IPO B-2
At January 1, 2021	2,201,239	2,323,333
Forfeited	(72,467)	(299,374)
Vested	(922,683)	—
At December 31, 2021	1,206,089	2,023,959
Forfeited	(54,333)	(925,544)
Vested	(435,665)	—
At December 31, 2022	716,091	1,098,415
Forfeited	(16,243)	(111,304)
Vested	(347,401)	—
At December 31, 2023	352,447	987,111

Schedule of Share-based Payment Arrangement, Pre-IPO Awards


December 31, 2023	Restricted Stock - Pre-IPO B-1		Restricted Stock - Pre-IPO B-2		All Awards
(dollars in millions, except per award values)
Weighted average grant date fair value per unit of unvested units(a)	$	5.48	$	1.81	$	2.77
Weighted average remaining contractual term	1.31 years		N/A		N/A
Total compensation cost recognized during 2023	$	2.0	$	—	$	2.0
Unrecognized compensation expense at December 31, 2023	$	2.1	$	—	$	2.1

N/A – not applicable

Schedule of Stock Options, Valuation Assumptions

Weighted-average grant-date fair values of stock options and the assumptions used in estimating the fair values are as follows:


For the year ended December 31,	2023			2022			2021
Weighted average grant date fair value per option	$	7.13		$	4.86		$	9.08
Expected term (years)	6 years			5.8 years			6.3 years
Risk-free interest rate	4.2		%	3.4		%	1.2		%
Expected volatility	50.0		%	45.7		%	37.5		%

Schedule of Stock Option Activity


	Number of Shares	Weighted-average Exercise Price		Remaining Contractual Life	Aggregate Intrinsic Value (millions of U.S. dollars)
Outstanding at the beginning of the year	5,990,470	$	14.84
Granted	1,100,329	17.52
Forfeited	(118,138)	20.43
Exercised	—	—
Outstanding at the end of the year	6,972,661	$	15.17	8.2 years	$	28.5
Exercisable at the end of the year	2,828,011	$	17.08	7.7 years
Unvested at the end of the year	4,144,650	$	13.87	8.6 years

Schedule of Restricted Stock Activity


	Number of Shares	Weighted-average Grant Date Fair Value
Unvested at the beginning of the year	2,482,435	$	13.09
Granted	921,472	16.95
Forfeited	(180,754)	12.09
Vested	(924,317)	15.37
Unvested at the end of the year	2,298,836	$	13.81

Acquisitions	12 Months Ended
Acquisitions	Dec. 31, 2023
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Acquisitions Acquisition of Regulatory Compliance Associates Inc. On November 4, 2021, we acquired Regulatory Compliance Associates Inc. (“RCA”) for approximately $30.6 million, net of $0.6 million of cash acquired. RCA is an industry leader in providing life sciences consulting focused on quality, regulatory, and technical advisory services for the pharmaceutical, medical device and combination device industries. Headquartered in Pleasant Prairie, Wisconsin, RCA expands and further strengthens our technical consulting and expert advisory capabilities within our Nelson Labs segment. The purchase price of RCA was allocated to the underlying assets acquired and liabilities assumed based upon management's estimated fair values at the date of acquisition. Approximately $25.3 million of goodwill was recorded related to the RCA acquisition, representing the excess of the purchase price over the estimated fair values of all the assets acquired and liabilities assumed. We also recorded $6.4 million of finite-lived intangible assets, primarily related to customer relationships. We funded this acquisition using available cash. The acquisition price and the results of operations for this acquired entity are not material in relation to our consolidated financial statements.

Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Significant Accounting Policies

Principles of Consolidation – Sotera Health Company (also referred to herein as the “Company,” “we,” “our,” “us” or “its”), is a leading global provider of mission-critical end-to-end sterilization solutions, lab testing and advisory services for the healthcare industry with operations primarily in the Americas, Europe and Asia.

The accompanying consolidated financial statements include the assets, liabilities, operating results, and cash flows of the Company and its wholly owned subsidiaries prepared in accordance with U.S. generally accepted accounting principles (“GAAP”).

We operate and report in three segments, Sterigenics, Nordion and Nelson Labs. We describe our reportable segments in Note 22, “Segment and Geographic Information”. All intercompany balances and transactions have been eliminated in consolidation.

Noncontrolling interests represented the noncontrolling stockholders’ proportionate share of the total equity in the Company’s consolidated subsidiaries. In the second quarter of 2021, we purchased the outstanding noncontrolling interests of 15% and 33% of our two China subsidiaries. Prior to our acquisition of the noncontrolling interests in our two subsidiaries in China, we consolidated the results of operations of these subsidiaries with our results of operations and reflected the noncontrolling interest on our Consolidated Statements of Operations and Comprehensive Income (Loss) as “Net income attributable to noncontrolling interests.”

In July 2020, we acquired a 60% equity ownership interest in a joint venture to construct an E-beam facility in Alberta, Canada in connection with our acquisition of Iotron Industries Canada, Inc. (“Iotron”). Our equity ownership in the joint venture was determined to be an investment in a variable interest entity (“VIE”). The investment was not consolidated as the Company concluded that it was not the primary beneficiary of the VIE. The Company accounted for the joint venture using the equity method. The investment was reflected within “Investment in unconsolidated affiliates” on the Consolidated Balance Sheets. During the year ended December 31, 2022, we identified certain events and circumstances that indicated a decline in value of our investment in this joint venture that was other-than-temporary. Consequently, in the second quarter of 2022, we wrote down the investment in the joint venture to its fair value of $0, resulting in an impairment charge of approximately $9.6 million. In February 2023, we entered into a Share Purchase Agreement to transfer our equity ownership interest to the joint venture partner, thereby terminating our equity ownership interest.

Use of Estimates – In preparing our consolidated financial statements in conformity with U.S. Generally Accepted Accounting Principles (“GAAP”), we make estimates and assumptions that affect the amounts reported and the accompanying notes. We regularly evaluate the estimates and assumptions used and revise them as new information becomes available. Actual results may vary from those estimates.

Cash and Cash Equivalents – We consider all highly liquid investments purchased with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents may include various deposit accounts and money market funds.

Accounts Receivable - Accounts receivable consists of amounts billed and currently due from customers. The amounts due are stated net of the allowance for uncollectible accounts. The Company maintains an allowance for uncollectible receivables to provide for the estimated amount of receivables that will not be collected.

Allowance for Uncollectible Accounts Receivable – We maintain an allowance for uncollectible accounts receivable for estimated losses in the collection of amounts owed to us by customers. We estimate the allowance based on analyzing a number of factors, including amounts written off historically, customer payment practices, customer financial information and credit ratings, current market conditions as well as the expected future economic conditions that may impact the collection of accounts receivable. We also analyze significant customer accounts on a regular basis and record a specific allowance when we become aware of a specific customer’s inability to pay. We generally do not charge interest on accounts receivable or require collateral from our customers.

We record write-offs against the allowance for uncollectible accounts receivable when all reasonable efforts for collection have been exhausted. As a result, the related accounts receivable are reduced to an amount that we reasonably believe is collectible.

These analyses require judgment. If the financial condition of our customers worsens, or economic conditions change, we may be required to make changes to our allowance for uncollectible accounts receivable.

Inventories – Inventories as of December 31, 2023 and 2022 are held at Nordion. Inventories are stated at the lower of cost or net realizable value. Cost of material, labor, and manufacturing overhead are determined using standard cost, which approximates average cost. We review inventory on an ongoing basis, considering factors such as deterioration and obsolescence. We record a reserve for excess and obsolete inventory, which was immaterial at December 31, 2023 and 2022, when the facts and circumstances indicate that particular inventories will not be usable. If future market conditions vary from those projected, and our estimates prove to be inaccurate, we may be required to write-down inventory values and record an adjustment to cost of revenues.

Property, Plant, and Equipment – Property, plant, and equipment is carried at cost, or initially at fair value if acquired in an acquisition, less accumulated depreciation and amortization. Except for Co-60, a radioactive isotope used in gamma radiation sterilization, all property, plant, and equipment depreciation is computed using the straight-line method over estimated useful lives. Leasehold improvements are amortized over their estimated useful lives or the term of the related lease, whichever is shorter. Co-60 is amortized using an accelerated method, which relates to the natural radioactive decay of the isotope over its estimated useful life which is approximately twenty years. Amortization of Co-60 is included within depreciation expense as a cost of revenue. Expenditures for major software purchases and software developed for internal use are capitalized and depreciated using the straight-line method over the estimated useful lives of the related assets, which are generally one to five years. For software obtained or developed for internal use, all external direct costs for materials and services and certain personnel costs incurred to develop the software during the application development stage are capitalized. At December 31, 2023 and 2022, we had undepreciated software costs of $7.9 million and $3.4 million, respectively, included in property, plant, and equipment, net. We recognized $3.3 million, $2.2 million and $2.6 million, of depreciation expense related to software costs for the years ending December 31, 2023, 2022 and 2021, respectively.

Depreciation is computed using the assets’ estimated useful lives as presented below:


Buildings and building improvements			15–44 years
Machinery and equipment			3–30 years
Leasehold improvements			2–20 years
Furniture and fixtures			3–10 years
Computer hardware and software			1–7 years

From time to time, we build or expand facilities. The cost of construction of these facilities is reflected as construction-in-progress until the asset is ready for its intended use, at which time the costs are reclassified to the appropriate depreciable category of property, plant, and equipment and depreciation commences. Fixed asset projects requiring one or more years to complete construction qualify for capitalization of interest costs in accordance with our policy. Interest related to property, plant and equipment projects with a construction period of less than one year are not capitalized and are immaterial. Repairs and maintenance costs that do not extend the useful life of an asset are expensed as incurred.

Upon sale or retirement of assets, the cost and related accumulated depreciation is removed from the Consolidated Balance Sheets, and the resulting gain or loss is reflected as a component of operating income.

Long-Lived Assets Other than Goodwill – We review long-lived assets, including finite-lived intangibles for impairment whenever events or circumstances indicate that the carrying amount of the asset or asset group may be impaired. Events or circumstances which would result in an impairment assessment include operating losses, a significant change in the use of an asset or asset group, or the planned disposal or sale of the asset or asset group. The asset or asset group would be considered impaired when the future net undiscounted cash flows generated by the asset or asset group are less than its carrying value. An impairment loss would be recognized based on the amount by which the carrying value of the asset or asset group exceeds its estimated fair value.

Amortization of intangible assets is computed using the asset’s estimated useful lives as presented below:


Land-use rights			41 years
Customer contracts and related relationships			5–20 years
Proprietary technology			7–20 years
Trade name/trademark			5–8 years
Sealed source and supply agreements			7–20 years

Leases – We determine if an agreement contains a lease and classify our leases as operating or finance at the lease commencement date. Leases with an initial term of twelve months or less are recognized as lease expense on a straight-line basis over the lease term and are not recorded on the Consolidated Balance Sheets. Non-lease components are accounted for separately from the lease components for all asset classes.

Finance leases are those in which we will pay substantially all the underlying asset’s fair value or will use the asset for all or a major part of its economic life, including circumstances in which we will ultimately own the asset. Lease assets arising from finance leases are included in “Property, plant and equipment, net” and the liabilities are included in “Finance lease obligations” on the Consolidated Balance Sheets. For finance leases, we recognize interest expense using the effective interest method and we recognize amortization expense on the lease asset over the shorter of the lease term or the useful life of asset. Finance leases are accounted for as if the assets were owned and financed, with associated expense recognized in “Interest expense, net” and “Cost of revenues” or “Selling, general and administrative expenses” within the Consolidated Statements of Operations and Comprehensive Income (Loss) depending on the nature of the underlying asset.

Operating lease assets and liabilities are recognized at the commencement date of the lease based on the present value of lease payments over the lease term. Lease assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. As most leases do not provide an implicit interest rate, we estimate an incremental borrowing rate to determine the present value of lease payments. Our estimated incremental borrowing rate reflects a secured rate based on recent debt issuances, our estimated credit rating, and lease term. We recognize operating lease costs on a straight-line basis over the term of the lease in “Cost of revenues” or “Selling, general and administrative expenses” on the Consolidated Statements of Operations and Comprehensive Income (Loss) depending on the nature of the underlying asset.

Goodwill and Other Indefinite-Lived Intangibles – Goodwill and other indefinite-lived intangible assets, primarily certain regulatory licenses and tradenames, are tested for impairment annually as of October 1. If circumstances change during interim periods between annual tests that would indicate that the carrying amount of such assets may not be recoverable, the Company tests such assets at an interim date for impairment. Factors that necessitate an interim impairment assessment include prolonged negative industry or economic trends and significant underperformance relative to historical or projected future operating results.

We performed a quantitative assessment of all reporting units (Sterigenics, Nordion and Nelson Labs) as of October 1, 2023. The fair value of each reporting unit was calculated using a discounted cash flow analysis which was dependent on subjective market participant assumptions determined by management. We further corroborated these discounted cash flow analyses utilizing a market approach to determine the estimated enterprise fair value. Assumptions used in the analyses included discount rates, revenue growth rates and projected operating cash flows. Estimates of future cash flows are based upon relevant data at a point-in-time, are subject to change, and could vary from actual results. The estimated fair value of each reporting unit exceeded its carrying amount by a sufficient margin to support a positive assertion that goodwill is not impaired. We performed a qualitative impairment assessment to evaluate any potential impairment to the indefinite-lived intangible assets. We considered significant events and circumstances that could affect the significant inputs used to determine the estimated fair value of the indefinite-lived intangible assets, and determined, after considering the totality of evidence that it is not more likely than not that the indefinite-lived intangible assets are impaired. There have been no other significant events or circumstances that occurred since the annual assessment date of October 1 that would change the conclusions reached above.

Derivative Instruments – We may enter into derivative instruments and hedging activities to manage, where possible and economically efficient, commodity price risk, foreign currency exchange rate risk and interest rate risk related to borrowings.

We also have identified embedded derivatives in certain supply and customer contracts. Certain interest rate derivatives are designated as cash flow hedges allowing for changes in fair value to be recorded through “Other comprehensive income (loss)”. Amounts in accumulated other comprehensive income (loss) will be reclassified into earnings in the same periods during which the hedged transaction affects earnings and are presented in “Interest expense, net” within the Consolidated Statements of Operations and Comprehensive Income (Loss). Derivatives not designated as hedges are recorded at fair value on the Consolidated Balance Sheets, with any changes in the value being recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss) in the same line item as the corresponding hedged item. We classify cash flows from derivative instruments and hedging activities as cash flows from operating activities in the Consolidated Statements of Cash Flows. To the extent derivative arrangements are with the same counterparty and contractual right of offset exists under applicable master agreements, we offset assets and liabilities for reporting on the Consolidated Balance Sheets.

Pension, Post-Retirement and Other Post-Employment Benefit Plans – We sponsor a defined-contribution retirement plan that covers substantially all U.S. employees. We also sponsor various post-employment benefit plans at our Nordion business in Canada, including defined benefit and defined contribution pension plans, retirement compensation arrangements and plans that provide extended health care coverage to retired employees. In addition, we provide other benefit plans at our foreign subsidiaries, including a supplemental retirement arrangement, a retirement and termination allowance and post-retirement benefit plans, which include contributory healthcare benefits and contributory life insurance coverage. All non-pension post-employment benefit plans are unfunded.

These costs and obligations are affected by assumptions including the discount rate, the expected long-term rate of return on plan assets, the annual rate of change in compensation for eligible employees, estimated changes in costs of healthcare benefits, and other demographic and economic factors. We review the assumptions used on an annual basis.

We recognize the over/under funded status of defined benefit pension and post-retirement benefits plans in our Consolidated Balance Sheets. This amount is measured as the difference between the fair value of plan assets and the projected benefit obligation. Changes in the funded status of the plans are recorded in other comprehensive income (loss) in the year they occur. We measure plan assets and obligations as of the balance sheet date. We provide additional information about our pension and other post-retirement benefits plans in Note 12, “Employee Benefits”.

Amortization of net gain or loss included in accumulated other comprehensive income (loss) shall be reclassified to net periodic pension cost if, as of the beginning of the year, that gain or loss exceeds 10% of the greater of the projected benefit obligation (“PBO”) or the market related value of the plan assets (the ‘corridor’). As most of the plan’s participants are no longer actively accruing benefits, the average remaining life expectancy is used.

Asset Retirement Obligations (“ARO”) – ARO are legal obligations associated with the retirement of long-lived assets or the exit of a leased facility. We recognize a liability for an ARO in the period in which it is incurred if a reasonable estimate of fair value can be made, and the associated asset retirement costs are then capitalized as part of the carrying amount of the long-lived asset. We lease various facilities where sterilization and ionization services are performed. Under the lease agreements, we are required to return the facilities to their original condition and to perform decommissioning activities. In addition, certain of our owned facilities are required to be decommissioned when we vacate the facility. Accretion expense is recognized in cost of revenues in the Consolidated Statements of Operations and Comprehensive Income (Loss) over time as the discounted liability is accreted to its expected settlement value.

Debt Issuance Costs, Premiums and Discounts – We have incurred costs in connection with obtaining financing as well as premiums and discounts associated with our long-term debt. The portion of these fees that are capitalized are recorded as a reduction of debt on the Consolidated Balance Sheets and amortized into interest expense over the term of the debt agreement. Debt issuance costs associated with the Company’s revolving credit facilities are classified as assets unless there are outstanding borrowings under such arrangements.

Concentration of Credit Risk, Other Risks and Uncertainties – We maintain cash and cash equivalents in the form of demand deposits in accounts with major financial institutions in the U.S. and in countries where our subsidiaries operate. Deposits in these institutions may exceed amounts of insurance provided on such accounts. We have not experienced any losses on our deposits of cash and cash equivalents.

Our net revenues and accounts receivable are derived from customers located primarily in North America and Europe.

No customer accounted for 10% or more of accounts receivable at December 31, 2023 and 2022, or 10% or more of net revenues for the years ended December 31, 2023, 2022 and 2021.

Income Taxes –We use the liability method of accounting for income taxes whereby we recognize deferred tax assets and liabilities for the future tax consequences of temporary differences between the tax bases of assets and liabilities and their reported amounts in the consolidated financial statements. Deferred tax assets will be reduced by a valuation allowance if, based on management’s estimate, it is more likely than not that a portion of the deferred tax assets will not be realized in a future period. The estimates used in the recognition of deferred tax assets are subject to revision in future periods based on new facts and circumstances.

We determine whether it is more likely than not that a tax position will be sustained upon examination, including resolution of related appeals or litigation processes, based on the technical merits of the position. In evaluating whether a tax position has met the more-likely-than-not recognition threshold, we presume that the position will be examined by the appropriate taxing authority and that the taxing authority will have full knowledge of all relevant information. A tax position that meets the more-likely-than-not recognition threshold is measured at the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. Determining what constitutes an individual tax position and whether the more-likely-than-not recognition threshold is met for a tax position are matters of judgment based on the individual facts and circumstances of that position evaluated in light of all available evidence. We review and adjust tax estimates periodically because of ongoing examinations by, and settlements with, the various taxing authorities, as well as changes in tax laws, regulations, and precedent. We are subject to a tax on Global Intangible Low Taxed Income (“GILTI”) which we record as a period cost.

Our policy is to recognize interest and penalties related to income tax matters as a component of the provision for income taxes in our Consolidated Statements of Operations and Comprehensive Income (Loss).

Foreign Currency Translation – The functional currency of our foreign subsidiaries is generally the local currency. Accordingly, assets and liabilities are generally translated into U.S. dollars at the current rates of exchange as of the balance sheet date, and revenues and expenses are translated using weighted-average rates prevailing during the period. Adjustments from foreign currency translation are included as a separate component of accumulated other comprehensive income (loss).

Gains or losses arising from foreign currency transactions are recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) as foreign exchange loss (gain). The Company routinely enters into foreign currency forward contracts to manage foreign currency exchange rate risk of our intercompany loans in certain of our international subsidiaries and non-functional currency assets and liabilities. The foreign currency forward contracts expire on a monthly basis. For the years ended December 31, 2023, 2022 and 2021, foreign exchange loss related primarily to short-term losses (offset by short-term gains) on sales denominated in currencies other than the functional currency of our operating entities.

Revenue Recognition – Revenue is recognized when control of promised goods or services is transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. The majority of our sales agreements contain performance obligations satisfied at a point-in-time when control of promised goods or services have transferred to our customers. Sales recognized over time are generally accounted for using an input measure to determine progress completed as of the end of the period.

Refunds, returns, warranties and other related obligations are not material to any of our segments and we do not incur material incremental costs to secure customer contracts.

Our Sterigenics segment provides outsourced terminal sterilization and irradiation services for the medical device, pharmaceutical, food safety and advanced applications markets. We typically have multiyear service contracts with our significant customers, and these sales contracts are primarily based on customers’ purchase orders. Given the relatively short turnaround times, performance obligations are generally satisfied at a point-in-time upon the completion of sterilization or irradiation processing and approval by our quality assurance process. Sterigenics segment revenues are included in service revenues in our Consolidated Statements of Operations and Comprehensive Income (Loss).

Our Nordion segment is a global provider of Co-60 and gamma irradiation systems, which are key components to the gamma sterilization process. Revenue from the sale of Co-60 sources is recognized as product revenue at a point-in-time upon satisfaction of our performance obligations for delivery of existing sources. Revenue from the sale of gamma irradiation systems is recognized as product revenue over time using an input measure of costs incurred and is immaterial to the overall business. Revenues from Co-60 installation and disposal and gamma irradiation systems refurbishments and installations are recognized as service revenue.

Our Nelson Labs segment provides outsourced microbiological and analytical chemistry testing and advisory services for the medical device and pharmaceutical industries. We provide our customers mission-critical lab testing services, which assess the product quality, effectiveness, patient safety and end-to-end sterility of products. These services are necessary for our customers’ regulatory approvals, product releases and ongoing product performance evaluations. Nelson Labs services are generally provided on a fee-for-service or project basis, and we recognize revenues over time using an input measure of time incurred to determine progress completed at the end of the period. Nelson Labs segment revenues are included in service revenues in our Consolidated Statements of Operations and Comprehensive Income (Loss).

We do not capitalize sales commissions because substantially all of our sales commission programs have an amortization period of one year or less. Furthermore, costs to fulfill a contract are not material.

Provisions for discounts, rebates to customers, and other adjustments are provided for as reductions in net revenues in the period the related sale is recorded. Shipping and handling charges billed to customers are included in net revenues, and the related shipping and handling costs are included in cost of net revenues on the Consolidated Statements of Operations and Comprehensive Income (Loss). Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by us from a customer, are excluded from net revenue.

Payment terms vary by the type and location of the customer and the products or services offered. Generally, the time between when revenue is recognized and when payment is due is not significant. We do not evaluate whether the selling price contains a financing component for contracts that have a duration of less than one year.

Share-Based Compensation – Equity-based awards issued to employees under the Sotera Health Company 2020 Omnibus Incentive Plan (“2020 Plan”) include restricted stock units (“RSUs”) and stock options that vest over time. Prior to our initial public offering (the “IPO” as described in Note 15, “Stockholders' Equity”), equity-based awards were issued to employees and non-employee directors in the form of partnership interests in our predecessor, Sotera Health Topco Parent, L.P. (“Topco Parent”), which vested based on either time (“time vesting awards”) or the achievement of certain performance and market conditions (“performance awards” and, together with the time vesting awards, the “pre-IPO awards”). In connection with the IPO, Topco Parent made in-kind distributions of restricted shares of our common stock to holders of pre-IPO awards as described in Note 15, “Stockholders' Equity”. The restricted shares of our common stock distributed in respect of pre-IPO time vesting awards vest through June 2025; expense related to these unvested awards will be recognized over the remaining vesting period. Expense attributable to the performance awards was recognized in its entirety in the year ended December 31, 2020 as the related performance conditions were considered probable of achievement and the implied service condition was met. Share-based compensation expense is recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss), primarily within “Selling, general and administrative expenses” at the grant date fair value over the requisite service period (one to four years for awards granted under the 2020 Plan and five years for time vesting pre-IPO awards on a straight-line basis). Fair value of the pre-IPO awards was estimated on the date of grant using a simulation-based option valuation model incorporating multiple and variable assumptions over time, including assumptions such as employee forfeitures, unit price volatility and dividend assumptions. We use the Black-Scholes option pricing model to measure the grant date fair value of stock options awarded under the 2020 Plan using certain valuation assumptions. Share-based compensation expense for all awards recognizes forfeitures as they occur.

Earnings (Loss) Per Share – In periods in which the Company has net income, earnings per share information is determined using the two-class method, which includes the weighted-average number of common shares outstanding during the period and securities that participate in dividends (“participating securities”). Our unvested restricted common stock distributed in respect of pre-IPO Class B-1 and B-2 awards have the right to receive non-forfeitable dividends or dividend equivalents if the Company declares dividends on its common stock. Under the two-class method, earnings are allocated to both common stock shares and participating securities based on their respective weighted-average shares outstanding for the period. Diluted

earnings (loss) per common share incorporates the dilutive effect of common stock equivalents on an average basis during the period, if dilutive, in which case the dilutive effect of such securities is calculated using the more dilutive of (a) the two-class method, or (b) treasury stock method, as applicable, to the potentially dilutive instruments. Unvested restricted common stock is not included in the weighted average common shares outstanding figure within earnings per share until the period in which the vesting condition is satisfied. In periods in which the Company has a net loss, the two-class method is not applicable because the pre-IPO Class B-1 and B-2 restricted stock awards do not participate in losses. Refer to Note 17, “Earnings (Loss) Per Share” for additional information.

Treasury Stock – The Company records repurchases of its own common stock at cost. Repurchased common stock is presented as a reduction of equity in the Consolidated Balance Sheets. The difference between the repurchase and reissue price of the Company’s own stock is added to or deducted from additional paid-in capital. The cost of Treasury Stock reissued is calculated using a weighted average cost method.

Commitments and Contingencies – Certain conditions may exist as of the date of the consolidated financial statements which may result in a loss to the Company but will only be resolved when one or more future events occur or fail to occur. Such liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties, settlement agreements, and other sources, are recorded when management assesses that it is probable that a future liability has been incurred and the amount can be reasonably estimated. Recoveries of costs from third parties, which management assesses as being probable of realization, are recorded to the extent related contingent liabilities are accrued. Legal costs incurred in connection with matters relating to contingencies are expensed in the period incurred. We record gain contingencies when realized.

Employee Benefits - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Letters of credit outstanding, amount	$ 16.0	$ 44.1
Period of actual funding requirements	5 years
Defined benefit pension plan \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Solvency payment as percent of market value	15.00%
United States
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 5.7	5.0	$ 4.3
Outside the U.S.
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 1.7	$ 1.2	$ 1.4

Related Parties	12 Months Ended
Related Parties	Dec. 31, 2023
Related Party Transactions [Abstract]
Related Parties	Related Parties We do business with a number of companies affiliated with Warburg Pincus and GTCR, which we refer to collectively as the “Sponsors.” For the year ended December 31, 2022, the Company recorded sales of $3.7 million to Curia Global (“Curia”), an affiliate of GTCR. Amounts due from Curia as of December 31, 2022 were $0.8 million. For the years ended December 31, 2023 and 2021, the Company had not engaged in any material related party transactions.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(e))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//850/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-6

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483326/850-10-50-1

+ Details

Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2023

Postemployment Benefits [Abstract]

Schedule of Net Benefit Costs

The components of net periodic benefit cost for the defined benefit plans were as follows:


Year ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Service cost	$	525	$	969	$	1,204
Interest cost	10,917		7,411		6,516
Expected return on plan assets	(16,108)		(14,421)		(14,370)
Amortization of net actuarial loss	—		—		1,079
Net periodic benefit	$	(4,666)	$	(6,041)	$	(5,571)

The components of net periodic benefit cost for the other benefit plans were as follows:


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
Service cost	$	9	$	16	$	28
Interest cost	398		284		268
Amortization of net actuarial gain	(197)		(171)		(34)
Net periodic benefit cost	$	210	$	129	$	262

Schedule of Defined Benefit Plan, Assumptions

The following weighted average assumptions were used in the determination of the projected benefit obligation and the net periodic benefit:


Year ended December 31,	2023		2022
Projected benefit obligation
Discount rate	4.65	%	5.19	%
Rate of compensation increase	3.00	%	3.00	%
Periodic benefit
Discount rate	5.19	%	3.01	%
Expected return on plan assets	6.50	%	5.00	%
Rate of compensation increase	3.00	%	3.00	%

The weighted average assumptions used to determine the projected benefit obligation and net periodic pension cost for these plans were as follows:


Year Ended December 31,	2023		2022
Projected benefit obligation:
Discount rate	4.65	%	5.19	%
Rate of compensation increase	3.00	%	3.00	%
Initial health care cost trend rate	7.00	%	7.00	%
Ultimate health care cost trend rate	4.00	%	4.00	%
Years until ultimate trend rate is reached	16		18
Benefit cost:
Discount rate	5.19	%	3.01	%
Rate of compensation increase	3.00	%	3.00	%

Schedule of Defined Benefit Plans Disclosures

The changes in the projected benefit obligation, fair value of plan assets, and the funded status of the plans are as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Change in projected benefit obligation:
Projected benefit obligation, as of beginning of the year	$	217,582	$	296,712
Service cost	681		1,118
Interest cost	10,917		7,411
Benefits paid	(12,305)		(12,207)
Actuarial loss (gain)	17,934		(59,378)

Foreign currency exchange rate changes	5,138		(16,074)

Projected benefit obligation, end of year	$	239,947	$	217,582

Change in fair value of plan assets:
Fair value of plan assets as of the beginning of the year	$	253,130	$	302,190
Actual return (loss) on plan assets	21,163		(20,038)
Benefits paid	(12,305)		(12,207)
Employer contributions	496		693
Employee contributions	156		149
Foreign currency exchange rate changes	5,784		(17,657)

Fair value of plan assets, end of year	$	268,424	$	253,130

Funded status at end of year	$	28,477	$	35,548

Accumulated benefit obligation, end of year	$	237,016	$	215,001

Expected future benefit payments from plan assets are as follows:


(thousands of U.S. dollars)
Year Ended December 31,
2024	$	14,066
2025	14,363
2026	14,651
2027	14,774
2028	14,911
2029 - 2033	75,755
	$	148,520

The changes in the projected benefit obligation and the funded status of the other post-retirement plans were as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Change in projected benefit obligation:
Projected benefit obligation	$	8,391	$	11,942
Service cost	9		16
Interest cost	398		284
Benefits paid	(665)		(590)
Actuarial loss (gain)	509		(2,775)
Plan participant contributions	129		146
Foreign currency exchange rate changes	193		(632)

Projected benefit obligation, end of year	$	8,964	$	8,391

Change in fair value of plan assets:
Fair value of plan assets as of the beginning of the year	$	481	$	478
Benefits paid	(183)		(181)
Employer contributions	216		216

Foreign currency exchange rate changes	11		(32)

Fair value of plan assets, end of year	$	525	$	481

Underfunded status at end of year	$	(8,439)	$	(7,910)

Accumulated benefit obligation, end of year	$	8,943	$	8,381

Based on the actuarial assumptions used to develop the Company’s benefit obligations as of December 31, 2023, the following benefit payments are expected to be made to plan participants:


(thousands of U.S. dollars)
Years ended December 31
2024	$	538
2025	549
2026	548
2027	575
2028	512
2029 - 2033	2,643
Total	$	5,365

Schedule of Net Funded Status

A reconciliation of the funded status to amounts recognized in the Consolidated Balance Sheets is as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Projected benefit obligation	$	239,947	$	217,582
Fair value of plan assets	268,424		253,130
Plan assets greater than projected benefit obligation (noncurrent assets)	28,477		35,548
Unrecognized net actuarial loss (gain)	11,429		(1,649)

A reconciliation of the funded status to the net plan liabilities recognized in the Consolidated Balance Sheets is as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Projected benefit obligation	$	8,964	$	8,391
Fair value of plan assets	525		481
Plan assets less than projected benefit obligation (noncurrent liabilities)	(8,439)		(7,910)
Unrecognized actuarial gains	(2,074)		(2,732)

Schedule of Amounts Recognized in Other Comprehensive Income (Loss)

The following table illustrates the amounts in accumulated other comprehensive (income) loss that have not yet been recognized as components of pension expense:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Net actuarial loss (gain)	$	11,429	$	(1,649)
Deferred income taxes	(2,919)		370
Accumulated other comprehensive loss (gain) – net of tax	$	8,510	$	(1,279)

The following table illustrates the amounts in accumulated other comprehensive income (loss) that have not yet been recognized as components of other benefit plan expense:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Net actuarial gain	$	(2,074)	$	(2,732)
Deferred income taxes	585		699
Accumulated other comprehensive income – net of tax	$	(1,489)	$	(2,033)

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates

Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. A one-percentage point change in assumed health care cost trend rates would have had the following impact on our consolidated financial statements in 2023:


(thousands of U.S. dollars)	1% Increase		1% Decrease
Change in net periodic benefit cost	$	25	$	(22)
Change in projected benefit obligation	596		(500)

Schedule of Allocation of Plan Assets

The weighted average asset allocation of the Company’s pension plans was as follows:


Asset Category	Target		2023		2022
Cash	0.0	%	0.7	%	0.4	%
Fixed income	54.0	%	43.7	%	43.1	%
Equities	27.0	%	34.0	%	33.4	%
Hedge funds	19.0	%	21.6	%	23.1	%
Total	100.0	%	100.0	%	100.0	%

Earnings (Loss) Per Share (Tables)

12 Months Ended

Dec. 31, 2023

Earnings Per Share [Abstract]

Schedule of Earnings (Loss) Per Share, Basic and Diluted

Our basic and diluted earnings (loss) per common share are calculated as follows:


	Year Ended December 31,
in thousands of U.S. dollars and share amounts (except per share amounts)	2023		2022		2021
Earnings (loss):
Net income (loss)	$	51,376	$	(233,570)	$	117,121
Less: Net income attributable to noncontrolling interests	—		—		239
Less: Allocation to participating securities	287		—		1,524
Net income (loss) attributable to Sotera Health Company common stockholders	$	51,089	$	(233,570)	$	115,358
Weighted Average Common Shares:
Weighted-average common shares outstanding - basic	281,008		280,096		279,228
Dilutive effect of potential common shares(a)	2,213		—		154
Weighted-average common shares outstanding - diluted	283,222		280,096		279,382
Earnings (loss) per Common Share:
Net income (loss) per common share attributable to Sotera Health Company common stockholders - basic	$	0.18	$	(0.83)	$	0.41
Net income (loss) per common share attributable to Sotera Health Company common stockholders - diluted	0.18		(0.83)		0.41

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

Diluted earnings per shares does not consider the following potential common shares as the effect would be anti-dilutive:


	Year Ended December 31,
in thousands of share amounts	2023	2022	2021
RSUs	291	2,467	4
Stock options	4,108	5,990	2,403
Total anti-dilutive securities	4,399	8,457	2,407

Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Provision (benefit) computed at federal statutory rate	$ 22,265	$ (51,053)	$ 36,872
State taxes, net of federal benefit	(2,889)	(20,359)	1,013
Valuation allowance	19,494	53,860	8,455
Global intangible low-tax income (“GILTI”)	4,861	1,427	2,103
Nondeductible share-based compensation	3,192	2,510	1,512
Foreign tax rate differential	10,595	8,335	8,005
Impact of rate changes on deferred tax balances	(92)	(1,184)	2,612
Tax holiday	(1,082)	(605)	(706)
Audit settlement	739	276	276
Tax credits	0	(172)	(248)
Other	(2,432)	(2,576)	(1,299)
Total provision (benefit) for income taxes	$ 54,651	$ (9,541)	$ 58,595

Share-Based Compensation - RSUs (Details)	12 Months Ended
Share-Based Compensation - RSUs (Details)	Dec. 31, 2023 $ / shares shares
Weighted- average Grant Date Fair Value
Ending balance (in dollars per share)	$ 2.77
RSUs
Number of Shares
Beginning balance (in shares) \| shares	2,482,435
Granted (in shares) \| shares	921,472
Forfeited (in shares) \| shares	(180,754)
Vested (in shares) \| shares	(924,317)
Ending balance (in shares) \| shares	2,298,836
Weighted- average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 13.09
Granted (in dollars per share)	16.95
Forfeited (in dollars per share)	12.09
Vested (in dollars per share)	15.37
Ending balance (in dollars per share)	$ 13.81

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities:
Net income (loss)	$ 51,376	$ (233,570)	$ 117,121
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation	76,577	64,000	64,160
Amortization of intangible assets	81,348	81,554	86,742
Impairment of investment in unconsolidated affiliate	0	9,613	0
Loss on extinguishment of debt	0	0	20,681
Deferred income taxes	3,449	(73,960)	(3,716)
Share-based compensation expense	32,238	21,211	13,870
Accretion expense	2,413	2,194	2,252
Unrealized foreign exchange loss (gain)	6,057	(3,984)	788
Unrealized loss (gain) on derivatives not designated as hedging instruments	(1,637)	2,977	(1,195)
Amortization of debt issuance costs	9,051	5,681	6,161
Other	(5,319)	(6,989)	(12,728)
Changes in operating assets and liabilities:
Accounts receivable	(21,724)	(12,555)	(15,509)
Inventories	(9,972)	14,441	(20,245)
Other current assets	4,003	(5,816)	(3,552)
Accounts payable	(5,333)	1,107	19,761
Accrued liabilities	3,500	20,595	1,596
Income taxes payable / receivable, net	924	(12,332)	10,103
Other liabilities	(1,733)	383	(369)
Other long-term assets	(238)	(4,589)	(4,376)
Net cash provided by (used in) operating activities	(147,732)	277,961	281,545
Investing activities:
Purchases of property, plant and equipment	(214,975)	(182,378)	(102,162)
Purchase of BioScience Laboratories, LLC, net of cash acquired	0	0	(13,530)
Purchase of mandatorily redeemable noncontrolling interest in Nelson Laboratories Fairfield, Inc.	0	0	(12,425)
Purchase of Regulatory Compliance Associates Inc., net of cash acquired	0	450	(31,015)
Other investing activities	69	32	(701)
Net cash used in investing activities	(214,906)	(181,896)	(159,833)
Financing activities:
Proceeds from revolving credit facility and long-term borrowings	500,000	200,000	0
Payment of revolving credit facility	(200,000)	0	0
Purchase of noncontrolling interests in China subsidiaries	0	0	(8,418)
Payments of debt issuance costs and prepayment premium	(25,645)	(31)	(6,792)
Payments of long-term borrowings	(2,500)	0	(100,000)
Shares withheld for employee taxes on equity awards	(4,089)	(393)	(1,434)
Other financing activities	(1,807)	(1,815)	(642)
Net cash provided by (used in) financing activities	265,959	197,761	(117,286)
Effect of exchange rate changes on cash and cash equivalents	2,039	(4,456)	44
Net increase (decrease) in cash and cash equivalents, including restricted cash	(94,640)	289,370	4,470
Cash and cash equivalents, including restricted cash, at beginning of period	396,294	106,924	102,454
Cash and cash equivalents, including restricted cash, at end of period	301,654	396,294	106,924
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	173,842	75,849	58,772
Cash paid during the period for income taxes, net of tax refunds received	50,210	75,496	52,007
Purchases of property, plant and equipment included in accounts payable	16,720	16,413	14,524
Illinois EO litigation settlement
Changes in operating assets and liabilities:
Litigation settlement	(407,712)	408,000	0
Georgia EO litigation settlement
Changes in operating assets and liabilities:
Litigation settlement	$ 35,000	$ 0	$ 0

Leases - Maturities (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Operating Leases
2024	$ 7,357
2025	5,505
2026	5,077
2027	3,999
2028	2,926
2029 and Thereafter	6,165
Total lease payments	31,029
Less imputed interest	(5,008)
Total lease liabilities	26,021
Finance Leases
2024	12,579
2025	5,767
2026	5,737
2027	5,893
2028	6,063
2029 and Thereafter	74,337
Total lease payments	110,376
Less imputed interest	(37,812)
Total lease liabilities	72,564
Total
2024	19,936
2025	11,272
2026	10,814
2027	9,892
2028	8,989
2029 and Thereafter	80,502
Total lease payments	141,405
Less imputed interest	(42,820)
Total lease liabilities	$ 98,585

Schedule II - Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2023

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

Schedule II - Valuation and Qualifying Accounts

Schedule II – Valuation and Qualifying Accounts

(in thousands)


Description	Balance at Beginning of Period		Charges (credits) to costs and expense(1)		Deductions(2)		Translation Adjustments(3)		Balance at End of Period

Year Ended December 31, 2023
Deducted from asset accounts:
Allowance for uncollectible accounts receivable	$	1,871	$	4,313	$	(1,502)	$	7	$	4,689
Deferred tax asset valuation allowance	105,600		19,682		—		153		125,435
Year Ended December 31, 2022
Deducted from asset accounts:
Allowance for uncollectible accounts receivable	$	1,287	$	1,009	$	(419)	$	(6)	$	1,871
Deferred tax asset valuation allowance	52,080		53,945		—		(425)		105,600
Year Ended December 31, 2021
Deducted from asset accounts:
Allowance for uncollectible accounts receivable	$	708	$	1,132	$	(408)	$	(145)	$	1,287
Deferred tax asset valuation allowance	43,765		8,455		—		(140)		52,080

(1)For the year ended December 31, 2023, certain charges were recorded as a reduction to revenue

(2)Uncollectible accounts written off, net of recoveries

(3)Change in foreign currency exchange rates

Segment and Geographic Information - Long-Lived Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total	$ 946,914	$ 774,527
United States
Segment Reporting Information [Line Items]
Total	494,793	413,887
Europe
Segment Reporting Information [Line Items]
Total	170,669	143,809
Canada
Segment Reporting Information [Line Items]
Total	181,628	140,761
Other
Segment Reporting Information [Line Items]
Total	$ 99,824	$ 76,070
Asia
Segment Reporting Information [Line Items]
Percent of total long-lived assets	5.00%	5.00%
Latin America
Segment Reporting Information [Line Items]
Percent of total long-lived assets	5.00%	5.00%

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 76.6	$ 64.3	$ 64.2
Capitalized interest	$ 12.2	$ 3.7	$ 1.1

Asset Retirement Obligations (“ARO”) - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation Disclosure [Abstract]
Depreciation expense	$ 0.4	$ 0.3	$ 0.4
Decommissioning obligation, letters of credit and surety bonds outstanding	$ 48.2	$ 54.1

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 43,411	$ 36,402
Work-in-process	471	584
Finished goods	4,670	276
Inventories, gross	48,552	37,262
Reserve for excess and obsolete inventory	(236)	(117)
Inventories, net	$ 48,316	$ 37,145

Employee Benefits

12 Months Ended

Dec. 31, 2023

Postemployment Benefits [Abstract]

Employee Benefits

Employee Retirement Benefits in the U.S.

We have a defined-contribution retirement plan that covers all U.S. employees upon date of hire. Contributions are directed by each participant into various investment options. Under this plan, we match participants’ contributions based on plan provisions. The Company’s contributions, which are expensed as incurred, were $5.7 million, $5.0 million, and $4.3 million for the years ended December 31, 2023, 2022 and 2021, respectively, and are recorded in the same line as the respective employee’s wages. Administrative expenses related to the plan are paid by the Company and are not material.

Employee Retirement Benefits Outside the U.S.

The Company participates in qualified supplemental retirement and savings plans in various countries outside the U.S. where we operate. Under these defined-contribution plans, funding and costs are generally based upon a predetermined percentage of employee compensation. The Company’s contributions, which are expensed as incurred and recorded in the same line as the respective employee’s wages, were $1.7 million, $1.2 million and $1.4 million for the years ended December 31, 2023, 2022 and 2021, respectively.

Defined Benefit Pension Plans

The Company also sponsors various post-employment benefit plans including, in certain countries outside the U.S., defined benefit and defined contribution plans, retirement compensation arrangements, and plans that provide extended health care coverage to retired employees, the majority of which relate to Nordion.

Defined Benefit Pension Plan

The following defined benefit pension plan disclosure relates to Nordion. All other foreign defined benefit pension plans are immaterial. The interest cost, expected return on plan assets and amortization of net actuarial loss are recorded in “Other income, net” and the service cost component is included in the same financial statement line item as the applicable employee’s

wages in the Consolidated Statements of Operations and Comprehensive Income (Loss). The components of net periodic benefit cost for the defined benefit plans were as follows:


Year ended December 31,
(thousands of U.S. dollars)	2023		2022		2021
Service cost	$	525	$	969	$	1,204
Interest cost	10,917		7,411		6,516
Expected return on plan assets	(16,108)		(14,421)		(14,370)
Amortization of net actuarial loss	—		—		1,079
Net periodic benefit	$	(4,666)	$	(6,041)	$	(5,571)

The following weighted average assumptions were used in the determination of the projected benefit obligation and the net periodic benefit:


Year ended December 31,	2023		2022
Projected benefit obligation
Discount rate	4.65	%	5.19	%
Rate of compensation increase	3.00	%	3.00	%
Periodic benefit
Discount rate	5.19	%	3.01	%
Expected return on plan assets	6.50	%	5.00	%
Rate of compensation increase	3.00	%	3.00	%

The changes in the projected benefit obligation, fair value of plan assets, and the funded status of the plans are as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Change in projected benefit obligation:
Projected benefit obligation, as of beginning of the year	$	217,582	$	296,712
Service cost	681		1,118
Interest cost	10,917		7,411
Benefits paid	(12,305)		(12,207)
Actuarial loss (gain)	17,934		(59,378)

Foreign currency exchange rate changes	5,138		(16,074)

Projected benefit obligation, end of year	$	239,947	$	217,582

Change in fair value of plan assets:
Fair value of plan assets as of the beginning of the year	$	253,130	$	302,190
Actual return (loss) on plan assets	21,163		(20,038)
Benefits paid	(12,305)		(12,207)
Employer contributions	496		693
Employee contributions	156		149
Foreign currency exchange rate changes	5,784		(17,657)

Fair value of plan assets, end of year	$	268,424	$	253,130

Funded status at end of year	$	28,477	$	35,548

Accumulated benefit obligation, end of year	$	237,016	$	215,001

All defined benefit pension plans are overfunded as of December 31, 2023 and December 31, 2022.

The funded status, measured as the difference between the fair value of the plan assets and the projected benefit obligation, are included in “Post-retirement assets” for overfunded plans and “Post-retirement obligations” for underfunded plans in the Consolidated Balance Sheets.

A reconciliation of the funded status to amounts recognized in the Consolidated Balance Sheets is as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Projected benefit obligation	$	239,947	$	217,582
Fair value of plan assets	268,424		253,130
Plan assets greater than projected benefit obligation (noncurrent assets)	28,477		35,548
Unrecognized net actuarial loss (gain)	11,429		(1,649)

The following table illustrates the amounts in accumulated other comprehensive (income) loss that have not yet been recognized as components of pension expense:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Net actuarial loss (gain)	$	11,429	$	(1,649)
Deferred income taxes	(2,919)		370
Accumulated other comprehensive loss (gain) – net of tax	$	8,510	$	(1,279)

We do not expect to reclassify any of the net actuarial loss in accumulated other comprehensive income to net periodic pension cost in the next twelve months.

The weighted average asset allocation of the Company’s pension plans was as follows:


Asset Category	Target		2023		2022
Cash	0.0	%	0.7	%	0.4	%
Fixed income	54.0	%	43.7	%	43.1	%
Equities	27.0	%	34.0	%	33.4	%
Hedge funds	19.0	%	21.6	%	23.1	%
Total	100.0	%	100.0	%	100.0	%

The Company maintains target allocation percentages among various asset classes based on investment policies established for the pension plans, which are designed to maximize the total rate of return (income and appreciation) after inflation, within the limits of prudent risk taking, while providing for adequate near-term liquidity for benefit payments. Such investment strategies have adopted an equity-based philosophy to achieve their long-term investment goals by investing in assets that often have uncertain returns, such as Canadian and other foreign equities, and non-government bonds, although, the Company also attempts to reduce the overall level of risk by diversifying the asset classes and further diversifying within each individual asset class.

The Company’s expected return on asset assumptions are derived from studies conducted by actuaries and investment advisors. The studies include a review of anticipated future long-term performance of individual asset classes and consideration of the appropriate asset allocation strategy given the anticipated requirements of the plans to determine the average rate of earnings expected on the funds invested to provide for the pension plans benefits. While the study considers recent fund performance and historical returns, the assumption is primarily a long-term, prospective rate.

Valuation Methodologies

Below is a description of the composition and valuation methodologies for pension plan assets. Refer to the discussion of fair value hierarchy in Note 21, “Financial Instruments and Financial Risk”.

Cash and cash equivalents – Consists of deposits with financial institutions and other short-term highly liquid investments with an original maturity of three months or less. Cash and cash equivalents are categorized as Level 1 instruments in the fair value hierarchy.

Fixed income securities, equity securities and hedge fund assets - These assets are invested in managed funds that are measured at fair value using the net asset value per share practical expedient and, therefore, are not categorized in the fair value hierarchy.

Expected future benefit payments from plan assets are as follows:


(thousands of U.S. dollars)
Year Ended December 31,
2024	$	14,066
2025	14,363
2026	14,651
2027	14,774
2028	14,911
2029 - 2033	75,755
	$	148,520

Other benefit plans

Other benefit plans disclosed below relate to Nordion and include a supplemental retirement arrangement, a retirement and termination allowance, and post-retirement benefit plans, which include contributory health and dental care benefits and contributory life insurance coverage. All non-pension post-employment benefit plans are unfunded. All other non-pension post-employment benefit plans are immaterial.

The interest cost and amortization of net actuarial (gain) loss are recorded in “Other income, net” and the service cost component is included in the same financial statement line item as the applicable employee’s wages in the Consolidated Statements of Operations and Comprehensive Income (Loss). The components of net periodic benefit cost for the other benefit plans were as follows:


(thousands of U.S. dollars)
Year Ended December 31,	2023		2022		2021
Service cost	$	9	$	16	$	28
Interest cost	398		284		268
Amortization of net actuarial gain	(197)		(171)		(34)
Net periodic benefit cost	$	210	$	129	$	262

The weighted average assumptions used to determine the projected benefit obligation and net periodic pension cost for these plans were as follows:


Year Ended December 31,	2023		2022
Projected benefit obligation:
Discount rate	4.65	%	5.19	%
Rate of compensation increase	3.00	%	3.00	%
Initial health care cost trend rate	7.00	%	7.00	%
Ultimate health care cost trend rate	4.00	%	4.00	%
Years until ultimate trend rate is reached	16		18
Benefit cost:
Discount rate	5.19	%	3.01	%
Rate of compensation increase	3.00	%	3.00	%


(thousands of U.S. dollars)	1% Increase		1% Decrease
Change in net periodic benefit cost	$	25	$	(22)
Change in projected benefit obligation	596		(500)

The changes in the projected benefit obligation and the funded status of the other post-retirement plans were as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Change in projected benefit obligation:
Projected benefit obligation	$	8,391	$	11,942
Service cost	9		16
Interest cost	398		284
Benefits paid	(665)		(590)
Actuarial loss (gain)	509		(2,775)
Plan participant contributions	129		146
Foreign currency exchange rate changes	193		(632)

Projected benefit obligation, end of year	$	8,964	$	8,391

Change in fair value of plan assets:
Fair value of plan assets as of the beginning of the year	$	481	$	478
Benefits paid	(183)		(181)
Employer contributions	216		216

Foreign currency exchange rate changes	11		(32)

Fair value of plan assets, end of year	$	525	$	481

Underfunded status at end of year	$	(8,439)	$	(7,910)

Accumulated benefit obligation, end of year	$	8,943	$	8,381

All other post-retirement benefit pension plans are underfunded as of December 31, 2023 and 2022.

A reconciliation of the funded status to the net plan liabilities recognized in the Consolidated Balance Sheets is as follows:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Projected benefit obligation	$	8,964	$	8,391
Fair value of plan assets	525		481
Plan assets less than projected benefit obligation (noncurrent liabilities)	(8,439)		(7,910)
Unrecognized actuarial gains	(2,074)		(2,732)

The other benefit plan liabilities are presented on the Consolidated Balance Sheets as “Post retirement obligations.”

The following table illustrates the amounts in accumulated other comprehensive income (loss) that have not yet been recognized as components of other benefit plan expense:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Net actuarial gain	$	(2,074)	$	(2,732)
Deferred income taxes	585		699
Accumulated other comprehensive income – net of tax	$	(1,489)	$	(2,033)

Based on the actuarial assumptions used to develop the Company’s benefit obligations as of December 31, 2023, the following benefit payments are expected to be made to plan participants:


(thousands of U.S. dollars)
Years ended December 31
2024	$	538
2025	549
2026	548
2027	575
2028	512
2029 - 2033	2,643
Total	$	5,365

The Company currently has no funding requirements as the Nordion pension plan has a going concern surplus as of January 1, 2023, as defined by Canadian federal regulation, which require solvency testing on defined benefit pension plans on an annual basis.

The Company may obtain a qualifying letter of credit for solvency payments, up to 15% of the market value of solvency liabilities as determined on the valuation date, instead of cash payment into the pension fund. As of December 31, 2023 and 2022, we had letters of credit outstanding relating to the defined benefit plans totaling $16.0 million and $44.1 million, respectively. The actual funding requirements over the five-year period will be dependent on subsequent annual actuarial valuations. These amounts are estimates, which may change with actual investment performance, changes in interest rates, any pertinent changes in Canadian government regulations, and any voluntary contributions.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480482/715-20-55-17

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (l)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//715/tableOfContent

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480126/715-20-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480266/715-60-50-3

+ Details

Acquisitions (Details) - USD ($) $ in Thousands	Nov. 04, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill		$ 1,111,190	$ 1,101,768	$ 1,120,320
Regulatory Compliance Associates Inc. (“RCA”)
Business Acquisition [Line Items]
Purchase price	$ 30,600
Cash acquired from acquisition	$ 600
Goodwill		25,300
Regulatory Compliance Associates Inc. (“RCA”) \| Customer relationships
Business Acquisition [Line Items]
Finite-lived intangibles		$ 6,400

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References + Details

Prepaid Expenses and Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Deferred Costs, Capitalized, Prepaid, and Other Assets

Prepaid expenses and other current assets consisted of the following:


(thousands of U.S. dollars)
As of December 31,	2023		2022
Prepaid taxes	$	4,129	$	26,598
Prepaid business insurance	7,174		9,964
Prepaid rent	1,150		998
Customer contract assets	17,785		19,777
Insurance and indemnification receivables	—		3,724
Current deposits	715		660
Prepaid maintenance contracts	422		324
Value added tax receivable	4,306		1,640
Prepaid software licensing	2,503		1,832
Stock supplies	3,669		3,656
Embedded derivatives	1,225		2,721
Other	10,768		9,101
Prepaid expenses and other current assets	$	53,846	$	80,995

Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Roll Forward]
Beginning balance	$ 1,101,768	$ 1,120,320
Changes due to foreign currency exchange rates	9,422	(23,197)
Ending balance	1,111,190	1,101,768
RCA
Goodwill [Roll Forward]
RCA acquisition measurement period adjustments		4,645
Sterigenics
Goodwill [Roll Forward]
Beginning balance	657,458	660,743
Changes due to foreign currency exchange rates	2,430	(3,285)
Ending balance	659,888	657,458
Sterigenics \| RCA
Goodwill [Roll Forward]
RCA acquisition measurement period adjustments		0
Nordion
Goodwill [Roll Forward]
Beginning balance	270,966	288,905
Changes due to foreign currency exchange rates	5,963	(17,939)
Ending balance	276,929	270,966
Nordion \| RCA
Goodwill [Roll Forward]
RCA acquisition measurement period adjustments		0
Nelson Labs
Goodwill [Roll Forward]
Beginning balance	173,344	170,672
Changes due to foreign currency exchange rates	1,029	(1,973)
Ending balance	$ 174,373	173,344
Nelson Labs \| RCA
Goodwill [Roll Forward]
RCA acquisition measurement period adjustments		$ 4,645

- Definition

+ References + Details

Long-Term Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Gross Amount	$ 2,260,600	$ 1,963,550
Gross Amount	5,000	200,450
Gross Amount	2,255,600	1,763,100
Unamortized Debt Issuance Costs	(9,222)	(5,471)
Less current portion	(76)	(3,331)
Unamortized Debt Issuance Costs	(9,146)	(2,140)
Unamortized Debt Discount	(22,907)
Unamortized Debt Discount	(127)	0
Unamortized Debt Discount	(22,780)	(13,845)
Net Amount	2,228,471	1,944,234
Less current portion	4,797	197,119
Long-term debt	2,223,674	1,747,115
Revolving Credit Facility
Debt Instrument [Line Items]
Unamortized Debt Discount		0
Senior Secured Credit Facilities \| Revolving Credit Facility
Debt Instrument [Line Items]
Gross Amount		200,000
Unamortized Debt Issuance Costs		(3,328)
Long-term debt		196,672
Secured Debt \| Term loan, due 2026
Debt Instrument [Line Items]
Gross Amount	1,763,100	1,763,100
Unamortized Debt Issuance Costs	(1,606)	(2,140)
Unamortized Debt Discount	(10,298)	(13,845)
Net Amount	1,751,196
Long-term debt		1,747,115
Secured Debt \| Term loan B, due 2026
Debt Instrument [Line Items]
Gross Amount	497,500
Unamortized Debt Issuance Costs	(7,616)
Unamortized Debt Discount	(12,609)
Net Amount	$ 477,275
Other long-term debt
Debt Instrument [Line Items]
Gross Amount		450
Unamortized Debt Issuance Costs		(3)
Unamortized Debt Discount		0
Long-term debt		$ 447

Revenue Recognition (Tables)

12 Months Ended

Dec. 31, 2023

Revenue from Contract with Customer [Abstract]

Schedule of Disaggregation of Revenue

The following table shows disaggregated net revenues from contracts with external customers by timing of revenue and by segment for the years ended December 31, 2023, 2022 and 2021:


	Year Ended December 31, 2023
	Sterigenics		Nordion		Nelson Labs		Consolidated
Point in time	$	667,130	$	153,747	$	—	$	820,877
Over time	—		6,712		221,699		228,411
Total	$	667,130	$	160,459	$	221,699	$	1,049,288


	Year Ended December 31, 2022
	Sterigenics		Nordion		Nelson Labs		Consolidated
Point in time	$	626,646	$	147,499	$	—	$	774,145
Over time	—		6,140		223,402		229,542
Total	$	626,646	$	153,639	$	223,402	$	1,003,687


	Year Ended December 31, 2021
	Sterigenics		Nordion		Nelson Labs		Consolidated
Point in time	$	571,829	$	139,135	$	—	$	710,964
Over time	—		1,372		219,142		220,514
Total	$	571,829	$	140,507	$	219,142	$	931,478

Leases - Term and Rate (Details)	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Weighted-average remaining lease term, Operating leases	5 years 8 months 12 days	4 years 6 months
Weighted-average remaining lease term,Finance leases	14 years	14 years
Weighted-average discount rate, Operating leases	5.92%	5.88%
Weighted-average discount rate, Finance leases	5.76%	5.48%

Income Taxes - Schedule of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
U.S.	$ (100,635)	$ (418,308)	$ 5,092
Foreign	206,662	175,197	170,624
Income (loss) before income taxes	$ 106,027	$ (243,111)	$ 175,716

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(11))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
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+ Details

Income Taxes - Summary of Income Tax Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits, beginning of year	$ 0	$ 116
Additions related to current year	0	0
Reductions related to prior years	0	(116)
Settlements	0	0
Gross unrecognized tax benefits, end of period	$ 0	$ 0

Segment and Geographic Information - Additional Information (Details) - segment	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting [Abstract]
Number of operating segments	3
Number of reportable segments	3
Operating Segments \| Nordion \| Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Customer One
Segment Reporting Information [Line Items]
Percentage	20.10%	17.70%	15.10%
Operating Segments \| Nordion \| Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Customer Two
Segment Reporting Information [Line Items]
Percentage	14.80%	13.60%	12.70%
Operating Segments \| Nordion \| Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Customer Three
Segment Reporting Information [Line Items]
Percentage	13.90%	11.20%	11.50%
Operating Segments \| Nordion \| Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Customer Four
Segment Reporting Information [Line Items]
Percentage		10.70%	11.10%
Operating Segments \| Nordion \| Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Customer Five
Segment Reporting Information [Line Items]
Percentage		10.20%

Significant Accounting Policies - Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Undepreciated software costs	$ 7,900	$ 3,400
Property, Plant and Equipment [Line Items]
Undepreciated software costs	7,900	3,400
Depreciation	$ 76,577	64,000	$ 64,160
Co-60
Property, Plant and Equipment [Line Items]
Useful life	20 years
Software purchases and software development \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	1 year
Software purchases and software development \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	5 years
Buildings and building improvements \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	15 years
Buildings and building improvements \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	44 years
Machinery and equipment \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Machinery and equipment \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	30 years
Leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	2 years
Leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	20 years
Furniture and fixtures \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Furniture and fixtures \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	10 years
Computer hardware and software
Property, Plant and Equipment [Line Items]
Depreciation	$ 3,300	$ 2,200	$ 2,600
Computer hardware and software \| Minimum
Property, Plant and Equipment [Line Items]
Useful life	1 year
Computer hardware and software \| Maximum
Property, Plant and Equipment [Line Items]
Useful life	7 years

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2023
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation – Sotera Health Company (also referred to herein as the “Company,” “we,” “our,” “us” or “its”), is a leading global provider of mission-critical end-to-end sterilization solutions, lab testing and advisory services for the healthcare industry with operations primarily in the Americas, Europe and Asia. The accompanying consolidated financial statements include the assets, liabilities, operating results, and cash flows of the Company and its wholly owned subsidiaries prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). We operate and report in three segments, Sterigenics, Nordion and Nelson Labs. We describe our reportable segments in Note 22, “Segment and Geographic Information”. All intercompany balances and transactions have been eliminated in consolidation. Noncontrolling interests represented the noncontrolling stockholders’ proportionate share of the total equity in the Company’s consolidated subsidiaries. In the second quarter of 2021, we purchased the outstanding noncontrolling interests of 15% and 33% of our two China subsidiaries. Prior to our acquisition of the noncontrolling interests in our two subsidiaries in China, we consolidated the results of operations of these subsidiaries with our results of operations and reflected the noncontrolling interest on our Consolidated Statements of Operations and Comprehensive Income (Loss) as “Net income attributable to noncontrolling interests.” In July 2020, we acquired a 60% equity ownership interest in a joint venture to construct an E-beam facility in Alberta, Canada in connection with our acquisition of Iotron Industries Canada, Inc. (“Iotron”). Our equity ownership in the joint venture was determined to be an investment in a variable interest entity (“VIE”). The investment was not consolidated as the Company concluded that it was not the primary beneficiary of the VIE. The Company accounted for the joint venture using the equity method. The investment was reflected within “Investment in unconsolidated affiliates” on the Consolidated Balance Sheets. During the year ended December 31, 2022, we identified certain events and circumstances that indicated a decline in value of our investment in this joint venture that was other-than-temporary. Consequently, in the second quarter of 2022, we wrote down the investment in the joint venture to its fair value of $0, resulting in an impairment charge of approximately $9.6 million. In February 2023, we entered into a Share Purchase Agreement to transfer our equity ownership interest to the joint venture partner, thereby terminating our equity ownership interest.
Use of Estimates	Use of Estimates – In preparing our consolidated financial statements in conformity with U.S. Generally Accepted Accounting Principles (“GAAP”), we make estimates and assumptions that affect the amounts reported and the accompanying notes. We regularly evaluate the estimates and assumptions used and revise them as new information becomes available. Actual results may vary from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents – We consider all highly liquid investments purchased with an original maturity of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents may include various deposit accounts and money market funds.
Accounts Receivable	Accounts Receivable - Accounts receivable consists of amounts billed and currently due from customers. The amounts due are stated net of the allowance for uncollectible accounts. The Company maintains an allowance for uncollectible receivables to provide for the estimated amount of receivables that will not be collected.
Allowance for Uncollectible Accounts Receivable	Allowance for Uncollectible Accounts Receivable – We maintain an allowance for uncollectible accounts receivable for estimated losses in the collection of amounts owed to us by customers. We estimate the allowance based on analyzing a number of factors, including amounts written off historically, customer payment practices, customer financial information and credit ratings, current market conditions as well as the expected future economic conditions that may impact the collection of accounts receivable. We also analyze significant customer accounts on a regular basis and record a specific allowance when we become aware of a specific customer’s inability to pay. We generally do not charge interest on accounts receivable or require collateral from our customers. We record write-offs against the allowance for uncollectible accounts receivable when all reasonable efforts for collection have been exhausted. As a result, the related accounts receivable are reduced to an amount that we reasonably believe is collectible. These analyses require judgment. If the financial condition of our customers worsens, or economic conditions change, we may be required to make changes to our allowance for uncollectible accounts receivable.
Inventories	Inventories – Inventories as of December 31, 2023 and 2022 are held at Nordion. Inventories are stated at the lower of cost or net realizable value. Cost of material, labor, and manufacturing overhead are determined using standard cost, which approximates average cost. We review inventory on an ongoing basis, considering factors such as deterioration and obsolescence. We record a reserve for excess and obsolete inventory, which was immaterial at December 31, 2023 and 2022, when the facts and circumstances indicate that particular inventories will not be usable. If future market conditions vary from those projected, and our estimates prove to be inaccurate, we may be required to write-down inventory values and record an adjustment to cost of revenues.
Property, Plant, and Equipment	Property, Plant, and Equipment – Property, plant, and equipment is carried at cost, or initially at fair value if acquired in an acquisition, less accumulated depreciation and amortization. Except for Co-60, a radioactive isotope used in gamma radiation sterilization, all property, plant, and equipment depreciation is computed using the straight-line method over estimated useful lives. Leasehold improvements are amortized over their estimated useful lives or the term of the related lease, whichever is shorter. Co-60 is amortized using an accelerated method, which relates to the natural radioactive decay of the isotope over its estimated useful life which is approximately twenty years. Amortization of Co-60 is included within depreciation expense as a cost of revenue. Expenditures for major software purchases and software developed for internal use are capitalized and depreciated using the straight-line method over the estimated useful lives of the related assets, which are generally one to five years. From time to time, we build or expand facilities. The cost of construction of these facilities is reflected as construction-in-progress until the asset is ready for its intended use, at which time the costs are reclassified to the appropriate depreciable category of property, plant, and equipment and depreciation commences. Fixed asset projects requiring one or more years to complete construction qualify for capitalization of interest costs in accordance with our policy. Interest related to property, plant and equipment projects with a construction period of less than one year are not capitalized and are immaterial. Repairs and maintenance costs that do not extend the useful life of an asset are expensed as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation is removed from the Consolidated Balance Sheets, and the resulting gain or loss is reflected as a component of operating income.
Long-Lived Assets Other than Goodwill	Long-Lived Assets Other than Goodwill – We review long-lived assets, including finite-lived intangibles for impairment whenever events or circumstances indicate that the carrying amount of the asset or asset group may be impaired. Events or circumstances which would result in an impairment assessment include operating losses, a significant change in the use of an asset or asset group, or the planned disposal or sale of the asset or asset group. The asset or asset group would be considered impaired when the future net undiscounted cash flows generated by the asset or asset group are less than its carrying value. An impairment loss would be recognized based on the amount by which the carrying value of the asset or asset group exceeds its estimated fair value.
Leases	Leases – We determine if an agreement contains a lease and classify our leases as operating or finance at the lease commencement date. Leases with an initial term of twelve months or less are recognized as lease expense on a straight-line basis over the lease term and are not recorded on the Consolidated Balance Sheets. Non-lease components are accounted for separately from the lease components for all asset classes. Finance leases are those in which we will pay substantially all the underlying asset’s fair value or will use the asset for all or a major part of its economic life, including circumstances in which we will ultimately own the asset. Lease assets arising from finance leases are included in “Property, plant and equipment, net” and the liabilities are included in “Finance lease obligations” on the Consolidated Balance Sheets. For finance leases, we recognize interest expense using the effective interest method and we recognize amortization expense on the lease asset over the shorter of the lease term or the useful life of asset. Finance leases are accounted for as if the assets were owned and financed, with associated expense recognized in “Interest expense, net” and “Cost of revenues” or “Selling, general and administrative expenses” within the Consolidated Statements of Operations and Comprehensive Income (Loss) depending on the nature of the underlying asset. Operating lease assets and liabilities are recognized at the commencement date of the lease based on the present value of lease payments over the lease term. Lease assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. As most leases do not provide an implicit interest rate, we estimate an incremental borrowing rate to determine the present value of lease payments. Our estimated incremental borrowing rate reflects a secured rate based on recent debt issuances, our estimated credit rating, and lease term. We recognize operating lease costs on a straight-line basis over the term of the lease in “Cost of revenues” or “Selling, general and administrative expenses” on the Consolidated Statements of Operations and Comprehensive Income (Loss) depending on the nature of the underlying asset. We lease certain facilities and equipment under various non-cancelable leases. Most of our real property leases provide for renewal periods and rent escalations and stipulate that we pay taxes, maintenance, and certain other operating expenses applicable to the leased premises.
Goodwill and Other Indefinite-Lived Intangibles	Goodwill and Other Indefinite-Lived Intangibles – Goodwill and other indefinite-lived intangible assets, primarily certain regulatory licenses and tradenames, are tested for impairment annually as of October 1. If circumstances change during interim periods between annual tests that would indicate that the carrying amount of such assets may not be recoverable, the Company tests such assets at an interim date for impairment. Factors that necessitate an interim impairment assessment include prolonged negative industry or economic trends and significant underperformance relative to historical or projected future operating results. We performed a quantitative assessment of all reporting units (Sterigenics, Nordion and Nelson Labs) as of October 1, 2023. The fair value of each reporting unit was calculated using a discounted cash flow analysis which was dependent on subjective market participant assumptions determined by management. We further corroborated these discounted cash flow analyses utilizing a market approach to determine the estimated enterprise fair value. Assumptions used in the analyses included discount rates, revenue growth rates and projected operating cash flows. Estimates of future cash flows are based upon relevant data at a point-in-time, are subject to change, and could vary from actual results. The estimated fair value of each reporting unit exceeded its carrying amount by a sufficient margin to support a positive assertion that goodwill is not impaired. We performed a qualitative impairment assessment to evaluate any potential impairment to the indefinite-lived intangible assets. We considered significant events and circumstances that could affect the significant inputs used to determine the estimated fair value of the indefinite-lived intangible assets, and determined, after considering the totality of evidence that it is not more likely than not that the indefinite-lived intangible assets are impaired. There have been no other significant events or circumstances that occurred since the annual assessment date of October 1 that would change the conclusions reached above.
Derivative Instruments	Derivative Instruments – We may enter into derivative instruments and hedging activities to manage, where possible and economically efficient, commodity price risk, foreign currency exchange rate risk and interest rate risk related to borrowings. We also have identified embedded derivatives in certain supply and customer contracts. Certain interest rate derivatives are designated as cash flow hedges allowing for changes in fair value to be recorded through “Other comprehensive income (loss)”. Amounts in accumulated other comprehensive income (loss) will be reclassified into earnings in the same periods during which the hedged transaction affects earnings and are presented in “Interest expense, net” within the Consolidated Statements of Operations and Comprehensive Income (Loss). Derivatives not designated as hedges are recorded at fair value on the Consolidated Balance Sheets, with any changes in the value being recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss) in the same line item as the corresponding hedged item. We classify cash flows from derivative instruments and hedging activities as cash flows from operating activities in the Consolidated Statements of Cash Flows. To the extent derivative arrangements are with the same counterparty and contractual right of offset exists under applicable master agreements, we offset assets and liabilities for reporting on the Consolidated Balance Sheets.
Pension, Post-Retirement and Other Post-Employment Benefit Plans	Pension, Post-Retirement and Other Post-Employment Benefit Plans – We sponsor a defined-contribution retirement plan that covers substantially all U.S. employees. We also sponsor various post-employment benefit plans at our Nordion business in Canada, including defined benefit and defined contribution pension plans, retirement compensation arrangements and plans that provide extended health care coverage to retired employees. In addition, we provide other benefit plans at our foreign subsidiaries, including a supplemental retirement arrangement, a retirement and termination allowance and post-retirement benefit plans, which include contributory healthcare benefits and contributory life insurance coverage. All non-pension post-employment benefit plans are unfunded. These costs and obligations are affected by assumptions including the discount rate, the expected long-term rate of return on plan assets, the annual rate of change in compensation for eligible employees, estimated changes in costs of healthcare benefits, and other demographic and economic factors. We review the assumptions used on an annual basis. We recognize the over/under funded status of defined benefit pension and post-retirement benefits plans in our Consolidated Balance Sheets. This amount is measured as the difference between the fair value of plan assets and the projected benefit obligation. Changes in the funded status of the plans are recorded in other comprehensive income (loss) in the year they occur. We measure plan assets and obligations as of the balance sheet date. We provide additional information about our pension and other post-retirement benefits plans in Note 12, “Employee Benefits”. Amortization of net gain or loss included in accumulated other comprehensive income (loss) shall be reclassified to net periodic pension cost if, as of the beginning of the year, that gain or loss exceeds 10% of the greater of the projected benefit obligation (“PBO”) or the market related value of the plan assets (the ‘corridor’). As most of the plan’s participants are no longer actively accruing benefits, the average remaining life expectancy is used.
Asset Retirement Obligations	Asset Retirement Obligations (“ARO”) – ARO are legal obligations associated with the retirement of long-lived assets or the exit of a leased facility. We recognize a liability for an ARO in the period in which it is incurred if a reasonable estimate of fair value can be made, and the associated asset retirement costs are then capitalized as part of the carrying amount of the long-lived asset. We lease various facilities where sterilization and ionization services are performed. Under the lease agreements, we are required to return the facilities to their original condition and to perform decommissioning activities. In addition, certain of our owned facilities are required to be decommissioned when we vacate the facility. Accretion expense is recognized in cost of revenues in the Consolidated Statements of Operations and Comprehensive Income (Loss) over time as the discounted liability is accreted to its expected settlement value.
Debt Issuance Costs, Premiums and Discounts	Debt Issuance Costs, Premiums and Discounts – We have incurred costs in connection with obtaining financing as well as premiums and discounts associated with our long-term debt. The portion of these fees that are capitalized are recorded as a reduction of debt on the Consolidated Balance Sheets and amortized into interest expense over the term of the debt agreement. Debt issuance costs associated with the Company’s revolving credit facilities are classified as assets unless there are outstanding borrowings under such arrangements.
Concentration of Credit Risk, Other Risks and Uncertainties	Concentration of Credit Risk, Other Risks and Uncertainties – We maintain cash and cash equivalents in the form of demand deposits in accounts with major financial institutions in the U.S. and in countries where our subsidiaries operate. Deposits in these institutions may exceed amounts of insurance provided on such accounts. We have not experienced any losses on our deposits of cash and cash equivalents.
Income Taxes	Income Taxes –We use the liability method of accounting for income taxes whereby we recognize deferred tax assets and liabilities for the future tax consequences of temporary differences between the tax bases of assets and liabilities and their reported amounts in the consolidated financial statements. Deferred tax assets will be reduced by a valuation allowance if, based on management’s estimate, it is more likely than not that a portion of the deferred tax assets will not be realized in a future period. The estimates used in the recognition of deferred tax assets are subject to revision in future periods based on new facts and circumstances. We determine whether it is more likely than not that a tax position will be sustained upon examination, including resolution of related appeals or litigation processes, based on the technical merits of the position. In evaluating whether a tax position has met the more-likely-than-not recognition threshold, we presume that the position will be examined by the appropriate taxing authority and that the taxing authority will have full knowledge of all relevant information. A tax position that meets the more-likely-than-not recognition threshold is measured at the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. Determining what constitutes an individual tax position and whether the more-likely-than-not recognition threshold is met for a tax position are matters of judgment based on the individual facts and circumstances of that position evaluated in light of all available evidence. We review and adjust tax estimates periodically because of ongoing examinations by, and settlements with, the various taxing authorities, as well as changes in tax laws, regulations, and precedent. We are subject to a tax on Global Intangible Low Taxed Income (“GILTI”) which we record as a period cost. Our policy is to recognize interest and penalties related to income tax matters as a component of the provision for income taxes in our Consolidated Statements of Operations and Comprehensive Income (Loss).
Foreign Currency Translation and Gains/Losses	Foreign Currency Translation – The functional currency of our foreign subsidiaries is generally the local currency. Accordingly, assets and liabilities are generally translated into U.S. dollars at the current rates of exchange as of the balance sheet date, and revenues and expenses are translated using weighted-average rates prevailing during the period. Adjustments from foreign currency translation are included as a separate component of accumulated other comprehensive income (loss). Gains or losses arising from foreign currency transactions are recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) as foreign exchange loss (gain). The Company routinely enters into foreign currency forward contracts to manage foreign currency exchange rate risk of our intercompany loans in certain of our international subsidiaries and non-functional currency assets and liabilities. The foreign currency forward contracts expire on a monthly basis. For the years ended December 31, 2023, 2022 and 2021, foreign exchange loss related primarily to short-term losses (offset by short-term gains) on sales denominated in currencies other than the functional currency of our operating entities.
Revenue Recognition	Revenue Recognition – Revenue is recognized when control of promised goods or services is transferred to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those goods or services. The majority of our sales agreements contain performance obligations satisfied at a point-in-time when control of promised goods or services have transferred to our customers. Sales recognized over time are generally accounted for using an input measure to determine progress completed as of the end of the period. Refunds, returns, warranties and other related obligations are not material to any of our segments and we do not incur material incremental costs to secure customer contracts. Our Sterigenics segment provides outsourced terminal sterilization and irradiation services for the medical device, pharmaceutical, food safety and advanced applications markets. We typically have multiyear service contracts with our significant customers, and these sales contracts are primarily based on customers’ purchase orders. Given the relatively short turnaround times, performance obligations are generally satisfied at a point-in-time upon the completion of sterilization or irradiation processing and approval by our quality assurance process. Sterigenics segment revenues are included in service revenues in our Consolidated Statements of Operations and Comprehensive Income (Loss). Our Nordion segment is a global provider of Co-60 and gamma irradiation systems, which are key components to the gamma sterilization process. Revenue from the sale of Co-60 sources is recognized as product revenue at a point-in-time upon satisfaction of our performance obligations for delivery of existing sources. Revenue from the sale of gamma irradiation systems is recognized as product revenue over time using an input measure of costs incurred and is immaterial to the overall business. Revenues from Co-60 installation and disposal and gamma irradiation systems refurbishments and installations are recognized as service revenue. Our Nelson Labs segment provides outsourced microbiological and analytical chemistry testing and advisory services for the medical device and pharmaceutical industries. We provide our customers mission-critical lab testing services, which assess the product quality, effectiveness, patient safety and end-to-end sterility of products. These services are necessary for our customers’ regulatory approvals, product releases and ongoing product performance evaluations. Nelson Labs services are generally provided on a fee-for-service or project basis, and we recognize revenues over time using an input measure of time incurred to determine progress completed at the end of the period. Nelson Labs segment revenues are included in service revenues in our Consolidated Statements of Operations and Comprehensive Income (Loss). We do not capitalize sales commissions because substantially all of our sales commission programs have an amortization period of one year or less. Furthermore, costs to fulfill a contract are not material. Provisions for discounts, rebates to customers, and other adjustments are provided for as reductions in net revenues in the period the related sale is recorded. Shipping and handling charges billed to customers are included in net revenues, and the related shipping and handling costs are included in cost of net revenues on the Consolidated Statements of Operations and Comprehensive Income (Loss). Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, that are collected by us from a customer, are excluded from net revenue. Payment terms vary by the type and location of the customer and the products or services offered. Generally, the time between when revenue is recognized and when payment is due is not significant. We do not evaluate whether the selling price contains a financing component for contracts that have a duration of less than one year.
Share-Based Compensation	Share-Based Compensation – Equity-based awards issued to employees under the Sotera Health Company 2020 Omnibus Incentive Plan (“2020 Plan”) include restricted stock units (“RSUs”) and stock options that vest over time. Prior to our initial public offering (the “IPO” as described in Note 15, “Stockholders' Equity”), equity-based awards were issued to employees and non-employee directors in the form of partnership interests in our predecessor, Sotera Health Topco Parent, L.P. (“Topco Parent”), which vested based on either time (“time vesting awards”) or the achievement of certain performance and market conditions (“performance awards” and, together with the time vesting awards, the “pre-IPO awards”). In connection with the IPO, Topco Parent made in-kind distributions of restricted shares of our common stock to holders of pre-IPO awards as described in Note 15, “Stockholders' Equity”. The restricted shares of our common stock distributed in respect of pre-IPO time vesting awards vest through June 2025; expense related to these unvested awards will be recognized over the remaining vesting period. Expense attributable to the performance awards was recognized in its entirety in the year ended December 31, 2020 as the related performance conditions were considered probable of achievement and the implied service condition was met. Share-based compensation expense is recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss), primarily within “Selling, general and administrative expenses” at the grant date fair value over the requisite service period (one to four years for awards granted under the 2020 Plan and five years for time vesting pre-IPO awards on a straight-line basis). Fair value of the pre-IPO awards was estimated on the date of grant using a simulation-based option valuation model incorporating multiple and variable assumptions over time, including assumptions such as employee forfeitures, unit price volatility and dividend assumptions. We use the Black-Scholes option pricing model to measure the grant date fair value of stock options awarded under the 2020 Plan using certain valuation assumptions. Share-based compensation expense for all awards recognizes forfeitures as they occur.
Earnings (Loss) Per Share	Earnings (Loss) Per Share – In periods in which the Company has net income, earnings per share information is determined using the two-class method, which includes the weighted-average number of common shares outstanding during the period and securities that participate in dividends (“participating securities”). Our unvested restricted common stock distributed in respect of pre-IPO Class B-1 and B-2 awards have the right to receive non-forfeitable dividends or dividend equivalents if the Company declares dividends on its common stock. Under the two-class method, earnings are allocated to both common stock shares and participating securities based on their respective weighted-average shares outstanding for the period. Diluted earnings (loss) per common share incorporates the dilutive effect of common stock equivalents on an average basis during the period, if dilutive, in which case the dilutive effect of such securities is calculated using the more dilutive of (a) the two-class method, or (b) treasury stock method, as applicable, to the potentially dilutive instruments. Unvested restricted common stock is not included in the weighted average common shares outstanding figure within earnings per share until the period in which the vesting condition is satisfied. In periods in which the Company has a net loss, the two-class method is not applicable because the pre-IPO Class B-1 and B-2 restricted stock awards do not participate in losses. Refer to Note 17, “Earnings (Loss) Per Share” for additional information.
Treasury Stock	Treasury Stock – The Company records repurchases of its own common stock at cost. Repurchased common stock is presented as a reduction of equity in the Consolidated Balance Sheets. The difference between the repurchase and reissue price of the Company’s own stock is added to or deducted from additional paid-in capital. The cost of Treasury Stock reissued is calculated using a weighted average cost method.
Commitments and Contingencies	Commitments and Contingencies – Certain conditions may exist as of the date of the consolidated financial statements which may result in a loss to the Company but will only be resolved when one or more future events occur or fail to occur. Such liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties, settlement agreements, and other sources, are recorded when management assesses that it is probable that a future liability has been incurred and the amount can be reasonably estimated. Recoveries of costs from third parties, which management assesses as being probable of realization, are recorded to the extent related contingent liabilities are accrued. Legal costs incurred in connection with matters relating to contingencies are expensed in the period incurred. We record gain contingencies when realized.
Adoption of Accounting Standard Updates	Adoption of Accounting Standard Updates Effective January 1, 2023, we adopted Accounting Standards Update (“ASU”) ASU 2021-08-Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers (“ASU 2021-08”). The amendments in ASU 2021-08 require that an acquiring entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). At the acquisition date, an acquirer should account for the related revenue contracts in accordance with ASC Topic 606 as if it had originated the contracts. The adoption of this standard did not have a material impact on our consolidated financial statements and disclosures. ASUs Issued But Not Yet Adopted In November 2023, the Financial Accounting Standards Board (“FASB”) issued ASU 2023-07-Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. The amendments in ASU 2023-07 require an entity to provide enhanced disclosures about significant segment expenses. The amendments in this ASU are effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The Company is in the process of evaluating the impact of this standard on our consolidated financial statements and disclosures. In December 2023, the FASB issued ASU 2023-09-Income Taxes (Topic 740): Improvements to Income Tax Disclosures. The amendments in this ASU require entities to disclose, on an annual basis, specific categories in the reconciliation of the provision (benefit) for income taxes to the statutory rate and provide additional information for reconciling items that meet a quantitative threshold. Additionally, the update requires entities to disclose a disaggregation of taxes paid by category (federal, state and foreign taxes) as well as individual jurisdictions. For public business entities, the amendments in this ASU are effective for annual periods beginning after December 15, 2024. The Company is in the process of evaluating the impact of this standard on our consolidated financial statements and disclosures.

Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss)

Changes in our accumulated other comprehensive income (loss) balances, net of applicable tax, were as follows:


(thousands of U.S. dollars)	Defined Benefit Plans			Foreign Currency Translation		Interest Rate Derivatives			Total
Beginning balance – January 1, 2021	$	(44,143)		$	(49,699)	$	—		$	(93,842)
Other comprehensive income (loss) before reclassifications	25,517			(16,690)		404			9,231
Amounts reclassified from accumulated other comprehensive income (loss)	1,045		(a)	—		—		(b)	1,045
Net current-period other comprehensive income (loss)	26,562			(16,690)		404			10,276
Ending balance – December 31, 2021	$	(17,581)		$	(66,389)	$	404		$	(83,566)

Beginning balance – January 1, 2022	$	(17,581)		$	(66,389)	$	404		$	(83,566)
Other comprehensive income (loss) before reclassifications	20,803			(64,816)		20,939			(23,074)
Amounts reclassified from accumulated other comprehensive income (loss)	(13)		(a)	—		—			(13)
Net current-period other comprehensive income (loss)	20,790			(64,816)		20,939			(23,087)
Ending balance – December 31, 2022	$	3,209		$	(131,205)	$	21,343		$	(106,653)

Beginning balance – January 1, 2023	$	3,209		$	(131,205)	$	21,343		$	(106,653)
Other comprehensive income (loss) before reclassifications	(10,308)			40,174		6,441			36,307
Amounts reclassified from accumulated other comprehensive income (loss)	(198)		(a)	—		(22,138)			(22,336)
Net current-period other comprehensive income (loss)	(10,506)			40,174		(15,697)			13,971
Ending balance – December 31, 2023	$	(7,297)		$	(91,031)	$	5,646		$	(92,682)