Sotera Health (SHC) 10-Q 5 Aug 24 2024 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2024	Jul. 29, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		283,214,342
Entity Central Index Key	0001822479
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 246,084	$ 296,407
Restricted cash short-term	1,674	5,247
Accounts receivable, net of allowance for uncollectible accounts of $3,111 and $4,689, respectively	123,659	147,696
Inventories, net	57,872	48,316
Prepaid expenses and other current assets	56,652	53,846
Income taxes receivable	11,736	5,732
Total current assets	497,677	557,244
Property, plant, and equipment, net	994,614	946,914
Operating lease assets	24,272	24,037
Deferred income taxes	4,749	4,993
Post-retirement assets	30,721	28,482
Other assets	39,541	41,242
Other intangible assets, net	367,938	416,318
Goodwill	1,098,306	1,111,190
Total assets	3,057,818	3,130,420
Current liabilities:
Accounts payable	64,487	71,039
Accrued liabilities	69,054	122,471
Deferred revenues	12,989	13,492
Current portion of long-term debt	11,092	4,797
Current portion of finance lease obligations	2,767	8,771
Current portion of operating lease obligations	4,835	5,934
Income taxes payable	4,409	4,150
Total current liabilities	169,633	230,654
Long-term debt	2,213,518	2,223,674
Finance lease obligations, less current portion	93,518	63,793
Operating lease obligations, less current portion	21,353	20,087
Noncurrent asset retirement obligations	48,096	47,944
Deferred lease income	17,906	18,762
Post-retirement obligations	8,184	8,439
Noncurrent liabilities	8,762	8,879
Deferred income taxes	54,084	64,454
Total liabilities	2,635,054	2,686,686
See Commitments and contingencies note
Equity:
Common stock, with $0.01 par value, 1,200,000 shares authorized; 286,037 shares issued at June 30, 2024 and December 31, 2023	2,860	2,860
Preferred stock, with $0.01 par value, 120,000 authorized; no shares issued at June 30, 2024 and December 31, 2023	0	0
Treasury stock, at cost (2,823 and 3,207 shares at June 30, 2024 and December 31, 2023, respectively)	(24,764)	(27,182)
Additional paid-in capital	1,229,428	1,215,178
Retained deficit	(639,363)	(654,440)
Accumulated other comprehensive loss	(145,397)	(92,682)
Total equity	422,764	443,734
Total liabilities and equity	$ 3,057,818	$ 3,130,420

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Allowance for uncollectible accounts	$ 3,111	$ 4,689
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)	2,823,000	3,207,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues:
Total net revenues	$ 276,594	$ 255,282	$ 524,770	$ 475,872
Cost of revenues:
Total cost of revenues	123,803	115,694	244,864	224,781
Gross profit	152,791	139,588	279,906	251,091
Operating expenses:
Selling, general and administrative expenses	60,575	60,287	118,784	122,197
Amortization of intangible assets	15,417	16,097	31,149	32,324
Total operating expenses	75,992	76,384	149,933	154,521
Operating income	76,799	63,204	129,973	96,570
Interest expense, net	40,388	30,728	82,159	59,598
Loss on refinancing of debt	23,400	0	24,090	0
Foreign exchange (gain) loss	(611)	465	(1,183)	812
Other income, net	(1,520)	(2,474)	(1,249)	(3,727)
Income before income taxes	15,142	34,485	26,156	39,887
Provision for income taxes	6,388	10,972	11,079	13,532
Net income	8,754	23,513	15,077	26,355
Other comprehensive income (loss) net of tax:
Pension and post-retirement benefits (net of taxes of $10, $6, $47, and $(11), respectively)	30	18	143	(33)
Interest rate derivatives (net of taxes of $(857), $1,036, $(711) and $(2,360), respectively)	(2,461)	4,002	(2,042)	(5,249)
Foreign currency translation	(23,110)	21,374	(50,816)	32,631
Comprehensive income (loss)	$ (16,787)	$ 48,907	$ (37,638)	$ 53,704
Earnings per share:
Basic (in dollars per share)	$ 0.03	$ 0.08	$ 0.05	$ 0.09
Diluted (in dollars per share)	$ 0.03	$ 0.08	$ 0.05	$ 0.09
Weighted average number of shares outstanding:
Basic (in shares)	282,894	280,893	282,403	280,793
Diluted (in shares)	284,541	283,147	284,264	283,040
Service
Revenues:
Total net revenues	$ 237,756	$ 226,050	$ 464,237	$ 440,560
Cost of revenues:
Total cost of revenues	109,136	103,900	219,988	208,110
Product
Revenues:
Total net revenues	38,838	29,232	60,533	35,312
Cost of revenues:
Total cost of revenues	$ 14,667	$ 11,794	$ 24,876	$ 16,671

Consolidated Statements of Op_2

Consolidated Statements of Operations and Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Pension and post-retirement benefits, net of tax	$ 10	$ 6	$ 47	$ (11)
Interest rate derivatives, net of tax	$ (857)	$ 1,036	$ (711)	$ (2,360)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities:
Net income	$ 15,077	$ 26,355
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	40,381	37,920
Amortization of intangible assets	39,879	41,108
Loss on refinancing of debt	24,090	0
Deferred income taxes	(8,099)	315
Share-based compensation expense	18,844	15,661
Accretion of asset retirement obligations	1,278	1,127
Unrealized foreign exchange (gains) losses	(6,980)	4,601
Unrealized gain (loss) on derivatives not designated as hedging instruments	1,750	(747)
Amortization of debt issuance costs	4,704	4,112
Other	(3,258)	(2,623)
Changes in operating assets and liabilities:
Accounts receivable	22,261	2,549
Inventories	(11,084)	(3,877)
Other current assets	(3,602)	(9,220)
Accounts payable	(1,959)	(20,325)
Accrued liabilities	(18,585)	22,273
Income taxes payable / receivable, net	(5,343)	(14,067)
Other liabilities	(128)	(512)
Other long-term assets	(3,232)	358
Net cash provided by (used in) operating activities	70,994	(302,704)
Investing activities:
Purchases of property, plant and equipment	(76,811)	(98,134)
Other investing activities	37	32
Net cash used in investing activities	(76,774)	(98,102)
Financing activities:
Proceeds from long-term borrowings	2,259,350	500,000
Payment of revolving credit facility	0	(200,000)
Payments of debt issuance costs and debt discount	(30,204)	(24,672)
Payment on long-term borrowings	(2,260,600)	0
Buyout of leased facility	(6,736)	0
Other financing activities	(3,172)	(2,122)
Net cash (used in) provided by financing activities	(41,362)	273,206
Effect of exchange rate changes on cash and cash equivalents	(6,754)	1,796
Net decrease in cash and cash equivalents, including restricted cash	(53,896)	(125,804)
Cash and cash equivalents, including restricted cash, at beginning of period	301,654	396,294
Cash and cash equivalents, including restricted cash, at end of period	247,758	270,490
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	111,169	78,352
Cash paid during the period for income taxes, net of tax refunds received	27,714	27,590
Purchases of property, plant and equipment included in accounts payable	13,538	16,986
Ethylene Oxide Tort Litigation - Illinois
Changes in operating assets and liabilities:
Illinois EO litigation settlement	0	(407,712)
Ethylene Oxide Tort Litigation – Georgia
Changes in operating assets and liabilities:
Illinois EO litigation settlement	$ (35,000)	$ 0

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings / (Accumulated Deficit)	Accumulated Other Comprehensive (Loss) Income
Beginning balance (in shares) at Dec. 31, 2022		282,421
Beginning balance at Dec. 31, 2022	$ 350,238	$ 2,860	$ (29,775)	$ 1,189,622	$ (705,816)	$ (106,653)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation plans (in shares)		123
Share-based compensation plans	14,425		1,075	13,350
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	(33)					(33)
Foreign currency translation	32,631					32,631
Interest rate derivatives, net of tax	(5,249)					(5,249)
Net income	26,355				26,355
Ending balance (in shares) at Jun. 30, 2023		282,544
Ending balance at Jun. 30, 2023	418,367	$ 2,860	(28,700)	1,202,972	(679,461)	(79,304)
Beginning balance (in shares) at Mar. 31, 2023		282,516
Beginning balance at Mar. 31, 2023	361,125	$ 2,860	(29,420)	1,195,357	(702,974)	(104,698)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation plans (in shares)		28
Share-based compensation plans	8,335		720	7,615
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	18					18
Foreign currency translation	21,374					21,374
Interest rate derivatives, net of tax	4,002					4,002
Net income	23,513				23,513
Ending balance (in shares) at Jun. 30, 2023		282,544
Ending balance at Jun. 30, 2023	418,367	$ 2,860	(28,700)	1,202,972	(679,461)	(79,304)
Ending balance (in shares) at Jun. 30, 2024		283,214
Ending balance at Jun. 30, 2024	422,764	$ 2,860	(24,764)	1,229,428	(639,363)	(145,397)
Beginning balance (in shares) at Dec. 31, 2023		282,830
Beginning balance at Dec. 31, 2023	443,734	$ 2,860	(27,182)	1,215,178	(654,440)	(92,682)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation plans (in shares)		384
Share-based compensation plans	16,668		2,418	14,250
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	143					143
Foreign currency translation	(50,816)					(50,816)
Interest rate derivatives, net of tax	(2,042)					(2,042)
Net income	15,077				15,077
Ending balance (in shares) at Jun. 30, 2024		283,214
Ending balance at Jun. 30, 2024	422,764	$ 2,860	(24,764)	1,229,428	(639,363)	(145,397)
Beginning balance (in shares) at Mar. 31, 2024		283,071
Beginning balance at Mar. 31, 2024	429,392	$ 2,860	(26,042)	1,220,547	(648,117)	(119,856)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation plans (in shares)		143
Share-based compensation plans	10,159		1,278	8,881
Comprehensive income (loss):
Pension and post-retirement plan adjustments, net of tax	30					30
Foreign currency translation	(23,110)					(23,110)
Interest rate derivatives, net of tax	(2,461)					(2,461)
Net income	8,754				8,754
Ending balance (in shares) at Jun. 30, 2024		283,214
Ending balance at Jun. 30, 2024	$ 422,764	$ 2,860	$ (24,764)	$ 1,229,428	$ (639,363)	$ (145,397)

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation 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. We operate and report in three segments, Sterigenics, Nordion and Nelson Labs. We describe our reportable segments in Note 16, “Segment Information”. All intercompany balances and transactions have been eliminated in consolidation. 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. Interim Financial Statements – The accompanying consolidated financial statements include the assets, liabilities, operating results, and cash flows of the Company and its wholly owned subsidiaries. These financial statements are prepared in accordance with GAAP for interim financial information, the instructions to the Quarterly Report on Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. These unaudited interim financial statements should be read in conjunction with the Company's annual consolidated financial statements and accompanying notes in our 2023 10-K.

Recent Accounting Standards

Recent Accounting Standards	6 Months Ended
	Jun. 30, 2024
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standards	Recent Accounting Standards Accounting Standard Updates (“ASU”) 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.

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition The following table shows disaggregated net revenues from contracts with external customers by timing of revenue and by segment for the three and six months ended June 30, 2024 and 2023: (thousands of U.S. dollars) Three Months Ended June 30, 2024 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 176,354 $ 40,974 $ — $ 217,328 Over time — 270 58,996 59,266 Total $ 176,354 $ 41,244 $ 58,996 $ 276,594 (thousands of U.S. dollars) Three Months Ended June 30, 2023 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 166,590 $ 30,653 $ — $ 197,243 Over time — 1,322 56,717 58,039 Total $ 166,590 $ 31,975 $ 56,717 $ 255,282 (thousands of U.S. dollars) Six Months Ended June 30, 2024 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 342,851 $ 64,025 $ — $ 406,876 Over time — 1,226 116,668 117,894 Total $ 342,851 $ 65,251 $ 116,668 $ 524,770 (thousands of U.S. dollars) Six Months Ended June 30, 2023 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 326,587 $ 38,241 $ — $ 364,828 Over time — 2,285 108,759 111,044 Total $ 326,587 $ 40,526 $ 108,759 $ 475,872 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 $13.0 million and $13.5 million at June 30, 2024 and December 31, 2023, 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.

Inventories

Inventories	6 Months Ended
	Jun. 30, 2024
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories consisted of the following: (thousands of U.S. dollars) June 30, 2024 December 31, 2023 Raw materials and supplies $ 46,626 $ 43,411 Work-in-process 2,371 471 Finished goods 9,104 4,670 58,101 48,552 Reserve for excess and obsolete inventory (229) (236) Inventories, net $ 57,872 $ 48,316

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	6 Months Ended
	Jun. 30, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following: (thousands of U.S. dollars) June 30, 2024 December 31, 2023 Prepaid taxes $ 3,709 $ 4,129 Prepaid business insurance 3,827 7,174 Prepaid rent 1,226 1,150 Customer contract assets 21,599 17,785 Current deposits 501 715 Prepaid maintenance contracts 455 422 Value added tax receivable 3,576 4,306 Prepaid software licensing 2,746 2,503 Stock supplies 3,881 3,669 Embedded derivatives 1,571 1,225 Other 13,561 10,768 Prepaid expenses and other current assets $ 56,652 $ 53,846

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Changes to goodwill during the six months ended June 30, 2024 were as follows: (thousands of U.S. dollars) Sterigenics Nordion Nelson Labs Total Goodwill at December 31, 2023 $ 659,888 $ 276,929 $ 174,373 $ 1,111,190 Changes due to foreign currency exchange rates (3,311) (8,582) (991) (12,884) Goodwill at June 30, 2024 $ 656,577 $ 268,347 $ 173,382 $ 1,098,306 Other intangible assets consisted of the following: (thousands of U.S. dollars) Gross Carrying Amount Accumulated Amortization As of June 30, 2024 Finite-lived intangible assets Customer relationships $ 652,688 $ 511,941 Proprietary technology 75,453 51,222 Trade names 2,545 1,425 Land-use rights 8,529 1,912 Sealed source and supply agreements 202,400 110,243 Other 4,448 3,302 Total finite-lived intangible assets 946,063 680,045 Indefinite-lived intangible assets Regulatory licenses and other (a) 76,229 — Trade names / trademarks 25,691 — Total indefinite-lived intangible assets 101,920 — Total $ 1,047,983 $ 680,045 As of December 31, 2023 Gross Carrying Amount Accumulated Amortization 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 (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 $19.8 million and $20.5 million for the three months ended June 30, 2024 and 2023, respectively. $15.4 million and $16.1 million was included in “Amortization of intangible assets” in the Consolidated Statements of Operations and Comprehensive Income (Loss) for the three months ended June 30, 2024 and 2023, respectively, whereas the remainder was included in “Cost of revenues.” Amortization expense for finite-lived intangible assets was $39.9 million and $41.1 million for the six months ended June 30, 2024 and 2023, respectively. $31.1 million and $32.3 million was included in “Amortization of intangible assets” in the Consolidated Statements of Operations and Comprehensive Income (Loss) for the three and six months ended June 30, 2023, respectively. 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) For the remainder of 2024 $ 39,468 2025 42,138 2026 22,039 2027 20,962 2028 20,414 Thereafter 120,997 Total $ 266,018 The weighted-average remaining useful life of the finite-lived intangible assets was approximately nine years as of June 30, 2024.

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consisted of the following: (thousands of U.S. dollars) June 30, 2024 December 31, 2023 Accrued employee compensation $ 30,352 $ 35,037 Georgia EO litigation settlement reserve — 35,000 Illinois EO litigation settlement reserve — 288 Other legal reserves 370 1,480 Accrued interest expense 6,422 26,681 Embedded derivatives 2,508 414 Professional fees 17,367 12,691 Accrued utilities 1,924 2,056 Insurance accrual 3,248 2,922 Accrued taxes 2,337 2,407 Other 4,526 3,495 Accrued liabilities $ 69,054 $ 122,471

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2024
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consisted of the following: (thousands of U.S. dollars) As of June 30, 2024 Gross Amount Unamortized Debt Issuance Costs Unamortized Debt Discount Net Amount Secured notes due 2031 $ 750,000 $ (3,996) $ — 746,004 Term loan due 2031 1,509,350 (7,002) (23,742) 1,478,606 2,259,350 (10,998) (23,742) 2,224,610 Less current portion 11,320 (51) (177) 11,092 Long-term debt $ 2,248,030 $ (10,947) $ (23,565) $ 2,213,518 (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 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 “Credit Agreement”). 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. On May 30, 2024, the Company and SHH entered into Amendment No. 4 (“Amendment No. 4”) to the Senior Secured Credit Facilities. Among other changes, Amendment No. 4 provides for term loans (the “Refinancing Term Loans”) to SHH in an aggregate principal amount of $1,509.4 million. Pursuant to Amendment No. 4, the Refinancing Term Loans shall have an applicable interest rate margin per annum equal to (i) ABR plus 2.25% for ABR Loans (as defined in the Credit Agreement), (ii) daily simple SOFR plus 3.25% for RFR Loans (as defined in the Credit Agreement) and (iii) Term SOFR plus 3.25% for Term Benchmark Loans (as defined in the Credit Agreement), in each case with a 0.00% applicable floor and the applicable interest rate margin shall be subject to a pricing step-down of 0.25% when the Senior Secured Leverage Ratio (as defined in the Credit Agreement) is less than or equal to 3.30:1.00. The Refinancing Term Loans are also subject to a “soft call” premium of 1.00% for certain repricing transactions with respect to the Refinancing Term Loans that occur within the six-month period after the effective date of Amendment No. 4. The Refinancing Term Loans amortize at a rate of 1.00% per annum and mature on May 30, 2031. The weighted average interest rate on borrowings under the Refinancing Term Loans for the three months ended June 30, 2024 was 8.58%. On May 30, 2024, SHH, the Company and certain subsidiaries of the Company (the “Guarantors”), and Wilmington Trust, National Association, as trustee, paying agent, registrar, transfer agent and notes collateral agent, entered into an indenture (the “Indenture”) governing SHH’s newly issued $750.0 million aggregate principal amount of 7.375% senior secured notes due 2031 (the “Secured Notes”). The Secured Notes will pay interest semiannually in arrears on June 1 and December 1 of each year, beginning on December 1, 2024, at a rate of 7.375% per year, and will mature on June 1, 2031. The Secured Notes may be redeemed, at any time or from time to time, in whole or in part, on or after June 1, 2027 at the redemption prices specified in the Indenture, together with accrued and unpaid interest, if any, thereon to, but excluding, the redemption date. At any time or from time to time, prior to June 1, 2027, the Secured Notes may be redeemed, in whole or in part, at a redemption price equal to 100% of the aggregate principal amount thereof plus a make-whole premium, together with accrued and unpaid interest, if any, thereon to, but excluding, the redemption date. In addition, at any time or from time to time, prior to June 1, 2027, SHH may redeem up to 40% of the aggregate principal amount of the Secured Notes (including any additional Secured Notes issued under the Indenture) with an amount not to exceed the net cash proceeds from certain equity offerings at a redemption price equal to 107.375% of the aggregate principal amount thereof plus accrued and unpaid interest, if any, thereon to, but excluding, the redemption date. Further, at any time or from time to time, on or before June 1, 2027, SHH may redeem up to 10% of the then outstanding aggregate principal amount of Secured Notes (including any additional Secured Notes issued under the Indenture) during each of the twelve-month periods after the issue date, at a redemption price equal to 103% of the aggregate principal amount thereof, plus accrued and unpaid interest, if any, thereon to, but excluding, the redemption date. The obligations under the Indenture are secured pursuant to a security agreement, dated as of May 30, 2024, by and among SHH, the Company, the other grantors party thereto, and Wilmington Trust, National Association (the “Security Agreement”), as may be amended from time to time, and related financing statements. The Company used the combined net proceeds from the Refinancing Terms Loans and Secured Notes, along with cash on hand, to refinance its existing $1,763.1 million Term Loan due 2026 and $496.3 million Term Loan B due 2026. On March 1, 2024, the Company and SHH entered into Amendment No. 3 (“Amendment No. 3”) to the Revolving Credit Facility. Among other changes, Amendment No. 3 provides (i) for new commitments under the existing Revolving Credit Facility to replace the existing revolving commitments in an aggregate principal amount of $83.0 million, (ii) that certain of the lenders providing revolving credit commitments shall also provide additional commitments for the issuance of letters of credit under the Revolving Credit Facility in an aggregate principal amount of $37.5 million and (iii) for the extension of the maturity date of the Revolving Credit Facility to March 1, 2029. The Senior Secured Credit Facilities and the Indenture contain additional covenants that, among other things, restrict, subject to certain exceptions, limitations and qualifications, our ability and the ability of our restricted subsidiaries to engage in certain activities, such as incur additional 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 the Indenture. The Senior Secured Credit Facilities and the Indenture also contain certain customary affirmative covenants and events of default, including upon a change of control. In addition, an event of default under the Senior Secured Credit Facilities and the Indenture would occur if the Company or certain of its subsidiaries received one or more enforceable judgments for payment in an aggregate amount in excess of the greater of (i) $162.6 million or (ii) 30.0% of consolidated EBITDA or LTM EBITDA (as defined in the Credit Agreement and the Indenture, respectively) and the judgments were not stayed or remained undischarged for a period of 60 consecutive days. As of June 30, 2024, we were in compliance with all of the covenants under the Senior Secured Credit Facilities and the Indenture. All of SHH’s obligations under the Senior Secured Credit Facilities and the Indenture 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 the Indenture, 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, the Indenture and the Security 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 June 30, 2024, 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 SOFR. For additional information on the derivative instruments described above, refer to Note 15, “Financial Instruments and Financial Risk”, “Derivative Instruments.” Aggregate Maturities Aggregate maturities of the Company’s long-term debt, excluding debt discounts, as of June 30, 2024, are as follows: (thousands of U.S. dollars) 2024 $ 3,773 2025 15,094 2026 15,094 2027 15,094 2028 15,094 Thereafter 2,195,201 Total $ 2,259,350

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense is provided on an interim basis based upon our estimate of the annual effective income tax rate. In determining the estimated annual effective income tax rate, we analyze various factors, including projections of our annual earnings and the taxing jurisdictions where the earnings will occur, the impact of state and local taxes, our ability to utilize tax credits and net operating loss carryforwards and available tax planning alternatives. Our effective tax rates were 42.2% and 42.4% for the three and six months ended June 30, 2024, respectively, compared to 31.8% and 33.9% for the three and six months ended June 30, 2023, respectively. Income tax expense for the three and six months ended June 30, 2024 differed from the statutory rate primarily due to t he valuation allowance attributable to the limitation on the deductibility of interest expense and the impact of the foreign rate differential, partially offset by a benefit for state income taxes. Income tax expense for the three and six months ended June 30, 2023 differed from the statutory rate primarily due to a net increase in the valuation allowance attributable to the limitation on the deductibility of interest expense, the impact of the foreign rate differential, and global intangible low-tax income (“GILTI”). Income tax expense for the six months ended June 30, 2023 was also favorably impacted by a benefit for state income taxes.

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 30, 2024
Postemployment Benefits [Abstract]
Employee Benefits	Employee Benefits The Company sponsors various post-employment benefit plans including, in certain countries outside the U.S., defined benefit and defined contribution pension 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. Certain immaterial foreign defined benefit pension plans have been excluded from the table below. The interest cost, expected return on plan assets and amortization of net actuarial gain 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 pension benefit for the defined benefit plan for the three and six months ended June 30, 2024 and 2023 were as follows: Three Months Ended June 30, Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 2024 2023 Service cost $ 142 $ 132 $ 287 $ 263 Interest cost 2,612 2,742 5,263 5,466 Expected return on plan assets (3,961) (4,046) (7,980) (8,065) Net periodic benefit $ (1,207) $ (1,172) $ (2,430) $ (2,336) 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. Certain immaterial other foreign benefit plans have been excluded from the table below. All but one non-pension post-employment benefit plans are unfunded. The components of net periodic benefit cost for the other benefit plans for the three and six months ended June 30, 2024 and 2023 were as follows: Three Months Ended June 30, Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 2024 2023 Service cost $ 2 $ 2 $ 5 $ 4 Interest cost 85 90 171 180 Amortization of net actuarial gain (33) (44) (66) (88) Net periodic benefit cost $ 54 $ 48 $ 110 $ 96 The Company currently has no funding requirements as the Nordion pension plan has a going concern surplus as defined by Canadian federal regulation, which requires solvency testing on defined benefit pension plans on an annual basis.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2024
Equity [Abstract]
Other Comprehensive Income (Loss)	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 – April 1, 2024 $ (7,184) $ (118,737) $ 6,065 $ (119,856) Other comprehensive income (loss) before reclassifications 63 (23,110) 1,177 (21,870) Amounts reclassified from accumulated other comprehensive income (loss) (33) (a) — (3,638) (b) (3,671) Net current-period other comprehensive income (loss) 30 (23,110) (2,461) (25,541) Ending balance – June 30, 2024 $ (7,154) $ (141,847) $ 3,604 $ (145,397) Beginning balance – January 1, 2024 $ (7,297) $ (91,031) $ 5,646 (92,682) Other comprehensive income (loss) before reclassifications 209 (50,816) 5,228 (45,379) Amounts reclassified from accumulated other comprehensive income (loss) (66) (a) — (7,270) (b) (7,336) Net current-period other comprehensive income (loss) 143 (50,816) (2,042) (52,715) Ending balance – June 30, 2024 $ (7,154) $ (141,847) $ 3,604 $ (145,397) (thousands of U.S. dollars) Defined Benefit Plans Foreign Currency Translation Interest Rate Derivatives Total Beginning balance – April 1, 2023 $ 3,158 $ (119,948) $ 12,092 $ (104,698) Other comprehensive income (loss) before reclassifications 62 21,374 10,950 32,386 Amounts reclassified from accumulated other comprehensive income (loss) (44) (a) — (6,948) (6,992) Net current-period other comprehensive income (loss) 18 21,374 4,002 25,394 Ending balance – June 30, 2023 $ 3,176 $ (98,574) $ 16,094 $ (79,304) Beginning balance – January 1, 2023 $ 3,209 $ (131,205) $ 21,343 $ (106,653) Other comprehensive income (loss) before reclassifications 55 32,631 8,555 41,241 Amounts reclassified from accumulated other comprehensive income (loss) (88) (a) — (13,804) (13,892) Net current-period other comprehensive income (loss) (33) 32,631 (5,249) 27,349 Ending balance – June 30, 2023 $ 3,176 $ (98,574) $ 16,094 $ (79,304) (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).

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Share-Based Compensation	Share-Based Compensation Pre-IPO Awards 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 were considered performance vesting units. The required performance threshold for the vesting of B-2 restricted stock is 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. Both performance thresholds were satisfied on March 4, 2024 and, as a result, all outstanding B-2 Units fully vested as of that date. 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. We recognized $0.4 million and $0.5 million of share-based compensation expense related to the pre-IPO Class B-1 awards for the three months ended June 30, 2024 and 2023, respectively, and $0.8 million and $1.0 million for the six months ended June 30, 2024 and 2023, respectively. A summary of the activity for the six months ended June 30, 2024 related to the restricted stock awards distributed in respect of the pre-IPO awards (Class B-1 and B-2 Units) is presented below: Restricted Stock - Pre- IPO B-1 Restricted Stock - Pre- IPO B-2 Unvested at December 31, 2023 352,447 987,111 Forfeited (2,650) — Vested (144,795) (987,111) Unvested at June 30, 2024 205,002 — 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. We recognized $9.8 million ($4.6 million for stock options and $5.2 million for RSUs) and $7.9 million ($3.7 million for stock options and $4.2 million for RSUs) of share-based compensation expense for these awards for the three months ended June 30, 2024 and 2023, respectively. We recognized $18.1 million ($8.6 million for stock options and $9.5 million for RSUs) and $14.7 million ($6.8 million for stock options and $7.9 million for RSUs) for the six months ended June 30, 2024 and 2023, respectively, in our Consolidated Statements of Operations and Comprehensive Income (Loss), in “Selling, general and administrative expenses.” Stock Options Stock options generally vest ratably over a period of two Number of Shares Weighted-average Exercise Price At December 31, 2023 6,972,661 $ 15.17 Granted 1,586,669 14.56 Forfeited (80,751) 19.45 At June 30, 2024 8,478,579 $ 15.02 As of June 30, 2024, there were 4.2 million vested and exercisable stock options. RSUs RSUs generally vest ratably over a period of one Number of Shares Weighted-average Grant Date Fair Value Unvested at December 31, 2023 2,298,836 $ 13.81 Granted 1,181,863 13.98 Forfeited (48,125) 15.05 Vested (538,939) 17.55 Unvested at June 30, 2024 2,893,635 $ 13.16

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic earnings per share represents the amount of income attributable to each common share outstanding. Diluted earnings per share represents the amount of income 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 were to declare 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. As of March 4, 2024, the performance threshold applicable to all Class B-2 restricted stock awards were fully satisfied, thereby releasing the vesting and forfeiture restrictions on these common shares. Beginning on that date, B-2 restricted stock was not included in the earnings allocation. 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. Our basic and diluted earnings per common share are calculated as follows: Three Months Ended Six Months Ended in thousands of U.S. dollars and share amounts (except per share amounts) June 30, June 30, June 30, June 30, Earnings: Net income $ 8,754 $ 23,513 $ 15,077 $ 26,355 Less: Allocation to participating securities 7 137 33 159 Net income attributable to Sotera Health Company common shareholders $ 8,747 $ 23,376 $ 15,044 $ 26,196 Weighted Average Common Shares: Weighted-average common shares outstanding - basic 282,894 280,893 282,403 280,793 Dilutive effect of potential common shares 1,647 2,254 1,861 2,247 Weighted-average common shares outstanding - diluted 284,541 283,147 284,264 283,040 Earnings per Common Share: Net income per common share attributable to Sotera Health Company common shareholders - basic $ 0.03 $ 0.08 $ 0.05 $ 0.09 Net income per common share attributable to Sotera Health Company common shareholders - diluted 0.03 0.08 0.05 0.09 Diluted earnings per share does not consider the following potential common shares as the effect would be anti-dilutive: Three Months Ended Six Months Ended in thousands of share amounts June 30, June 30, June 30, June 30, Stock options 5,776 4,283 5,248 3,928 RSUs 1,800 1,308 1,583 1,138 Total anti-dilutive securities 7,576 5,591 6,831 5,066

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies 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 approximately 40 lawsuits in Illinois in which plaintiffs allege personal injuries or wrongful death resulting from purported emissions and releases of EO from Sterigenics’ former Willowbrook facility (the “Willowbrook Cases”). The Willowbrook Cases are pending in the Circuit Court of Cook County and have been assigned to a single judge for coordinated discovery and pretrial proceedings. We intend to vigorously defend the Willowbrook Cases. Georgia Subsidiaries of the Company 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 (the “Atlanta Cases”). Approximately 280 personal injury and wrongful death claims are 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 while working at the customer’s distribution facility by exposure 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. Subsidiaries of the Company are also defendants in approximately 365 property devaluation lawsuits pending in the State Court of Cobb County that have been consolidated for pretrial purposes (the “Consolidated Property Cases”). Nine of the Consolidated Property Cases are proceeding under case management orders and the remaining cases are stayed. We intend to vigorously defend the Atlanta Cases. California Subsidiaries of the Company and other parties are defendants in two lawsuits in Los Angeles County Superior Court in which plaintiffs allege personal injuries and wrongful death resulting from emissions and releases of EO from Sterigenics’ Vernon facilities (the “Vernon Cases”). The lawsuits remain in preliminary stages. We intend to vigorously defend the Vernon 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 have deteriorated the air quality in surrounding communities and materially contributed to increased health risks for residents of those communities. In April 2024, the Court of Appeals of the State of New Mexico denied the NMAG’s petition for leave to file an interlocutory appeal of the August 2023 order granting Sterigenics’ motion for summary judgment on strict liability, the Unfair Practices Act claim, and the claims for decreased property values, increased healthcare costs and medical monitoring costs. The case has been remanded to the District Court of Doña Ana County for further proceedings on the remaining claims. The case is set for trial in July 2026. A defense motion challenging the Court’s jurisdiction over Sotera Health Company and another defendant 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 while the decedent was working at a different company’s facility approximately one mile away. The case is set for trial in October 2025. We intend to vigorously defend the lawsuits relating to the Santa Teresa facility. * * * Additional EO tort lawsuits may be filed in the future against the Company and/or its subsidiaries relating to Sterigenics’ Willowbrook, Atlanta, Santa Teresa, Vernon 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 (as previously defined in Note 20, Commitments and Contingencies of our 2023 10-K) 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, California 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 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. The Delaware Superior Court case is stayed pending resolution of the coverage lawsuit in the Circuit Court of Cook County, Illinois. 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. The Company has also received demands pursuant to 8 Del. C. §220 for inspections of its books and records (“220 Demands”) from shareholders purporting to investigate potential wrongdoing by Company fiduciaries and other issues. The Company has produced documents in response to the 220 Demands and may produce additional documents. In May 2024, a stockholder derivative lawsuit was filed in the Court of Chancery of the State of Delaware for the benefit of the Company as the nominal defendant (“the May 2024 Derivative Litigation”). The May 2024 Derivative Litigation plaintiffs allege breaches of fiduciary duties, insider trading, unjust enrichment and other violations by certain past and present directors and senior executives of the Company and the Company’s private equity stockholders. On June 25, 2024, the court stayed the May 2024 Derivative Litigation pending a ruling on the merits on the motion to dismiss the Amended Complaint in the Michigan Funds Litigation. The Company believes that the allegations and claims in the Michigan Funds Litigation, 220 Demands and May 2024 Derivative Litigation are without merit, and plans to vigorously defend the Michigan Funds Litigation and May 2024 Derivative Litigation .

Financial Instruments and Finan

Financial Instruments and Financial Risk	6 Months Ended
	Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Instruments and Financial Risk	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 variable rate borrowings. 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 became effective as of July 31, 2023 and expired on July 31, 2024. We 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 variable rate borrowings. Accordingly, the interest rate cap agreements hedged 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 were designated as cash flow hedges 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 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 expense (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: June 30, 2024 December 31, 2023 (in U.S. Dollars; notional in millions, fair value in thousands) Fair Value Fair Value Notional Derivative Derivative Notional Derivative Derivative Derivatives designated as hedging instruments Interest rate caps $ 1,000.0 $ 1,528 — $ 1,000.0 $ 8,763 $ — Interest rate swaps 400.0 3,817 — 400.0 1,487 — Derivatives not designated as hedging instruments Foreign currency forward contracts $ 204.4 $ 84 $ 17 $ 171.0 $ 149 $ 9 Embedded derivatives 136.7 (a) 1,571 2,508 150.1 1,225 405 Total $ 1,741.1 $ 7,000 $ 2,525 $ 1,721.1 $ 11,624 $ 414 (a) Represents the total notional amounts for certain of the Company’s supply and sales contracts accounted for as embedded derivatives. Embedded derivative assets/liabilities 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 table summarizes the activities of our derivative instruments for the periods presented, and the line item in which they are recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss): (thousands of U.S. dollars) Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Realized gain on interest rate derivatives recorded in interest expense, net (a) (4,906) (9,400) (9,802) (18,571) Unrealized loss (gain) on embedded derivatives recorded in other expense (income), net (83) (973) 1,750 (747) Realized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss 1,499 (2,393) 5,507 (1,944) Unrealized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss 653 — 73 (282) (a) Amounts primarily represent quarterly settlement of interest rate caps and swaps. We expect to reclassify approximately $4.8 million of pre-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 11, “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 three and six months ended June 30, 2024. 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 June 30, 2024 and December 31, 2023, accounts receivable was net of an allowance for uncollectible accounts of $3.1 million and $4.7 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 of our financial assets and liabilities: As of June 30, 2024 Fair Value (thousands of U.S. dollars) Carrying Level 1 Level 2 Level 3 Derivatives designated as hedging instruments (a) Interest rate caps $ 1,528 $ — $ 1,528 $ — Interest rate swaps 3,817 — 3,817 — Derivatives not designated as hedging instruments (b) Foreign currency forward contract assets 84 — 84 — Foreign currency forward contract liabilities 17 — 17 — Embedded derivative assets 1,571 — 1,571 — Embedded derivative liabilities 2,508 — 2,508 — Current portion of long-term debt (c) Term loan, due 2031 11,092 — 11,292 — Long-Term Debt (c) Senior secured notes, due 2031 746,004 — 749,100 — Term loan, due 2031 1,467,514 — 1,494,285 — Finance Lease Obligations (with current portion) (d) 96,285 — 96,285 — As of December 31, 2023 Fair Value (thousands of U.S. dollars) Carrying 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 contracts 149 — 149 — Foreign currency forward 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 — (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 and yield curves. (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). 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 the foreign currency exchange rate over the life of the contract. (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 are based upon quoted prices for each Term Loan and the Secured Notes in inactive markets as provided by an independent fixed income security pricing service. (d) Fair value approximates carrying value.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2024
Segment Reporting [Abstract]
Segment Information	Segment 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” of the Company’s annual consolidated financial statements and accompanying notes in our 2023 10-K. 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. For the three months ended June 30, 2024, three customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 20.6%, 17.0% and 10.5% of the total segment’s external net revenues for the three months ended June 30, 2024. For the three months ended June 30, 2023, five customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 31.3%, 13.4%, 12.5%, 10.7% and 10.7% of the total segment’s external net revenues for the three months ended June 30, 2023. For the six months ended June 30, 2024, four customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 20.0%, 12.8%, 12.4% and 10.0% of the total segment’s external net revenues for the six months ended June 30, 2024. For the six months ended June 30, 2023, four customers reported within the Nordion segment individually represented 10% or more of the segment’s total net revenues. These customers represented 26.3%, 17.5%, 10.7% and 10.1% of the total segment's external net revenues for the six months ended June 30, 2023. Financial information for each of our segments is presented in the following table: Three Months Ended June 30, Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 2024 2023 Segment revenues (a) Sterigenics $ 176,354 $ 166,590 $ 342,851 $ 326,587 Nordion 41,244 31,975 65,251 40,526 Nelson Labs 58,996 56,717 116,668 108,759 Total net revenues $ 276,594 $ 255,282 $ 524,770 $ 475,872 Segment income (b) Sterigenics $ 96,778 $ 91,450 $ 182,596 $ 174,290 Nordion 23,420 17,784 34,205 19,310 Nelson Labs 17,137 19,251 32,478 33,353 Total segment income $ 137,335 $ 128,485 $ 249,279 $ 226,953 (a) Revenues are reported net of intersegment sales. Our Nordion segment recognized $17.9 million and $14.7 million in revenues from sales to our Sterigenics segment for the three months ended June 30, 2024 and 2023, respectively, and $27.9 million and $17.6 million in revenues from sales to our Sterigenics segment for the six months ended June 30, 2024 and 2023, respectively, that is not reflected in net revenues in the table above. Intersegment sales for Sterigenics and Nelson Labs are immaterial for these periods. (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 six months ended June 30, 2024 and 2023 were as follows: Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 Sterigenics $ 53,798 $ 73,725 Nordion 19,463 16,283 Nelson Labs 3,550 8,126 Total capital expenditures $ 76,811 $ 98,134 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 before taxes is as follows: (thousands of U.S. dollars) Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Segment income $ 137,335 $ 128,485 $ 249,279 $ 226,953 Less adjustments: Interest expense, net (a) 40,388 30,728 82,159 59,598 Depreciation and amortization (b) 39,830 39,490 80,260 79,028 Share-based compensation (c) 10,206 8,409 18,863 15,757 Loss on refinancing of debt (d) 23,400 — 24,090 — (Gain) loss on foreign currency and derivatives not designated as hedging instruments, net (e) (698) (409) 532 126 Business optimization expenses (f) 593 3,604 647 5,835 Professional services relating to EO sterilization facilities (g) 7,818 11,623 14,157 25,595 Secondary offering costs (h) 20 — 1,137 — Accretion of asset retirement obligation (i) 636 555 1,278 1,127 Consolidated income before taxes $ 15,142 $ 34,485 $ 26,156 $ 39,887 (a) Interest expense, net presented in this reconciliation for the three and six months ended June 30, 2023 has been adjusted to conform to the current year presentation to include interest expense, net on Term Loan B due 2026 attributable to the loan proceeds that were used to fund the $408.0 million Illinois EO litigation settlement. (b) Includes depreciation of Co-60 held at gamma irradiation sites. (c) Represents share-based compensation expense to employees and Non-Employee Directors. (d) Represents the write-off of unamortized debt issuance costs and discounts, as well as certain other costs incurred related to the Refinancing Term Loans and the Secured Notes. The six months ended June 30, 2024 includes $0.7 million of debt refinancing costs related to Amendment No. 3 to the Senior Secured Credit Facilities. (e) Represents the effects of (i) fluctuations in foreign currency exchange rates and (ii) non-cash mark-to-fair value of embedded derivatives relating to certain customer and supply contracts at Nordion. (f) Represents (i) certain costs related to acquisitions and the integration of recent 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) professional fees and other costs associated with business optimization, cost saving and other process enhancement projects, and (v) professional fees, payroll costs, and other costs, including ongoing lease and utility expenses associated with the closure of the Willowbrook, Illinois facility. The six months ended June 30, 2023 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. (g) Represents litigation and other professional fees associated with our EO sterilization facilities. Amounts presented for the three and six months ended June 30, 2023 have been adjusted to exclude interest expense, net associated with Term Loan B due 2026 attributable to the loan proceeds that were used to fund the $408.0 million Illinois EO litigation settlement. (h) Represents expenses incurred in connection with the secondary offering of our common stock that closed on March 4, 2024. (i) Represents non-cash accretion of asset retirement obligations related to Co-60 and gamma 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.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net income	$ 8,754	$ 23,513	$ 15,077	$ 26,355

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2024
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

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation
Use of Estimates	Use of Estimates
Interim Financial Statements	Interim Financial Statements – The accompanying consolidated financial statements include the assets, liabilities, operating results, and cash flows of the Company and its wholly owned subsidiaries. These financial statements are prepared in accordance with GAAP for interim financial information, the instructions to the Quarterly Report on Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. These unaudited interim financial statements should be read in conjunction with the Company's annual consolidated financial statements and accompanying notes in our 2023 10-K.
Adoption of Accounting Standard Updates	Accounting Standard Updates (“ASU”) 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.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2024
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 three and six months ended June 30, 2024 and 2023: (thousands of U.S. dollars) Three Months Ended June 30, 2024 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 176,354 $ 40,974 $ — $ 217,328 Over time — 270 58,996 59,266 Total $ 176,354 $ 41,244 $ 58,996 $ 276,594 (thousands of U.S. dollars) Three Months Ended June 30, 2023 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 166,590 $ 30,653 $ — $ 197,243 Over time — 1,322 56,717 58,039 Total $ 166,590 $ 31,975 $ 56,717 $ 255,282 (thousands of U.S. dollars) Six Months Ended June 30, 2024 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 342,851 $ 64,025 $ — $ 406,876 Over time — 1,226 116,668 117,894 Total $ 342,851 $ 65,251 $ 116,668 $ 524,770 (thousands of U.S. dollars) Six Months Ended June 30, 2023 Sterigenics Nordion Nelson Labs Consolidated Point in time $ 326,587 $ 38,241 $ — $ 364,828 Over time — 2,285 108,759 111,044 Total $ 326,587 $ 40,526 $ 108,759 $ 475,872

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2024
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following: (thousands of U.S. dollars) June 30, 2024 December 31, 2023 Raw materials and supplies $ 46,626 $ 43,411 Work-in-process 2,371 471 Finished goods 9,104 4,670 58,101 48,552 Reserve for excess and obsolete inventory (229) (236) Inventories, net $ 57,872 $ 48,316

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	6 Months Ended
	Jun. 30, 2024
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) June 30, 2024 December 31, 2023 Prepaid taxes $ 3,709 $ 4,129 Prepaid business insurance 3,827 7,174 Prepaid rent 1,226 1,150 Customer contract assets 21,599 17,785 Current deposits 501 715 Prepaid maintenance contracts 455 422 Value added tax receivable 3,576 4,306 Prepaid software licensing 2,746 2,503 Stock supplies 3,881 3,669 Embedded derivatives 1,571 1,225 Other 13,561 10,768 Prepaid expenses and other current assets $ 56,652 $ 53,846

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Changes to goodwill during the six months ended June 30, 2024 were as follows: (thousands of U.S. dollars) Sterigenics Nordion Nelson Labs Total Goodwill at December 31, 2023 $ 659,888 $ 276,929 $ 174,373 $ 1,111,190 Changes due to foreign currency exchange rates (3,311) (8,582) (991) (12,884) Goodwill at June 30, 2024 $ 656,577 $ 268,347 $ 173,382 $ 1,098,306
Schedule of Acquired Finite-Lived Intangible Assets	Other intangible assets consisted of the following: (thousands of U.S. dollars) Gross Carrying Amount Accumulated Amortization As of June 30, 2024 Finite-lived intangible assets Customer relationships $ 652,688 $ 511,941 Proprietary technology 75,453 51,222 Trade names 2,545 1,425 Land-use rights 8,529 1,912 Sealed source and supply agreements 202,400 110,243 Other 4,448 3,302 Total finite-lived intangible assets 946,063 680,045 Indefinite-lived intangible assets Regulatory licenses and other (a) 76,229 — Trade names / trademarks 25,691 — Total indefinite-lived intangible assets 101,920 — Total $ 1,047,983 $ 680,045 As of December 31, 2023 Gross Carrying Amount Accumulated Amortization 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 (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.
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 June 30, 2024 Finite-lived intangible assets Customer relationships $ 652,688 $ 511,941 Proprietary technology 75,453 51,222 Trade names 2,545 1,425 Land-use rights 8,529 1,912 Sealed source and supply agreements 202,400 110,243 Other 4,448 3,302 Total finite-lived intangible assets 946,063 680,045 Indefinite-lived intangible assets Regulatory licenses and other (a) 76,229 — Trade names / trademarks 25,691 — Total indefinite-lived intangible assets 101,920 — Total $ 1,047,983 $ 680,045 As of December 31, 2023 Gross Carrying Amount Accumulated Amortization 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 (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.
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) For the remainder of 2024 $ 39,468 2025 42,138 2026 22,039 2027 20,962 2028 20,414 Thereafter 120,997 Total $ 266,018

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: (thousands of U.S. dollars) June 30, 2024 December 31, 2023 Accrued employee compensation $ 30,352 $ 35,037 Georgia EO litigation settlement reserve — 35,000 Illinois EO litigation settlement reserve — 288 Other legal reserves 370 1,480 Accrued interest expense 6,422 26,681 Embedded derivatives 2,508 414 Professional fees 17,367 12,691 Accrued utilities 1,924 2,056 Insurance accrual 3,248 2,922 Accrued taxes 2,337 2,407 Other 4,526 3,495 Accrued liabilities $ 69,054 $ 122,471

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2024
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt consisted of the following: (thousands of U.S. dollars) As of June 30, 2024 Gross Amount Unamortized Debt Issuance Costs Unamortized Debt Discount Net Amount Secured notes due 2031 $ 750,000 $ (3,996) $ — 746,004 Term loan due 2031 1,509,350 (7,002) (23,742) 1,478,606 2,259,350 (10,998) (23,742) 2,224,610 Less current portion 11,320 (51) (177) 11,092 Long-term debt $ 2,248,030 $ (10,947) $ (23,565) $ 2,213,518 (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
Schedule of Maturities of Long-term Debt	Aggregate maturities of the Company’s long-term debt, excluding debt discounts, as of June 30, 2024, are as follows: (thousands of U.S. dollars) 2024 $ 3,773 2025 15,094 2026 15,094 2027 15,094 2028 15,094 Thereafter 2,195,201 Total $ 2,259,350

Employee Benefits (Tables)

Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2024
Postemployment Benefits [Abstract]
Schedule of Net Benefit Costs	The components of net periodic pension benefit for the defined benefit plan for the three and six months ended June 30, 2024 and 2023 were as follows: Three Months Ended June 30, Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 2024 2023 Service cost $ 142 $ 132 $ 287 $ 263 Interest cost 2,612 2,742 5,263 5,466 Expected return on plan assets (3,961) (4,046) (7,980) (8,065) Net periodic benefit $ (1,207) $ (1,172) $ (2,430) $ (2,336) Three Months Ended June 30, Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 2024 2023 Service cost $ 2 $ 2 $ 5 $ 4 Interest cost 85 90 171 180 Amortization of net actuarial gain (33) (44) (66) (88) Net periodic benefit cost $ 54 $ 48 $ 110 $ 96

Other Comprehensive Income (L_2

Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2024
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 – April 1, 2024 $ (7,184) $ (118,737) $ 6,065 $ (119,856) Other comprehensive income (loss) before reclassifications 63 (23,110) 1,177 (21,870) Amounts reclassified from accumulated other comprehensive income (loss) (33) (a) — (3,638) (b) (3,671) Net current-period other comprehensive income (loss) 30 (23,110) (2,461) (25,541) Ending balance – June 30, 2024 $ (7,154) $ (141,847) $ 3,604 $ (145,397) Beginning balance – January 1, 2024 $ (7,297) $ (91,031) $ 5,646 (92,682) Other comprehensive income (loss) before reclassifications 209 (50,816) 5,228 (45,379) Amounts reclassified from accumulated other comprehensive income (loss) (66) (a) — (7,270) (b) (7,336) Net current-period other comprehensive income (loss) 143 (50,816) (2,042) (52,715) Ending balance – June 30, 2024 $ (7,154) $ (141,847) $ 3,604 $ (145,397) (thousands of U.S. dollars) Defined Benefit Plans Foreign Currency Translation Interest Rate Derivatives Total Beginning balance – April 1, 2023 $ 3,158 $ (119,948) $ 12,092 $ (104,698) Other comprehensive income (loss) before reclassifications 62 21,374 10,950 32,386 Amounts reclassified from accumulated other comprehensive income (loss) (44) (a) — (6,948) (6,992) Net current-period other comprehensive income (loss) 18 21,374 4,002 25,394 Ending balance – June 30, 2023 $ 3,176 $ (98,574) $ 16,094 $ (79,304) Beginning balance – January 1, 2023 $ 3,209 $ (131,205) $ 21,343 $ (106,653) Other comprehensive income (loss) before reclassifications 55 32,631 8,555 41,241 Amounts reclassified from accumulated other comprehensive income (loss) (88) (a) — (13,804) (13,892) Net current-period other comprehensive income (loss) (33) 32,631 (5,249) 27,349 Ending balance – June 30, 2023 $ 3,176 $ (98,574) $ 16,094 $ (79,304) (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).

Share-Based Compensation (Table

Share-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2024
Share-Based Payment Arrangement [Abstract]
Schedule of Nonvested Restricted Stock Units Activity	A summary of the activity for the six months ended June 30, 2024 related to the restricted stock awards distributed in respect of the pre-IPO awards (Class B-1 and B-2 Units) is presented below: Restricted Stock - Pre- IPO B-1 Restricted Stock - Pre- IPO B-2 Unvested at December 31, 2023 352,447 987,111 Forfeited (2,650) — Vested (144,795) (987,111) Unvested at June 30, 2024 205,002 —
Schedule of Stock Option Activity	The following table summarizes our stock option activity for the six months ended June 30, 2024: Number of Shares Weighted-average Exercise Price At December 31, 2023 6,972,661 $ 15.17 Granted 1,586,669 14.56 Forfeited (80,751) 19.45 At June 30, 2024 8,478,579 $ 15.02
Schedule of Restricted Stock Activity	The following table summarizes our unvested RSUs activity for the six months ended June 30, 2024: Number of Shares Weighted-average Grant Date Fair Value Unvested at December 31, 2023 2,298,836 $ 13.81 Granted 1,181,863 13.98 Forfeited (48,125) 15.05 Vested (538,939) 17.55 Unvested at June 30, 2024 2,893,635 $ 13.16

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2024
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Our basic and diluted earnings per common share are calculated as follows: Three Months Ended Six Months Ended in thousands of U.S. dollars and share amounts (except per share amounts) June 30, June 30, June 30, June 30, Earnings: Net income $ 8,754 $ 23,513 $ 15,077 $ 26,355 Less: Allocation to participating securities 7 137 33 159 Net income attributable to Sotera Health Company common shareholders $ 8,747 $ 23,376 $ 15,044 $ 26,196 Weighted Average Common Shares: Weighted-average common shares outstanding - basic 282,894 280,893 282,403 280,793 Dilutive effect of potential common shares 1,647 2,254 1,861 2,247 Weighted-average common shares outstanding - diluted 284,541 283,147 284,264 283,040 Earnings per Common Share: Net income per common share attributable to Sotera Health Company common shareholders - basic $ 0.03 $ 0.08 $ 0.05 $ 0.09 Net income per common share attributable to Sotera Health Company common shareholders - diluted 0.03 0.08 0.05 0.09
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Diluted earnings per share does not consider the following potential common shares as the effect would be anti-dilutive: Three Months Ended Six Months Ended in thousands of share amounts June 30, June 30, June 30, June 30, Stock options 5,776 4,283 5,248 3,928 RSUs 1,800 1,308 1,583 1,138 Total anti-dilutive securities 7,576 5,591 6,831 5,066

Financial Instruments and Fin_2

Financial Instruments and Financial Risk (Tables)	6 Months Ended
	Jun. 30, 2024
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: June 30, 2024 December 31, 2023 (in U.S. Dollars; notional in millions, fair value in thousands) Fair Value Fair Value Notional Derivative Derivative Notional Derivative Derivative Derivatives designated as hedging instruments Interest rate caps $ 1,000.0 $ 1,528 — $ 1,000.0 $ 8,763 $ — Interest rate swaps 400.0 3,817 — 400.0 1,487 — Derivatives not designated as hedging instruments Foreign currency forward contracts $ 204.4 $ 84 $ 17 $ 171.0 $ 149 $ 9 Embedded derivatives 136.7 (a) 1,571 2,508 150.1 1,225 405 Total $ 1,741.1 $ 7,000 $ 2,525 $ 1,721.1 $ 11,624 $ 414 (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)	The following table summarizes the activities of our derivative instruments for the periods presented, and the line item in which they are recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss): (thousands of U.S. dollars) Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Realized gain on interest rate derivatives recorded in interest expense, net (a) (4,906) (9,400) (9,802) (18,571) Unrealized loss (gain) on embedded derivatives recorded in other expense (income), net (83) (973) 1,750 (747) Realized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss 1,499 (2,393) 5,507 (1,944) Unrealized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss 653 — 73 (282) (a) Amounts primarily represent quarterly 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 of our financial assets and liabilities: As of June 30, 2024 Fair Value (thousands of U.S. dollars) Carrying Level 1 Level 2 Level 3 Derivatives designated as hedging instruments (a) Interest rate caps $ 1,528 $ — $ 1,528 $ — Interest rate swaps 3,817 — 3,817 — Derivatives not designated as hedging instruments (b) Foreign currency forward contract assets 84 — 84 — Foreign currency forward contract liabilities 17 — 17 — Embedded derivative assets 1,571 — 1,571 — Embedded derivative liabilities 2,508 — 2,508 — Current portion of long-term debt (c) Term loan, due 2031 11,092 — 11,292 — Long-Term Debt (c) Senior secured notes, due 2031 746,004 — 749,100 — Term loan, due 2031 1,467,514 — 1,494,285 — Finance Lease Obligations (with current portion) (d) 96,285 — 96,285 — As of December 31, 2023 Fair Value (thousands of U.S. dollars) Carrying 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 contracts 149 — 149 — Foreign currency forward 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 — (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 and yield curves. (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). 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 the foreign currency exchange rate over the life of the contract. (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 are based upon quoted prices for each Term Loan and the Secured Notes in inactive markets as provided by an independent fixed income security pricing service. (d) Fair value approximates carrying value.

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2024
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Financial information for each of our segments is presented in the following table: Three Months Ended June 30, Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 2024 2023 Segment revenues (a) Sterigenics $ 176,354 $ 166,590 $ 342,851 $ 326,587 Nordion 41,244 31,975 65,251 40,526 Nelson Labs 58,996 56,717 116,668 108,759 Total net revenues $ 276,594 $ 255,282 $ 524,770 $ 475,872 Segment income (b) Sterigenics $ 96,778 $ 91,450 $ 182,596 $ 174,290 Nordion 23,420 17,784 34,205 19,310 Nelson Labs 17,137 19,251 32,478 33,353 Total segment income $ 137,335 $ 128,485 $ 249,279 $ 226,953 (a) Revenues are reported net of intersegment sales. Our Nordion segment recognized $17.9 million and $14.7 million in revenues from sales to our Sterigenics segment for the three months ended June 30, 2024 and 2023, respectively, and $27.9 million and $17.6 million in revenues from sales to our Sterigenics segment for the six months ended June 30, 2024 and 2023, respectively, that is not reflected in net revenues in the table above. Intersegment sales for Sterigenics and Nelson Labs are immaterial for these periods. (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 six months ended June 30, 2024 and 2023 were as follows: Six Months Ended June 30, (thousands of U.S. dollars) 2024 2023 Sterigenics $ 53,798 $ 73,725 Nordion 19,463 16,283 Nelson Labs 3,550 8,126 Total capital expenditures $ 76,811 $ 98,134
Schedule of Reconciliation of Operating Profit (Loss) from Segments to Consolidated	A reconciliation of segment income to consolidated income before taxes is as follows: (thousands of U.S. dollars) Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 Segment income $ 137,335 $ 128,485 $ 249,279 $ 226,953 Less adjustments: Interest expense, net (a) 40,388 30,728 82,159 59,598 Depreciation and amortization (b) 39,830 39,490 80,260 79,028 Share-based compensation (c) 10,206 8,409 18,863 15,757 Loss on refinancing of debt (d) 23,400 — 24,090 — (Gain) loss on foreign currency and derivatives not designated as hedging instruments, net (e) (698) (409) 532 126 Business optimization expenses (f) 593 3,604 647 5,835 Professional services relating to EO sterilization facilities (g) 7,818 11,623 14,157 25,595 Secondary offering costs (h) 20 — 1,137 — Accretion of asset retirement obligation (i) 636 555 1,278 1,127 Consolidated income before taxes $ 15,142 $ 34,485 $ 26,156 $ 39,887 (a) Interest expense, net presented in this reconciliation for the three and six months ended June 30, 2023 has been adjusted to conform to the current year presentation to include interest expense, net on Term Loan B due 2026 attributable to the loan proceeds that were used to fund the $408.0 million Illinois EO litigation settlement. (b) Includes depreciation of Co-60 held at gamma irradiation sites. (c) Represents share-based compensation expense to employees and Non-Employee Directors. (d) Represents the write-off of unamortized debt issuance costs and discounts, as well as certain other costs incurred related to the Refinancing Term Loans and the Secured Notes. The six months ended June 30, 2024 includes $0.7 million of debt refinancing costs related to Amendment No. 3 to the Senior Secured Credit Facilities. (e) Represents the effects of (i) fluctuations in foreign currency exchange rates and (ii) non-cash mark-to-fair value of embedded derivatives relating to certain customer and supply contracts at Nordion. (f) Represents (i) certain costs related to acquisitions and the integration of recent 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) professional fees and other costs associated with business optimization, cost saving and other process enhancement projects, and (v) professional fees, payroll costs, and other costs, including ongoing lease and utility expenses associated with the closure of the Willowbrook, Illinois facility. The six months ended June 30, 2023 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. (g) Represents litigation and other professional fees associated with our EO sterilization facilities. Amounts presented for the three and six months ended June 30, 2023 have been adjusted to exclude interest expense, net associated with Term Loan B due 2026 attributable to the loan proceeds that were used to fund the $408.0 million Illinois EO litigation settlement. (h) Represents expenses incurred in connection with the secondary offering of our common stock that closed on March 4, 2024. (i) Represents non-cash accretion of asset retirement obligations related to Co-60 and gamma 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.

Basis of Presentation (Details)

Basis of Presentation (Details)	6 Months Ended
	Jun. 30, 2024 segment
Accounting Policies [Abstract]
Number of operating segments	3
Number of reportable segments	3

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Total net revenues	$ 276,594	$ 255,282	$ 524,770	$ 475,872
Deferred revenues	12,989		12,989		$ 13,492
Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	217,328	197,243	406,876	364,828
Over time
Disaggregation of Revenue [Line Items]
Total net revenues	59,266	58,039	117,894	111,044
Sterigenics
Disaggregation of Revenue [Line Items]
Total net revenues	176,354	166,590	342,851	326,587
Sterigenics | Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	176,354	166,590	342,851	326,587
Sterigenics | Over time
Disaggregation of Revenue [Line Items]
Total net revenues	0	0	0	0
Nordion
Disaggregation of Revenue [Line Items]
Total net revenues	41,244	31,975	65,251	40,526
Nordion | Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	40,974	30,653	64,025	38,241
Nordion | Over time
Disaggregation of Revenue [Line Items]
Total net revenues	270	1,322	1,226	2,285
Nelson Labs
Disaggregation of Revenue [Line Items]
Total net revenues	58,996	56,717	116,668	108,759
Nelson Labs | Point in time
Disaggregation of Revenue [Line Items]
Total net revenues	0	0	0	0
Nelson Labs | Over time
Disaggregation of Revenue [Line Items]
Total net revenues	$ 58,996	$ 56,717	$ 116,668	$ 108,759

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 46,626	$ 43,411
Work-in-process	2,371	471
Finished goods	9,104	4,670
Inventories, gross	58,101	48,552
Reserve for excess and obsolete inventory	(229)	(236)
Inventories, net	$ 57,872	$ 48,316

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid taxes	$ 3,709	$ 4,129
Prepaid business insurance	3,827	7,174
Prepaid rent	1,226	1,150
Customer contract assets	21,599	17,785
Current deposits	501	715
Prepaid maintenance contracts	455	422
Value added tax receivable	3,576	4,306
Prepaid software licensing	2,746	2,503
Stock supplies	3,881	3,669
Embedded derivatives	1,571	1,225
Other	13,561	10,768
Prepaid expenses and other current assets	$ 56,652	$ 53,846

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2024 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 1,111,190
Changes due to foreign currency exchange rates	(12,884)
Ending balance	1,098,306
Sterigenics
Goodwill [Roll Forward]
Beginning balance	659,888
Changes due to foreign currency exchange rates	(3,311)
Ending balance	656,577
Nordion
Goodwill [Roll Forward]
Beginning balance	276,929
Changes due to foreign currency exchange rates	(8,582)
Ending balance	268,347
Nelson Labs
Goodwill [Roll Forward]
Beginning balance	174,373
Changes due to foreign currency exchange rates	(991)
Ending balance	$ 173,382

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of Acquired Finite-Lived and Indefinite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 946,063	$ 967,350
Accumulated Amortization	680,045	655,562
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	101,920	104,530
Total	1,047,983	1,071,880
Regulatory licenses and other
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 76,229	78,684
Renewal term	10 years
Trade names / trademarks
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 25,691	25,846
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	652,688	657,673
Accumulated Amortization	511,941	485,188
Proprietary technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	75,453	84,918
Accumulated Amortization	51,222	56,846
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,545	2,567
Accumulated Amortization	1,425	1,207
Land-use rights
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,529	8,756
Accumulated Amortization	1,912	1,855
Sealed source and supply agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	202,400	208,919
Accumulated Amortization	110,243	107,561
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,448	4,517
Accumulated Amortization	$ 3,302	$ 2,905

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets			$ 39,879	$ 41,108
Finite-lived intangible assets, remaining amortization period	9 years		9 years
Other
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 19,800	$ 39,900	$ 20,500	41,100
Other | Amortization of Intangible Assets, Nonproduction
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 15,400	$ 31,100	$ 16,100	$ 32,300

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
For the remainder of 2024	$ 39,468
2025	42,138
2026	22,039
2027	20,962
2028	20,414
Thereafter	120,997
Total	$ 266,018

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accounts Payable and Accrued Liabilities [Line Items]
Accrued employee compensation	$ 30,352	$ 35,037
Other legal reserves	370	1,480
Accrued interest expense	6,422	26,681
Embedded derivatives	2,508	414
Professional fees	17,367	12,691
Accrued utilities	1,924	2,056
Insurance accrual	3,248	2,922
Accrued taxes	2,337	2,407
Other	4,526	3,495
Accrued liabilities	69,054	122,471
Ethylene Oxide Tort Litigation – Georgia
Accounts Payable and Accrued Liabilities [Line Items]
Litigation settlement reserve	0	35,000
Ethylene Oxide Tort Litigation - Illinois
Accounts Payable and Accrued Liabilities [Line Items]
Litigation settlement reserve	$ 0	$ 288

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Total	$ 2,259,350	$ 2,260,600
Less current portion	11,320	5,000
Long-term debt	2,248,030	2,255,600
Unamortized Debt Issuance Costs	(10,998)	(9,222)
Less current portion	(51)	(76)
Long-term debt	(10,947)	(9,146)
Unamortized discount, excluding current portion	(23,742)	(22,907)
Less current portion	(177)	(127)
Unamortized Debt Discount	(23,565)	(22,780)
Net Amount	2,224,610	2,228,471
Less current portion	11,092	4,797
Long-term debt	2,213,518	2,223,674
Secured Debt | Secured notes due 2031
Debt Instrument [Line Items]
Total	750,000
Unamortized Debt Issuance Costs	(3,996)
Unamortized Debt Discount	0
Net Amount	746,004
Secured Debt | Term loan due 2031
Debt Instrument [Line Items]
Total	1,509,350
Unamortized Debt Issuance Costs	(7,002)
Unamortized Debt Discount	(23,742)
Net Amount	1,478,606
Secured Debt | Term loan, due 2026
Debt Instrument [Line Items]
Total	1,763,100	1,763,100
Unamortized Debt Issuance Costs		(1,606)
Unamortized Debt Discount		(10,298)
Net Amount		1,751,196
Secured Debt | Term loan B, due 2026
Debt Instrument [Line Items]
Total	$ 496,300	497,500
Unamortized Debt Issuance Costs		(7,616)
Unamortized Debt Discount		(12,609)
Net Amount		$ 477,275

Long-Term Debt - Senior Secured

Long-Term Debt - Senior Secured Credit Facilities (Narrative) (Details)		3 Months Ended	6 Months Ended
	May 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Mar. 01, 2024 USD ($)	Dec. 13, 2019 USD ($)
Ethylene Oxide Tort Litigation - Illinois | Pending Litigation
Debt Instrument [Line Items]
Base amount for default		$ 162,600,000	$ 162,600,000
Basis spread adjustment		30%	30%
Triggering period for default			60 days
Secured notes due 2031 | Senior Notes
Debt Instrument [Line Items]
Face amount	$ 750,000,000
Debt instrument, stated percentage	7.375%
Redemption price, as percent of principal, proceeds from equity offerings	107.375%
Secured notes due 2031 | Senior Notes | Maximum
Debt Instrument [Line Items]
Percentage of original principal that may be redeemed	40%
Redemption as percent of outstanding principal amount	10%
Secured notes due 2031 | Senior Notes | Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, percentage	100%
Secured notes due 2031 | Senior Notes | Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Redemption price, percentage	103%
Term loan B, due 2026 | Senior Secured Credit Facilities
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,509,400,000				$ 423,800,000
Debt instrument, applicable floor interest rate	0
Pricing step-down, percent	0.25%
Leverage ratio	3.30
Soft call premium, percent	1%
Amortization rate	1%
Interest rate		8.58%
Letters of credit outstanding, amount		$ 23,700,000	$ 23,700,000
Unused borrowing capacity		$ 400,100,000	$ 400,100,000
Term loan B, due 2026 | Senior Secured Credit Facilities | Alternative Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Term loan B, due 2026 | Senior Secured Credit Facilities | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate	3.25%
Term loan B, due 2026 | First Lien Notes due 2026
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 83,000,000
Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity				$ 37,500,000

Long-Term Debt - Schedule of Ma

Long-Term Debt - Schedule of Maturities of Long-term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Disclosure [Abstract]
2024	$ 3,773
2025	15,094
2026	15,094
2027	15,094
2028	15,094
Thereafter	2,195,201
Total	$ 2,259,350	$ 2,260,600

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Effective income tax rate	42.20%	31.80%	42.40%	33.90%

Employee Benefits - Schedule of

Employee Benefits - Schedule of Net Benefit Costs (Details) - Nordion - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 142	$ 132	$ 287	$ 263
Interest cost	2,612	2,742	5,263	5,466
Expected return on plan assets	(3,961)	(4,046)	(7,980)	(8,065)
Net periodic (benefit) cost	(1,207)	(1,172)	(2,430)	(2,336)
Other Benefits Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	5	4
Interest cost	85	90	171	180
Amortization of net actuarial gain	(33)	(44)	(66)	(88)
Net periodic (benefit) cost	$ 54	$ 48	$ 110	$ 96

Employee Benefits - Narrative (

Employee Benefits - Narrative (Details) - Defined Benefit Pension Plan - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Actual funding requirements, period	5 years
Nordion
Defined Benefit Plan Disclosure [Line Items]
Letters of credit outstanding, amount	$ 15.9	$ 16
Maximum
Defined Benefit Plan Disclosure [Line Items]
Solvency payment as percent of market value	15%

Other Comprehensive Income (L_3

Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 429,392	$ 361,125	$ 443,734	$ 350,238
Other comprehensive income (loss) before reclassifications	(21,870)	32,386	(45,379)	41,241
Amounts reclassified from accumulated other comprehensive income (loss)	(3,671)	(6,992)	(7,336)	(13,892)
Net current-period other comprehensive income (loss)	(25,541)	25,394	(52,715)	27,349
Ending balance	422,764	418,367	422,764	418,367
Defined Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(7,184)	3,158	(7,297)	3,209
Other comprehensive income (loss) before reclassifications	63	62	209	55
Amounts reclassified from accumulated other comprehensive income (loss)	(33)	(44)	(66)	(88)
Net current-period other comprehensive income (loss)	30	18	143	(33)
Ending balance	(7,154)	3,176	(7,154)	3,176
Foreign Currency Translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(118,737)	(119,948)	(91,031)	(131,205)
Other comprehensive income (loss) before reclassifications	(23,110)	21,374	(50,816)	32,631
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Net current-period other comprehensive income (loss)	(23,110)	21,374	(50,816)	32,631
Ending balance	(141,847)	(98,574)	(141,847)	(98,574)
Interest Rate Derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	6,065	12,092	5,646	21,343
Other comprehensive income (loss) before reclassifications	1,177	10,950	5,228	8,555
Amounts reclassified from accumulated other comprehensive income (loss)	(3,638)	(6,948)	(7,270)	(13,804)
Net current-period other comprehensive income (loss)	(2,461)	4,002	(2,042)	(5,249)
Ending balance	3,604	16,094	3,604	16,094
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(119,856)	(104,698)	(92,682)	(106,653)
Ending balance	$ (145,397)	$ (79,304)	$ (145,397)	$ (79,304)

Share-Based Compensation - Narr

Share-Based Compensation - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 9.8	$ 7.9	$ 18.1	$ 14.7
Restricted Stock | 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	0.4	0.5	$ 0.8	1
Restricted Stock | Restricted Stock - Pre- IPO B-1 | Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			20%
Restricted Stock | Restricted Stock - Pre- IPO B-1 | Year Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			20%
Restricted Stock | Restricted Stock - Pre- IPO B-1 | Year Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			20%
Restricted Stock | Restricted Stock - Pre- IPO B-1 | Year Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			20%
Restricted Stock | Restricted Stock - Pre- IPO B-1 | Year Five
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			20%
Restricted Stock | Restricted Stock - Pre- IPO B-2 | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Investment, internal rate of return			20%
Return on investment			250%
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term			10 years
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
Stock Options | 2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	4.6	3.7	$ 8.6	6.8
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
RSUs | 2020 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 5.2	$ 4.2	$ 9.5	$ 7.9

Share-Based Compensation - Sche

Share-Based Compensation - Schedule of Nonvested Restricted Stock Units Activity (Details) - Restricted Stock	6 Months Ended
	Jun. 30, 2024 shares
Restricted Stock - Pre- IPO B-1
Number of Shares
Beginning balance (in shares)	352,447
Forfeited (in shares)	(2,650)
Vested (in shares)	(144,795)
Ending balance (in shares)	205,002
Restricted Stock - Pre- IPO B-2
Number of Shares
Beginning balance (in shares)	987,111
Forfeited (in shares)	0
Vested (in shares)	(987,111)
Ending balance (in shares)	0

Share-Based Compensation - Sc_2

Share-Based Compensation - Schedule of Stock Option Activity (Details) - Stock Options $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2024 USD ($) $ / shares shares
Number of Shares
Beginning balance (in shares) | shares	6,972,661
Granted (in shares) | shares	1,586,669
Forfeited (in shares) | shares	(80,751)
Ending balance (in shares) | shares	8,478,579
Weighted-average Exercise Price
Beginning balance (in shares) | $ / shares	$ 15.17
Granted (in dollars per share) | $ / shares	14.56
Forfeited (in dollars per share) | $ / shares	19.45
Ending balance (in shares) | $ / shares	$ 15.02
Options vested (in shares) | $	$ 4.2
Options exercisable (in shares) | $	$ 4.2

Share-Based Compensation - Sc_3

Share-Based Compensation - Schedule of Restricted Stock Activity (Details) - RSUs	6 Months Ended
	Jun. 30, 2024 $ / shares shares
Number of Shares
Beginning balance (in shares) | shares	2,298,836
Granted (in shares) | shares	1,181,863
Forfeited (in shares) | shares	(48,125)
Vested (in shares) | shares	(538,939)
Ending balance (in shares) | shares	2,893,635
Weighted-average Grant Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 13.81
Granted (in dollars per share) | $ / shares	13.98
Forfeited (in dollars per share) | $ / shares	15.05
Vested (in dollars per share) | $ / shares	17.55
Ending balance (in dollars per share) | $ / shares	$ 13.16

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings:
Net income	$ 8,754	$ 23,513	$ 15,077	$ 26,355
Less: Allocation to participating securities	7	137	33	159
Less: Allocation to participating securities	7	137	33	159
Net income attributable to Sotera Health Company common shareholders	8,747	23,376	15,044	26,196
Net income attributable to Sotera Health Company common shareholders	$ 8,747	$ 23,376	$ 15,044	$ 26,196
Weighted Average Common Shares:
Weighted-average common shares outstanding - basic (in shares)	282,894	280,893	282,403	280,793
Dilutive effect of potential common shares (in shares)	1,647	2,254	1,861	2,247
Weighted-average common shares outstanding - diluted (in shares)	284,541	283,147	284,264	283,040
Earnings per Common Share:
Net income per common share attributable to Sotera Health Company common shareholders - basic (in dollars per share)	$ 0.03	$ 0.08	$ 0.05	$ 0.09
Net income per common share attributable to Sotera Health Company common shareholders - diluted (in dollars per share)	$ 0.03	$ 0.08	$ 0.05	$ 0.09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,576	5,591	6,831	5,066
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,776	4,283	5,248	3,928
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	1,800	1,308	1,583	1,138

Commitment and Contingencies (D

Commitment and Contingencies (Details) $ in Millions				6 Months Ended
	Jan. 09, 2023 segment	Aug. 31, 2022 USD ($)	Aug. 21, 2020 plaintiff	Jun. 30, 2024 USD ($) claim case
Gain Contingencies [Line Items]
Loss contingency, insurance limits per occurrence | $				$ 10
Loss contingency, insurance limits | $				$ 20
GEORGIA | Personal Injury
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]
Defense incurred costs | $		$ 110.2
Pending Litigation | GEORGIA | Personal Injury And Wrongful Death
Gain Contingencies [Line Items]
Number of pending claims | claim				280
Pending Litigation | GEORGIA | Personal Injury
Gain Contingencies [Line Items]
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
Ethylene Oxide Tort Litigation - Illinois | Pending Litigation
Gain Contingencies [Line Items]
Number of plaintiffs | plaintiff			40
Asset Transfer Case | Pending Litigation | GEORGIA
Gain Contingencies [Line Items]
Number of new claims filed | segment	365
Ethylene Oxide Tort Litigation – Georgia | GEORGIA | Property Devaluation
Gain Contingencies [Line Items]
Number of new claims filed | case				9

Financial Instruments and Fin_3

Financial Instruments and Financial Risk - Narrative (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Mar. 31, 2023 USD ($)	May 31, 2022 USD ($) instrument	Oct. 31, 2021 USD ($) instrument
Derivative [Line Items]
Notional amount	$ 1,741,100,000		$ 1,741,100,000		$ 1,741,100,000	$ 1,721,100,000
Interest rate derivatives, net of tax	(2,461,000)	$ 4,002,000	(2,042,000)	$ (5,249,000)
Allowance for uncollectible accounts	3,111,000		3,111,000		3,111,000	4,689,000
Derivatives Designated in Hedge Relationships
Derivative [Line Items]
Interest rate derivatives, net of tax					4,800,000
Interest Rate Swap | Derivatives Designated in Hedge Relationships
Derivative [Line Items]
Notional amount	400,000,000		400,000,000		400,000,000	400,000,000	$ 400,000,000
Interest Rate Cap | Derivatives Designated in Hedge Relationships
Derivative [Line Items]
Number of instruments held | instrument								2	2
Notional amount	$ 1,000,000,000		$ 1,000,000,000		$ 1,000,000,000	$ 1,000,000,000			$ 1,000,000,000
Option premium								$ 4,100,000	$ 1,800,000
Interest Rate Cap | Derivatives Designated in Hedge Relationships | SOFR
Derivative [Line Items]
Percent of borrowing limitation due to cash flow exposure								3.50%
Interest Rate Cap | Derivatives Designated in Hedge Relationships | LIBOR
Derivative [Line Items]
Percent of borrowing limitation due to cash flow exposure									1%

Financial Instruments and Fin_4

Financial Instruments and Financial Risk - Schedule of Derivative Instruments (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023	Mar. 31, 2023	May 31, 2022	Oct. 31, 2021
Derivative [Line Items]
Notional Amount	$ 1,741,100,000	$ 1,721,100,000
Fair value, derivative assets	7,000,000	11,624,000
Fair value, derivative liabilities	2,525,000	414,000
Derivatives designated as hedging instruments | Interest rate caps
Derivative [Line Items]
Notional Amount	1,000,000,000	1,000,000,000			$ 1,000,000,000
Fair value, derivative assets	1,528,000	8,763,000
Fair value, derivative liabilities	0	0
Derivatives designated as hedging instruments | Interest rate caps | Forward Start Date Beginning on July 31, 2023
Derivative [Line Items]
Notional Amount				$ 1,000,000,000
Derivatives designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Notional Amount	400,000,000	400,000,000	$ 400,000,000
Fair value, derivative assets	3,817,000	1,487,000
Fair value, derivative liabilities	0	0
Derivatives not designated as hedging instruments | Foreign currency forward contracts
Derivative [Line Items]
Notional Amount	204,400,000	171,000,000
Fair value, derivative assets	84,000	149,000
Fair value, derivative liabilities	17,000	9,000
Derivatives not designated as hedging instruments | Embedded derivatives
Derivative [Line Items]
Notional Amount	136,700,000	150,100,000
Fair value, derivative assets	1,571,000	1,225,000
Fair value, derivative liabilities	$ 2,508,000	$ 405,000

Financial Instruments and Fin_5

Financial Instruments and Financial Risk - Schedule of Derivative Instruments, Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives			$ 1,750	$ (747)
Interest Rate Cap
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain on interest rate derivatives recorded in interest expense, net	$ (4,906)	$ (9,400)	(9,802)	(18,571)
Embedded Derivative
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	(83)	(973)	1,750	(747)
Foreign currency forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss	1,499	(2,393)	5,507	(1,944)
Unrealized loss (gain) on foreign currency forward contracts recorded in foreign exchange (gain) loss	$ 653	$ 0	$ 73	$ (282)

Financial Instruments and Fin_6

Financial Instruments and Financial Risk - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative asset	$ 7,000	$ 11,624
Derivative liabilities	2,525	414
Derivatives designated as hedging instruments | Interest rate caps
Derivative [Line Items]
Derivative asset	1,528	8,763
Derivative liabilities	0	0
Derivatives designated as hedging instruments | Interest rate caps | Level 1
Derivative [Line Items]
Derivative asset	0	0
Derivatives designated as hedging instruments | Interest rate caps | Level 2
Derivative [Line Items]
Derivative asset	1,528	8,763
Derivatives designated as hedging instruments | Interest rate caps | Level 3
Derivative [Line Items]
Derivative asset	0	0
Derivatives designated as hedging instruments | Interest rate swaps
Derivative [Line Items]
Derivative asset	3,817	1,487
Derivative liabilities	0	0
Derivatives designated as hedging instruments | Interest rate swaps | Level 1
Derivative [Line Items]
Derivative asset	0	0
Derivatives designated as hedging instruments | Interest rate swaps | Level 2
Derivative [Line Items]
Derivative asset	3,817	1,487
Derivatives designated as hedging instruments | Interest rate swaps | Level 3
Derivative [Line Items]
Derivative asset	0	0
Derivatives designated as hedging instruments | Carrying Amount | Interest rate caps
Derivative [Line Items]
Derivative asset	1,528	8,763
Derivatives designated as hedging instruments | Carrying Amount | Interest rate swaps
Derivative [Line Items]
Derivative asset	3,817	1,487
Derivatives not designated as hedging instruments | Term loan due 2031 | Level 1
Derivative [Line Items]
Current portion of long-term debt	0
Long-term debt	0
Derivatives not designated as hedging instruments | Term loan due 2031 | Level 2
Derivative [Line Items]
Current portion of long-term debt	11,292
Long-term debt	1,494,285
Derivatives not designated as hedging instruments | Term loan due 2031 | Level 3
Derivative [Line Items]
Current portion of long-term debt	0
Long-term debt	0
Derivatives not designated as hedging instruments | Secured notes due 2031 | Level 1
Derivative [Line Items]
Long-term debt	0
Derivatives not designated as hedging instruments | Secured notes due 2031 | Level 2
Derivative [Line Items]
Long-term debt	749,100
Derivatives not designated as hedging instruments | Secured notes due 2031 | Level 3
Derivative [Line Items]
Long-term debt	0
Derivatives not designated as hedging instruments | Term loan B, due 2026 | Level 1
Derivative [Line Items]
Current portion of long-term debt		0
Long-term debt		0
Derivatives not designated as hedging instruments | Term loan B, due 2026 | Level 2
Derivative [Line Items]
Current portion of long-term debt		5,000
Long-term debt		492,500
Derivatives not designated as hedging instruments | Term loan B, due 2026 | Level 3
Derivative [Line Items]
Current portion of long-term debt		0
Long-term debt		0
Derivatives not designated as hedging instruments | Term loan, due 2026 | Level 1
Derivative [Line Items]
Long-term debt		0
Derivatives not designated as hedging instruments | Term loan, due 2026 | Level 2
Derivative [Line Items]
Long-term debt		1,758,163
Derivatives not designated as hedging instruments | Term loan, due 2026 | Level 3
Derivative [Line Items]
Long-term debt		0
Derivatives not designated as hedging instruments | Finance Lease Obligations (with current portion) | Level 1
Derivative [Line Items]
Long-term debt	0	0
Derivatives not designated as hedging instruments | Finance Lease Obligations (with current portion) | Level 2
Derivative [Line Items]
Long-term debt	96,285	72,564
Derivatives not designated as hedging instruments | Finance Lease Obligations (with current portion) | Level 3
Derivative [Line Items]
Long-term debt	0	0
Derivatives not designated as hedging instruments | Foreign currency forward contracts | Level 1
Derivative [Line Items]
Derivative asset	0	0
Derivative liabilities	0	0
Derivatives not designated as hedging instruments | Foreign currency forward contracts | Level 2
Derivative [Line Items]
Derivative asset	84	149
Derivative liabilities	17	9
Derivatives not designated as hedging instruments | Foreign currency forward contracts | Level 3
Derivative [Line Items]
Derivative asset	0	0
Derivative liabilities	0	0
Derivatives not designated as hedging instruments | Embedded Derivative Assets and Liabilities
Derivative [Line Items]
Derivative asset	1,571	1,225
Derivative liabilities	2,508	405
Derivatives not designated as hedging instruments | Embedded Derivative Assets and Liabilities | Level 1
Derivative [Line Items]
Derivative asset	0	0
Derivative liabilities	0	0
Derivatives not designated as hedging instruments | Embedded Derivative Assets and Liabilities | Level 2
Derivative [Line Items]
Derivative asset	1,571	1,225
Derivative liabilities	2,508	405
Derivatives not designated as hedging instruments | Embedded Derivative Assets and Liabilities | Level 3
Derivative [Line Items]
Derivative asset	0	0
Derivative liabilities	0	0
Derivatives not designated as hedging instruments | Carrying Amount | Term loan due 2031
Derivative [Line Items]
Current portion of long-term debt	11,092
Long-term debt	1,467,514
Derivatives not designated as hedging instruments | Carrying Amount | Secured notes due 2031
Derivative [Line Items]
Long-term debt	746,004
Derivatives not designated as hedging instruments | Carrying Amount | Term loan B, due 2026
Derivative [Line Items]
Current portion of long-term debt		4,797
Long-term debt		472,477
Derivatives not designated as hedging instruments | Carrying Amount | Term loan, due 2026
Derivative [Line Items]
Long-term debt		1,751,197
Derivatives not designated as hedging instruments | Carrying Amount | Finance Lease Obligations (with current portion)
Derivative [Line Items]
Long-term debt	96,285	72,564
Derivatives not designated as hedging instruments | Carrying Amount | Foreign currency forward contracts
Derivative [Line Items]
Derivative asset	84	149
Derivative liabilities	17	9
Derivatives not designated as hedging instruments | Carrying Amount | Embedded Derivative Assets and Liabilities
Derivative [Line Items]
Derivative asset	1,571	1,225
Derivative liabilities	$ 2,508	$ 405

Segment Information - Narrative

Segment Information - Narrative (Details) - segment	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting [Abstract]
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	20.60%	31.30%	20%	26.30%
Operating Segments | Nordion | Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Customer Two
Segment Reporting Information [Line Items]
Percentage	17%	13.40%	12.80%	17.50%
Operating Segments | Nordion | Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Customer Three
Segment Reporting Information [Line Items]
Percentage	10.50%	12.50%	12.40%	10.70%
Operating Segments | Nordion | Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Customer Four
Segment Reporting Information [Line Items]
Percentage		10.70%	10%	10.10%
Operating Segments | Nordion | Revenue from Contract with Customer Benchmark | Customer Concentration Risk | Customer Five
Segment Reporting Information [Line Items]
Percentage		10.70%

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Segment revenues	$ 276,594	$ 255,282	$ 524,770	$ 475,872
Segment income	137,335	128,485	249,279	226,953
Sterigenics
Segment Reporting Information [Line Items]
Segment revenues	176,354	166,590	342,851	326,587
Nordion
Segment Reporting Information [Line Items]
Segment revenues	41,244	31,975	65,251	40,526
Nelson Labs
Segment Reporting Information [Line Items]
Segment revenues	58,996	56,717	116,668	108,759
Operating Segments
Segment Reporting Information [Line Items]
Segment income	137,335	128,485	249,279	226,953
Total capital expenditures			76,811	98,134
Operating Segments | Sterigenics
Segment Reporting Information [Line Items]
Segment revenues	176,354	166,590	342,851	326,587
Segment income	96,778	91,450	182,596	174,290
Total capital expenditures			53,798	73,725
Operating Segments | Nordion
Segment Reporting Information [Line Items]
Segment revenues	41,244	31,975	65,251	40,526
Segment income	23,420	17,784	34,205	19,310
Total capital expenditures			19,463	16,283
Operating Segments | Nelson Labs
Segment Reporting Information [Line Items]
Segment revenues	58,996	56,717	116,668	108,759
Segment income	17,137	19,251	32,478	33,353
Total capital expenditures			3,550	8,126
Intersegment
Segment Reporting Information [Line Items]
Segment revenues	$ 17,900	$ 14,700	$ 27,900	$ 17,600

Segment Information - Schedul_2

Segment Information - Schedule of Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 09, 2023	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Segment income		$ 137,335	$ 128,485	$ 249,279	$ 226,953
Accretion of asset retirement obligations				1,278	1,127
Net income		8,754	23,513	15,077	26,355
Cancellation fee received from a tenant in connection with the termination				1,000
Revolving Credit Facility
Segment Reporting Information [Line Items]
Debt refinancing costs				700
Ethylene Oxide Tort Litigation - Illinois | Pending Litigation
Segment Reporting Information [Line Items]
Litigation settlement amount awarded to other party	$ 408,000
Operating Segments
Segment Reporting Information [Line Items]
Segment income		137,335	128,485	249,279	226,953
Segment Reconciling Items
Segment Reporting Information [Line Items]
Interest expense, net		40,388	30,728	82,159	59,598
Depreciation and amortization		39,830	39,490	80,260	79,028
Share-based compensation expense		10,206	8,409	18,863	15,757
Loss on refinancing of debt		23,400	0	24,090	0
Gain on foreign currency and derivatives not designated as hedging instruments, net		(698)	(409)	532	126
Business optimization project expenses		593	3,604	647	5,835
Professional services and other expenses relating to EO sterilization facilities		7,818	11,623	14,157	25,595
Secondary offering costs		20	0	1,137	0
Accretion of asset retirement obligations		636	555	1,278	1,127
Net income		$ 15,142	$ 34,485	$ 26,156	$ 39,887