Sotera Health: Second Quarter 2025 Earnings Results

Sotera Health: Second Quarter 2025 Earnings Results

• 1. © 2025 Sotera Health Company | All Rights Reserved. Safeguarding Global Health® Second-Quarter 2025 Earnings Results August 8, 2025

• 2. © 2025 Sotera Health Company | All Rights Reserved. Cautionary Note Regarding Forward-Looking Statements and Non-GAAP Financial Measures 1 Unless expressly indicated or the context requires otherwise, the terms “Sotera Health,” “Company,” “we,” “us,” and “our” in this document refer to Sotera Health Company, a Delaware corporation, and, where appropriate, its subsidiaries on a consolidated basis. This release contains forwardlooking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and reflects management’s expectations about future events and the Company’s operating plans and performance and speak only as of the date hereof. Forward-looking statements present our current forecasts and estimates of future events. These statements do not strictly relate to historical or current results and can be identified by words such as “anticipate,” “appear,” “assume,” “believe,” “estimate,” “expect,” “forecast,” “intend,” “likely,” “may,” “plan,” “project,” “seek,” “should,” “strategy,” “will” and other terms of similar meaning or import in connection with any discussion of future operating, financial or other performance. These forward-looking statements are subject to risks, uncertainties and other factors and actual results may differ materially from those results projected in the statements. These forward-looking statements are subject to various risks, uncertainties and assumptions relating to our operations, financial results, financial condition, business, prospects, growth strategy and liquidity. These risks and uncertainties include, but are not limited to, a disruption in the availability or supply of, or increases in the price of, EO, Co-60 or our other direct materials, services and supplies, including as a result of geopolitical instability and/or sanctions against Russia by the United States, Canada, United Kingdom and/or the European Union; fluctuations in foreign currency exchange rates; evolving changes in environmental, health and safety regulations or preferences, and general economic, social and business conditions; health and safety risks associated with the use, storage, transportation and disposal of potentially hazardous materials such as EO and Co-60; the impact and outcome of current and future legal proceedings and liability claims, including litigation related to the use, emissions and releases of EO from our facilities in California, Georgia, Illinois and New Mexico and the possibility that additional claims will be made in the future relating to these or other facilities; our ability to satisfy the conditions for settlement of the EO claims related to our former facility in Willowbrook, Illinois; allegations of our failure to properly perform services and potential product liability claims, recalls, penalties and reputational harm; compliance with the extensive regulatory requirements to which we are subject, the related costs, and any failures to receive or maintain, or delays in receiving, required clearances or approvals; adverse changes in industry trends; competition we face; market conditions and changes, including inflationary trends and the impact of tariffs, that impact our long-term supply contracts with variable price clauses and increase our cost of revenues; business continuity hazards, including supply chain disruptions and other risks associated with our operations; the risks of doing business internationally, including global and regional economic and political instability and compliance with various applicable laws and potentially inconsistent laws and regulations in multiple jurisdictions; our ability to increase capacity at existing facilities, build new facilities in a timely and cost-effective manner and renew leases for our leased facilities; our ability to attract and retain qualified employees; severe health events or environmental events; cybersecurity incidents, unauthorized data disclosures, and our dependence on information technology systems; an inability to pursue strategic transactions, find suitable acquisition targets, or integrate strategic acquisitions into our business successfully; our ability to maintain effective internal control over financial reporting; our reliance on intellectual property to maintain our competitive position and the risk of claims from third parties that we have infringed or misappropriated, or are infringing or misappropriating, their intellectual property rights; our ability to comply with rapidly evolving data privacy and security laws and regulations in various jurisdictions and any ineffective compliance efforts with such laws and regulations; our ability to generate profitability in future periods; impairment charges on our goodwill and other intangible assets with indefinite lives, as well as other long-lived assets and intangible assets with definite lives; the effects of unionization efforts and labor regulations in countries in which we operate; adverse changes to our tax positions in U.S. or non-U.S. jurisdictions or the interpretation and application of U.S. tax legislation or other changes in U.S. or non-U.S. taxation of our operations; and our significant leverage and how this significant leverage could adversely affect our ability to raise additional capital, limit our ability to react to challenges confronting our Company or broader changes in our industry or the economy, limit our flexibility in operating our business through restrictions contained in our debt agreements and/or prevent us from meeting our obligations under our existing and future agreements governing our indebtedness. For additional discussion of these risks and uncertainties, please refer to the Company’s filings with the Securities and Exchange Commission, such as its Annual Report on Form 10-K and quarterly reports. We do not undertake any obligation to publicly update or revise these forward-looking statements, except as otherwise required by law. This presentation includes Adjusted EBITDA, Adjusted EBITDA Margin, Tax Rate Applicable to Adjusted Net Income, Adjusted Net Income, Adjusted EPS, Net Debt and Net Leverage Ratio, which are unaudited financial measures that are not based on any standardized methodology prescribed by GAAP. Adjusted EBITDA, Adjusted EBITDA Margin, Tax Rate Applicable to Adjusted Net Income, Adjusted Net Income, Adjusted EPS, Net Debt and Net Leverage Ratio may be calculated differently from, and therefore may not be comparable to, similarly titled measures used by other companies. Adjusted EBITDA, Adjusted EBITDA Margin, Tax Rate Applicable to Adjusted Net Income, Adjusted Net Income, Adjusted EPS, Net Debt and Net Leverage Ratio should not be considered in isolation from, or as a substitute for, financial information prepared in accordance with GAAP. This presentation refers to, and in other communications with investors the Company may refer to, net sales or revenues or other historical financial information on a “constant currency” basis, which is a non-GAAP financial measure defined in the Appendix to this presentation. We use these non-GAAP financial measures as the principal measures of our operating performance. Management believes these measures allow management to more effectively evaluate our operating performance and compare the results of our operations from period to period without the impact of certain non-cash items and non-routine items that we do not expect to continue at the same level in the future and other items that are not core to our operations. We believe that these measures are useful to our investors because they provide a more complete understanding of the factors and trends affecting our business than could be obtained without these measures and their disclosure. In addition, we believe these measures will assist investors in making comparisons to our historical operating results and analyzing the underlying performance of our operations for the periods presented. Our management also uses these measurements in their financial analysis and operational decision-making and Adjusted EBITDA serves as the key metric for the attainment of our primary annual incentive program. These measures may be calculated differently from, and therefore may not be comparable to, a similarly titled measure used by other companies. The Company does not provide a reconciliation for non-GAAP financial measures on a forward-looking basis where it is unable to provide a meaningful or accurate calculation or estimation of reconciling items without unreasonable effort. The Company cannot reconcile its expected Adjusted EBITDA, Tax Rate Applicable to Adjusted Net Income, Adjusted Net Income, Adjusted EPS and Net Leverage Ratio without unreasonable effort because certain items that impact net income, earnings per share and other reconciling metrics are out of the Company’s control and/or cannot be reasonably predicted at this time, including uncertainties caused by changes to the regulatory landscape, restructuring items and certain fair value measurements, all of which are potential adjustments for future earnings. This presentation also contains estimates and other statistical data made by independent parties and by the Company relating to market size and growth and other data about the Company’s industry and estimated total and serviceable addressable markets. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. We have not independently verified this market data. While we are not aware of any misstatements regarding any industry or similar data presented herein, such data involve risks and uncertainties and are subject to change based on various factors, including those described under the headings of “Risk Factors” and “Cautionary Note Regarding Forward-Looking Statements” in the Company’s Annual Report on Form 10-K, and in the Company’s other SEC filings. In addition, projections, assumptions and estimates of the Company’s future performance and the future performance of the markets in which the Company operates are necessarily subject to a high degree of uncertainty and risk. The Sotera Health name, our logo and other trademarks mentioned in this presentation are the property of their respective owners. All Company data and financial information included in this presentation is as of June 30, 2025, unless otherwise stated.

• 3. © 2025 Sotera Health Company | All Rights Reserved. Speakers Michael B. Petras, Jr. Chairman and Chief Executive Officer Jonathan M. Lyons Senior Vice President and Chief Financial Officer 2

• 4. © 2025 Sotera Health Company | All Rights Reserved. Safeguarding Global Health® 3 Strong cash flow generation and disciplined capital allocation Trusted partnerships with blue-chip customers Customers include 40+ of top 50 medical device companies, and 9 of top 10 pharmaceutical companies(1) 70%+ of revenue tied to multiyear contracts(1) Customer relationships average 10+ years across top 25 customers ~5,000 customers in over 50 countries Over 3,000 employees Provide end-to-end solutions for our customers in highly-regulated markets Integrated global network of 62 facilities located in 13 countries (1) For the year ended December 31, 2024.

• 5. © 2025 Sotera Health Company | All Rights Reserved. Our Role in the Healthcare Supply Chain 4 R&D, materials and packaging optimization Pre-FDA filing tests and clinical trials Product manufacturing Sterilization Quality control tests Distribution ✓ ✓ ✓ ✓✓ ✓✓ ✓ ✓✓✓ ✓✓

• 6. © 2025 Sotera Health Company | All Rights Reserved. 48% 37% 15% Routine Validation Expert Advisory Services Three Integrated and Outstanding Business Segments 5 Providing customers end-to-end solutions across the Cobalt-60 supply chain Microbiology and analytical chemistry services include 900+ tests (1) For the year ended December 31, 2024. 2,000+ Customers(1) • Over 40 of the 50 top medical device companies(1) • 9 of the 10 top pharmaceutical companies(1) 48 facilities located across 13 countries and 4 continents ~3,000 customers(1) trust our quality and reliabilityto help ensure lifesaving products are safe Global leader in comprehensive sterilization solutions 49% 39% 12% Gamma EO E-beam Sterigenics Technology Mix(1) World’s Largest Provider of Cobalt-60 sealed sources Global leader in microbiological and analytical lab testing One of a Kind, CNSC licensed, Class 1B nuclear processing facility Providing 2,000+ customers(1) peace of mind through quality, reliability, and safety Nelson Labs Service Mix(1) ~30% ~70% Cobalt-60 sterilization All other technologies Global Cobalt-60 Single-Use Medical Device Sterilization Split

• 7. © 2025 Sotera Health Company | All Rights Reserved. 0% 25% 50% 75% 100% $0 $200 $400 $600 $800 $1,000 $1,200 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Revenue Our business model has demonstrated resilience through consistent revenue growth every year since 2005, including the great recession of 2008 and the COVID pandemic Sotera Health Revenue Growth 6

• 8. © 2025 Sotera Health Company | All Rights Reserved. Our Mission in Action: Safeguarding Global Health® • Together, Sterigenics and Nelson Labs play a critical role in patient safety and supporting FDA approval of groundbreaking treatments. • From validation testing—such as biocompatibility and packaging, to routine sterilization, our teams contributed to the launch of new infusion sets for advanced Parkinson's therapy. • This innovative drug delivery device helps improve quality of life by managing tremors and rigid body movements. • Our expertise helps customers commercialize new products and is a great example of how we play an essential role in Safeguarding Global Health®. One Example of How We Live Our Mission Every Day 7

• 9. © 2025 Sotera Health Company | All Rights Reserved. Q2 2025 Highlights 8 (1) This is a non-GAAP financial measure. Please refer to Non-GAAP Financial Measures provided in the Appendix. (2) CC = constant currency. • Strong total company revenue, Adj EBITDA(1) growth, and margin expansion vs Q2 ‘24 • Sterigenics Q2 ’25 double-digit revenue growth vs Q2 ’24 • Nordion grew revenue approximately 3% vs Q2 ’24 • Nelson Labs 514 bps segment income margin improvement vs Q2 ‘24 Business & Market Update Q2 ‘25 vs Q2 ‘24 Financial Performance Capital Deployment & Liquidity Other Activities • Capital deployment priorities continue to be organic growth, leverage reduction and M&A opportunities • As of 6/30/25, strong liquidity of $918M and no outstanding borrowings on the revolving line of credit • Net Leverage Ratio(1) improved to 3.5x as of 6/30/25 vs 3.7x as of 12/31/24 • Sterigenics to add new X-ray sterilization capabilities in the Southeast US • Nelson Labs to double cleanroom capacity at Salt Lake City headquarters, to support growing demand for sterility assurance testing • Signed $34M binding term sheet on 7/23/25 to settle 129 EO claims in Illinois; expected to be finalized this winter Net Revenues 6.4%, 6.0% CC(1)(2) Adjusted EBITDA 9.8%, 9.5% CC Adjusted EBITDA margin(1) 156 bps to 51.2% Adjusted EPS(1) +$0.01 to $0.20

• 10. © 2025 Sotera Health Company | All Rights Reserved. Financials 9

• 11. © 2025 Sotera Health Company | All Rights Reserved. (1) Adjusted EBITDA margin is equal to Adjusted EBITDA divided by net revenues. Please refer to Non-GAAP Financial Measures provided in the Appendix. $137 $151 2024 2025 $249 $273 2024 2025 +9.8% / +9.5% CC +9.3% / +10.2% CC $0.19 $0.20 2024 2025 +$0.01 $0.32 $0.33 2024 2025 +$0.01 Revenue Adjusted EBITDA $ In millions, except Adjusted EPS and Adjusted EBITDA margin Q2 2025 Consolidated Financial Performance 10 Adjusted EPS Second Quarter 49.7%(1) 51.2%(1) Year-to-Date 47.5%(1) 49.7%(1) $277 $294 2024 2025 $525 $549 2024 2025 +6.4% / +6.0% CC +4.6% / +5.3% CC 10

• 12. © 2025 Sotera Health Company | All Rights Reserved. Sterigenics Financial Performance 11 $ In millions • Revenue growth for the quarter driven by favorable volume/mix, pricing, and changes in foreign currency exchange rates. • Segment income and segment income margin increased for the quarter driven by favorable volume/mix and pricing, partially offset by inflation. Second Quarter Year-to-Date $343 $365 $183 $196 2024 2025 Revenue Segment Income 53.7%(1) 53.3%(1) $176 $195 $97 $108 2024 2025 Revenue Segment Income 55.3%(1) 54.9%(1) Revenue +10.5% / +10.0% CC Segment Income +11.3% / +11.1% CC Revenue +6.3% / +7.1% CC Segment Income +7.2% / +8.2% CC (1) Segment income margin is equal to segment income divided by net segment revenues.

• 13. © 2025 Sotera Health Company | All Rights Reserved. Revenue +2.9% / +3.4% CC Segment Income +0.2% / +0.7% CC Nordion Financial Performance 12 $ In millions 54.9% • Revenue growth for the quarter driven by favorable pricing and volume/mix, partially offset by unfavorable changes in (2) foreign currency exchange rates. • Segment income margin decrease for the quarter attributed to supplier mix. Second Quarter Year-to-Date Revenue +14.9% / +16.8% CC Segment Income +19.6% / +21.0% CC $65 $75 $34 $41 2024 2025 Revenue Segment Income 54.5%(1) 52.4%(1) $41 $42 $23 $23 2024 2025 Revenue Segment Income 55.3%(1) 56.8%(1) (1) Segment income margin is equal to segment income divided by net segment revenues.

• 14. © 2025 Sotera Health Company | All Rights Reserved. Nelson Labs Financial Performance 13 $ In millions 54.9% • Improvement in core lab testing services, favorable pricing, and changes in foreign currency exchange rates were offset by a (2) decline in expert advisory services revenue. • Segment income and segment income margin increases driven by volume/mix improvements, lab optimization, and favorable pricing. Second Quarter Year-to-Date Revenue -3.3% / -4.4% CC Segment Income +13.9% / +12.1% CC Revenue -6.3% / -6.4% CC Segment Income +10.6% / +10.3% CC $117 $109 $32 $36 2024 2025 Revenue Segment Income 32.9%(1) 27.8%(1) $59 $57 $17 $20 2024 2025 Revenue Segment Income 34.2%(1) 29.0%(1) (1) Segment income margin is equal to segment income divided by net segment revenues.

• 15. © 2025 Sotera Health Company | All Rights Reserved. Net Leverage, Liquidity and Investments 14 $ In millions $77 $51 YTD 2024 YTD 2025 3.8x 3.7x 3.5x 12/31/23 12/31/24 6/30/25 (1) Excludes any Capital Expenditures included in accounts payable or accruals at the end of the applicable period. (2) Revolving Credit Facility availability is calculated as maximum facility size less letters of credit. Maximum facility size was $423.8M as of 12/31/24, increased to $600M as of April 30, 2025. Liquidity Position • As of 6/30/25 strong liquidity position of $918M and no outstanding borrowings on the revolving line of credit Target of 2.0x-3.0x by 2027 • Net Leverage Ratio improved to 3.5x as of 6/30/25 • Adjusted EBITDA growth and cash generation drove improvement in Net Leverage Ratio $296 $277 $332 $400 $410 $586 12/31/23 12/31/24 6/30/25 Unrestricted Cash and cash equivalents Revolver Availability $696 Liquidity Net Leverage Ratio Capital Expenditures(1) Target of ~$110M for FY 2027 • Sterigenics: 2 active capacity expansions; continued EO facility investments • Nordion: Cobalt-60 development projects • Nelson Labs: Pharma expansion & cleanroom expansion $687 $918 (2)

• 16. © 2025 Sotera Health Company | All Rights Reserved. 2025 Outlook 15 On the following slides, Sotera Health presents an overview of its full-year 2025 outlook, including certain non-GAAP financial measures. As outlined in the Company’s August 8, 2025 press release, Sotera Health does not provide a reconciliation of the forwardlooking Adjusted EBITDA, Tax Rate Applicable to Adjusted Net Income, Adjusted Net Income and Adjusted EPS to the most directly comparable GAAP measure, as this cannot be done without unreasonable effort due to the variability and low visibility with respect to certain costs, including, among others, uncertainties caused by changes to the regulatory landscape, restructuring items and certain fair value measurements, all of which are potential adjustments for future earnings. The variability of these forward-looking items could have a potentially unpredictable, and a potentially significant, impact on our future GAAP results.

• 17. © 2025 Sotera Health Company | All Rights Reserved. Full-year 2025 Outlook(1) 16 (1) The outlook provided on this slide contains a number of assumptions, including, among others, the Company’s current expectations regarding supply chain continuity, particularly for the supply of EO and Co-60, the impact of inflationary trends, including their impact on energy prices and the supply of labor. Our outlook is based on current plans and expectations and is subject to several known and unknown risks and uncertainties, including those set forth on the slide titled “Cautionary Note Regarding Forward-Looking Statements and Non-GAAP Financial Measures.” (2) Excludes the impact of translational currency. (3) Assumes average foreign exchange rates for second-quarter 2025 remain constant for the remainder of 2025. Prior Outlook August 8th Outlook Net Revenues(2) +4.0% to +6.0% +4.5% to +6.0% Net Revenues Currency Impact(3) ~(1.25%) Neutral Adj EBITDA(2) +4.5% to +6.5% +6.0% to +7.5% Adj EBITDA Currency Impact(3) ~(1.50%) Neutral Adj EPS(2) $0.70 to $0.76 $0.75 to $0.82

• 18. © 2025 Sotera Health Company | All Rights Reserved. Full-year 2025 Outlook(1)– Additional Items 17 (1) The outlook provided on this slide contains a number of assumptions, including, among others, the Company’s current expectations regarding supply chain continuity, particularly for the supply of EO and Co-60, the impact of inflationary trends, including their impact on energy prices and the supply of labor. Our outlook is based on current plans and expectations and is subject to several known and unknown risks and uncertainties, including those set forth on the slide titled “Cautionary Note Regarding Forward-Looking Statements and Non-GAAP Financial Measures.” (2) This is a non-GAAP financial measure. Please refer to Non-GAAP Financial Measures provided in the Appendix. Prior Outlook August 8th Outlook Interest Expense $155M to $165M $155M to $165M Tax Rate Applicable to Adj Net Income(2) 33% to 35% 31.5% to 33.5% Weighted Average Diluted Shares 286M to 287M 286M to 287M Capital Expenditures $190M to $210M $170M to $180M

• 19. © 2025 Sotera Health Company | All Rights Reserved. Other 2025 Outlook Items 18 • Raised revenue outlook to 4.5% - 6.0%; raised Adjusted EBITDA outlook to 6.0% - 7.5%, both on a constant currency basis • No FX impact expected on FY ‘25 revenue and Adjusted EBITDA, based on average second-quarter ‘25 exchange rates • Total company price expected to be approximately at the mid-point of the 3% - 4% long-term range • Outlook assumes no M&A activity General Commentary • Sterigenics constant currency revenue growth in the mid-single to high-single digits for FY ‘25 • Nordion constant currency revenue growth in the mid-single digits for FY ’25 • Nordion Q4 2025 revenues expected to be down mid-teens versus Q4 2024 • Nelson Labs constant currency revenue down low-single digits for FY ‘25, with a return to growth in Q4 ‘25 • FY ’25 segment income margin improvement Cadence • Capital deployment priorities continue to be organic growth, leverage reduction and opportunistic M&A • Reduced capital expenditures range to $170M - $180M • Net Leverage Ratio expected to improve compared to year-end ‘24 Capital Deployment & Net Leverage

• 20. © 2025 Sotera Health Company | All Rights Reserved. Our Company Key Priorities 19 Excellence in serving our customers with end-to-end solutions Win in growth markets Driving operational excellence to enhance free cash flow Disciplined capital deployment 1 2 3 4 Strong Execution to Generate Value for Our Stakeholders

• 21. © 2025 Sotera Health Company | All Rights Reserved. Appendix 20

• 22. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures 21 (unaudited) (dollars in thousands, except per share amounts) Three Months Ended June 30, Six Months Ended June 30, 2025 2024 2025 2024 Segment revenues: Sterigenics $ 194,839 $ 176,354 $ 364,523 $ 342,851 Nordion 42,431 41,244 74,988 65,251 Nelson Labs 57,071 58,996 109,353 116,668 Total net revenues $ 294,341 $ 276,594 $ 548,864 $ 524,770 Segment income: Sterigenics $ 107,745 $ 96,778 $ 195,749 $ 182,596 Nordion 23,477 23,420 40,899 34,205 Nelson Labs 19,513 17,137 35,926 32,478 Total segment income 150,735 137,335 272,574 249,279 Less adjustments: Interest expense, net $ 40,651 $ 40,388 $ 81,527 $ 82,159 Depreciation and amortization(a) 34,948 39,830 75,682 80,260 Share-based compensation(b) 8,149 10,206 15,418 18,863 Loss on refinancing of debt(c) 80 23,400 80 24,090 (Gain) Loss on foreign currency and derivatives not designated as hedging instruments, net(d) (3,018) (698) (1,127) 532 Business optimization expenses(e) 2,430 613 4,477 1,784 Professional services relating to EO sterilization facilities(f) 14,035 7,818 26,363 14,157 Illinois EO litigation settlements(g) 34,000 — 64,943 — Accretion of asset retirement obligation(h) 563 636 1,137 1,278 Consolidated income before income taxes $ 18,897 $ 15,142 $ 4,074 $ 26,156

• 23. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures (continued) 22 a) Includes depreciation of Co-60 held at gamma irradiation sites. The three and six months ended June 30, 2025 exclude accelerated depreciation associated with business optimization activities. b) Represents share-based compensation expense related to employees and Non-Employee Directors. c) Represents the write-off of unamortized debt issuance costs and discounts, as well as certain other costs incurred related to the Refinancing Term Loans, the Secured Notes and the Revolving Credit Facility. d) 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. e) Represents (i) certain costs related to divestitures, acquisitions and the integration of acquisitions, (ii) professional fees and other costs associated with business optimization, cost saving and other process enhancement projects, and (iii) legal, consulting and other fees associated with the secondary offerings and shareholder engagement. f) Represents litigation and other professional fees associated with our EO sterilization facilities. g) Represents (i) the cost to settle 97 pending and threatened EO claims against Sterigenics in Illinois pursuant to the term sheet entered into on April 3, 2025 and (ii) the cost to settle 129 pending and threatened EO claims against Sterigenics in Illinois pursuant to the term sheet entered into on July 23, 2025. h) Represents non-cash accretion of ARO related to Co-60 gamma and EO sterilization 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.

• 24. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures 23 (unaudited) (dollars in thousands, except per share amounts) Three Months Ended June 30, Six Months Ended June 30, 2025 2024 2025 2024 Net income (loss) $ 7,962 $ 8,754 $ (5,298) $ 15,077 Amortization of intangible assets 11,924 19,755 30,598 39,879 Share-based compensation(a) 8,149 10,206 15,418 18,863 Loss on refinancing of debt(b) 80 23,400 80 24,090 (Gain) Loss on foreign currency and derivatives not designated as hedging instruments, net(c) (3,018) (698) (1,127) 532 Business optimization expenses(d) 2,430 613 4,477 1,784 Professional services relating to EO sterilization facilities(e) 14,035 7,818 26,363 14,157 Illinois EO litigation settlements(f) 34,000 — 64,943 — Accretion of asset retirement obligation(g) 563 636 1,137 1,278 Income tax benefit associated with pre-tax adjustments(h) (20,063) (15,297) (41,485) (24,844) Adjusted Net Income 56,062 55,187 95,106 90,816 Interest expense, net 40,651 40,388 81,527 82,159 Depreciation(i) 23,024 20,075 45,084 40,381 Income tax provision applicable to Adjusted Net Income(j) 30,998 21,685 50,857 35,923 Adjusted EBITDA(k) $ 150,735 $ 137,335 $ 272,574 $ 249,279 Net Revenues $ 294,341 $ 276,594 $ 548,864 $ 524,770 Adjusted EBITDA Margin 51.2 % 49.7 % 49.7 % 47.5 % Weighted average number of shares outstanding Basic 283,933 282,894 283,747 282,403 Diluted(l) 285,756 284,541 285,684 284,264 Earnings (Loss) per share Basic $ 0.03 $ 0.03 $ (0.02) $ 0.05 Diluted 0.03 0.03 (0.02) 0.05 Adjusted earnings per share Basic $ 0.20 $ 0.20 $ 0.34 $ 0.32 Diluted 0.20 0.19 0.33 0.32

• 25. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures (continued) 24 a) Represents share-based compensation expense related to employees and Non-Employee Directors. b) Represents the write-off of unamortized debt issuance costs and discounts, as well as certain other costs incurred related to the Refinancing Term Loans, the Secured Notes and the Revolving Credit Facility. c) 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. d) Represents (i) certain costs related to divestitures, acquisitions and the integration of acquisitions, (ii) professional fees and other costs associated with business optimization, cost saving and other process enhancement projects, and (iii) legal, consulting and other fees associated with the secondary offerings and shareholder engagement. e) Represents litigation and other professional fees associated with our EO sterilization facilities. f) Represents (i) the cost to settle 97 pending and threatened EO claims against Sterigenics in Illinois pursuant to the term sheet entered into on April 3, 2025 and (ii) the cost to settle 129 pending and threatened EO claims against Sterigenics in Illinois pursuant to the term sheet entered into on July 23, 2025. g) Represents non-cash accretion of ARO related to Co-60 gamma and EO sterilization 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. h) Represents the income tax impact of adjustments calculated based on the tax rate applicable to each item. We eliminate the effect of tax rate changes as applied to tax assets and liabilities and unusual items from our presentation of adjusted net income. i) Includes depreciation of Co-60 held at gamma irradiation sites. The three and six months ended June 30, 2025 excludes accelerated depreciation associated with business optimization activities. j) Represents the difference between the income tax provision or benefit as determined under U.S. GAAP and the income tax provision or benefit associated with pre-tax adjustments described in footnote (h). k) $24.4 million and $23.4 million of the adjustments for the three months ended June 30, 2025 and 2024, respectively, and $48.6 million and $47.2 million of the adjustments for the six months ended June 30, 2025 and 2024, respectively, are included in cost of revenues, primarily consisting of amortization of intangible assets, depreciation, and accretion of asset retirement obligations. l) For the six months ended June 30, 2025, the diluted weighted average shares outstanding presented in this table reflects the amount that would be reported under U.S. GAAP if the Company were to have net income in the six months ended June 30, 2025.

• 26. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures 25 (unaudited) (dollars in thousands, except per share amounts) Year Ended December 31, Twelve Months Ended June 30, 2023 2024 2025 Net income $ 51,376 $ 44,398 $ 24,023 Amortization of intangible assets 81,348 79,377 70,096 Share-based compensation(a) 32,364 36,896 33,451 Loss on refinancing of debt(b) — 24,168 158 (Gain) loss on foreign currency and derivatives not designated as hedging instruments, net(c) (1,552) 2,448 789 Business optimization expenses(d) 7,662 9,368 12,061 Professional services and other expenses relating to EO sterilization facilities(e) 45,312 32,694 44,900 Illinois EO litigation settlement(f) — — 64,943 Georgia EO litigation settlement(g) 35,000 — — Accretion of asset retirement obligations(h) 2,413 2,638 2,497 Income tax benefit associated with pre-tax adjustments(i) (49,597) (33,487) (50,128) Adjusted Net Income 204,326 198,500 202,790 Interest expense, net 142,878 164,691 164,059 Depreciation(j) 76,577 82,420 87,123 Income tax provision applicable to Adjusted Net Income(k) 104,248 102,963 117,897 Adjusted EBITDA(l) $ 528,029 $ 548,574 $ 571,869

• 27. © 2025 Sotera Health Company | All Rights Reserved. a) Represents share-based compensation expense related to employees and Non-Employee Directors. b) Represents the write-off of unamortized debt issuance costs and discounts, as well as certain other costs incurred related to the Refinancing Term Loans, the Secured Notes and the Revolving Credit Facility. c) 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. d) Represents (i) certain costs related to divestitures, acquisitions and the integration of acquisitions, (ii) professional fees and other costs associated with business optimization, cost saving and other process enhancement projects, and (iii) legal, consulting and other fees associated with the secondary offerings and shareholder engagement. The year ended December 31, 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. e) Represents litigation and other professional fees associated with our EO sterilization facilities. f) Represents (i) the cost to settle 97 pending and threatened EO claims against Sterigenics in Illinois pursuant to the term sheet entered into on April 3, 2025, and (ii) the cost to settle 129 pending and threatened EO claims against Sterigenics in Illinois pursuant to the term sheet entered into on July 23, 2025. g) Represents the cost to settle 79 pending EO claims in Georgia under a settlement term sheet entered into on December 21, 2023. h) Represents non-cash accretion of asset retirement obligations related to Co-60 gamma and EO processing facilities, which are based on estimated site remediation costs for any future decommissioning of these facilities and are accreted over the life of the asset. i) Represents the income tax impact of adjustments calculated based on the tax rate applicable to each item. We eliminate the effect of tax rate changes as applied to tax assets and liabilities, and unusual items from our presentation of adjusted net income. j) Includes depreciation of Co-60 held at gamma irradiation sites. The year ended December 31, 2024 and twelve months ended June 30, 2025 exclude accelerated depreciation associated with business optimization activities. k) Represents the difference between the income tax provision/benefit as determined under U.S. GAAP and the income tax benefit associated with pre-tax adjustments described in footnote (i). l) $94.1 million and $97.1 million of the adjustments for the years ended December 31, 2023 and 2024, respectively, and $98.5 million of the adjustments for the twelve months ended June 30, 2025 are included in cost of revenues, primarily consisting of amortization of intangible assets, depreciation, and accretion of asset retirement obligations. Non-GAAP Financial Measures (continued) 26

• 28. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures (continued) 27 (a) Represents Adjusted EBITDA for the years ended December 31, 2023, December 31, 2024 and the twelve months ended June 30, 2025, respectively. Refer to the reconciliations of Adjusted EBITDA to net income (loss) for additional detail. As of December 31, As of June 30, 2023 2024 2025 Current portion of long-term debt $ 4,797 14,803 14,820 Long-term debt less current portion 2,223,674 2,208,100 2,202,651 Current portion of finance leases 8,771 2,923 3,237 Finance leases less current portion 63,793 95,286 95,420 Total Debt 2,301,035 2,321,112 2,316,128 Less: cash and cash equivalents (296,407) (277,242) (332,437) Total Net Debt $ 2,004,628 $ 2,043,870 $ 1,983,691 Adjusted EBITDA(a) $ 528,029 $ 548,574 $ 571,869 Net Leverage 3.8x 3.7x 3.5x

• 29. © 2025 Sotera Health Company | All Rights Reserved. Non-GAAP Financial Measures Definitions 28 • Adjusted Net Income is defined as net income (loss) before amortization and certain other adjustments that we do not consider in our evaluation of our ongoing operating performance from period to period. • Adjusted EBITDA is defined as Adjusted Net Income before interest expense, depreciation (including depreciation of Co-60 used in our operations) and income tax provision applicable to Adjusted Net Income. • Adjusted EBITDA margin is equal to Adjusted EBITDA divided by net revenues. • Adjusted EPS is defined as Adjusted Net Income divided by the weighted average number of diluted shares outstanding. • Net Debt is equal to our total debt net of unamortized debt issuance costs and debt discounts, less cash and cash equivalents. • Net Leverage Ratio is equal to Net Debt divided by Adjusted EBITDA. • Segment income margin is equal to segment income divided by net segment revenues. • We calculate constant currency (CC) net revenues by translating prior year net revenues in local currency at the average exchange rates applicable for the current period. The translated results are then used to determine year-over-year percentage increases or decreases. We generally refer to such amounts calculated on a constant currency basis as excluding the impact of foreign currency exchange rates.