Sec Form 4 Filing - Lyons Jonathan M. @ Sotera Health Co - 2025-03-02

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Lyons Jonathan M. 2. Issuer Name and Ticker or Trading Symbol Sotera Health Co [ SHC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Sr. Vice President, CFO (Last) (First) (Middle) 9100 SOUTH HILLS BLVD, SUITE 300 3. Date of Earliest Transaction (MM/DD/YY) 03/02/2025 (Street) BROADVIEW HEIGHTS, OH44147 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, $0.01 par value per share ("Common Stock") 03/02/2025 F 6,481 ( 1 ) D $ 12.47 103,951 D Common Stock 03/03/2025 A 59,790 ( 2 ) A $ 0 163,741 D Common Stock 03/03/2025 A 37,369 ( 3 ) A $ 0 201,110 ( 4 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Performance RSUs ( 5 ) 03/03/2025 A 29,895 ( 5 ) ( 5 ) ( 5 ) Common Stock 29,895 $ 0 29,895 D Stock Options ( 6 ) $ 14.59 ( 7 ) 03/04/2034 Common Stock 81,676 81,676 D Stock Options ( 6 ) $ 16.89 ( 8 ) 08/07/2033 Common Stock 33,640 33,640 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Lyons Jonathan M. 9100 SOUTH HILLS BLVD, SUITE 300 BROADVIEW HEIGHTS, OH44147 Sr. Vice President, CFO Signatures Gregory S. Harvey, Attorney-in-Fact 03/04/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These securities represent the number of shares of Common Stock withheld by the Issuer to satisfy the Reporting Person's tax withholding obligations due upon the vesting of 13,708 Restricted Stock Units ("RSUs"), which represents 33% of the RSU award granted to the Reporting Person on March 4, 2024. This award was granted pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incentive Plan ("2020 Incentive Plan"). Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. ( 2 )These securities consist of RSUs that were granted on March 3, 2025, pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs generally vest annually in 60%, 20%, and 20% installments, respectively, commencing March 3, 2026. ( 3 )These securities consist of RSUs that were granted on March 3, 2025, pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting condictions. The RSUs vest in two equal installments on each of March 3, 2026 and March 3, 2027, subject to the Reporting Person's continued service through each such date. ( 4 )These securities consist of 175,887 RSUs and 25,223 shares of Common Stock. ( 5 )These securities consist of a maximum number of additional performance-based RSUs that were granted on March 3, 2025, pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each additional RSU represents the Reporting Person's right to receive one share of Common Stock, subject to stock price-related performance conditions. The additional RSUs generally vest annually in 60%, 20%, and 20% installments, respectively, commencing March 3, 2026, subject to performance. ( 6 )No transaction is being reported on this line. Reported on a previously filed Form 4. ( 7 )These options were granted on March 4, 2024, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest annually in three equal installments commencing on March 2, 2025, subject to the Reporting Person's continued service through each such date. ( 8 )These options were granted on August 7, 2023, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest annually in three equal installments commencing August 5, 2024, subject to the Reporting Person's continued service through each such date.

Remarks: The Power of Attorney for Mr. Lyons is filed as an exhibit to the Form 3 filed on July 6, 2023, which is hereby incorporated by reference.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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