Sec Form 3 Filing - Klaben Matthew J @ Sotera Health Co - 2022-10-01

FORM 3 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 Klaben Matthew J 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) Interim SVP, GC and Secretary (Last) (First) (Middle) C/O SOTERA HEALTH COMPANY, 9100 SOUTH HILLS BDVD, SUITE 300 3. Date of Earliest Transaction (MM/DD/YY) 10/01/2022 (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") 37,703( 1 ) D Common Stock 314,286( 2 ) I By grantor trust

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 Stock Options $ 23 ( 3 ) 11/20/2030 Common Stock 134,161( 3 ) D Stock Options $ 20.03 ( 4 ) 03/02/2032 Common Stock 22,350( 4 ) D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Klaben Matthew J C/O SOTERA HEALTH COMPANY 9100 SOUTH HILLS BDVD, SUITE 300 BROADVIEW HEIGHTS, OH44147 Interim SVP, GC and Secretary Signatures /s/ Jessica L.M.H. Epp, Attorney-in-Fact 10/07/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These securities consist of 5,489 shares of Common Stock and 32,214 Restricted Stock Units ("RSUs"). 23,478 RSUs were granted on November 20, 2020, and the balance of these RSUs will vest in three equal annual installments beginning on November 20, 2022, subject to the Reporting Person's continued service through each such date. 8,736 RSUs were granted on March 2, 2022, and will vest in three equal annual installments on each of the first three anniversaries of the date of grant, subject to the Reporting Person's continued service through each such date. The RSUs were granted pursuant to the terms of RSU agreements 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 )Consists of 220,526 shares of vested Common Stock and 93,760 shares of unvested Common Stock. 93,760 of the unvested shares of Common Stock will vest as of the first date on which (i) certain investment funds and entities affiliated with Warburg Pincus LLC and GTCR, LLC (the "Sponsors") have received two and one-half times their invested capital in the company and (ii) the Sponsors' internal rate of return exceeds twenty percent. ( 3 )These options were granted on November 20, 2020, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest in four equal installments on each of the first four anniversaries of the date of grant, subject to the Reporting Person's continued service through each such date. ( 4 )These options were granted on March 2, 2022, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest in three equal installments on each of the first three anniversaries of the date of grant, subject to the Reporting Person's continued service through each such date.

Remarks: Exhibit 24.1 - Power of Attorney

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