SHC

SEC source: 0001193125-26-356962 · ownership.xml · nonDerivative · entry 2

Petras Michael B. Jr. · CIK 0001832387 · Director · Executive Chairman

10b5-1 filing: No plan indicated

Ownership: Indirect · By Grantor Trust

Disclosed balance after: 3,969,393

F2 · price: Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $18.50 - $18.855. The reporting person hereby undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price.

SEC source: 0001193125-26-356962 · ownership.xml · nonDerivative · entry 1

Petras Michael B. Jr. · CIK 0001832387 · Director · Executive Chairman

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 397,912

F1 · price: Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $18.50 - $18.855. The reporting person hereby undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price.

SEC source: 0001193125-26-344757 · ownership.xml · nonDerivative · entry 1

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 334,279

F1 · price: Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $18.75 - $18.9050. The reporting person hereby undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price.

SEC source: 0001193125-26-340288 · ownership.xml · nonDerivative · entry 1

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 217,304

F1 · shares: 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 25,657 Restricted Stock Units ("RSUs"), which represents 33% of the RSU awards granted to the Reporting Person on August 7, 2023. These awards 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.

SEC source: 0001193125-26-242277 · ownership.xml · derivative · entry 3

SHADER ALTON · CIK 0001523442 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 101,817

Underlying: Common Stock · 101,817 shares

Expires not disclosed

F3 · derivative.exercise_price: These securities consist of a maximum number of performance-based share appreciation units ("SAUs") that were granted on May 26, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock subject to stock-price-related performance conditions. The SAUs generally vest annually over three years in equal installments, commencing March 2, 2027, subject to performance.

F3 · shares: These securities consist of a maximum number of performance-based share appreciation units ("SAUs") that were granted on May 26, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock subject to stock-price-related performance conditions. The SAUs generally vest annually over three years in equal installments, commencing March 2, 2027, subject to performance.

F3 · derivative.exercise_date: These securities consist of a maximum number of performance-based share appreciation units ("SAUs") that were granted on May 26, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock subject to stock-price-related performance conditions. The SAUs generally vest annually over three years in equal installments, commencing March 2, 2027, subject to performance.

F3 · derivative.expiration_date: These securities consist of a maximum number of performance-based share appreciation units ("SAUs") that were granted on May 26, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock subject to stock-price-related performance conditions. The SAUs generally vest annually over three years in equal installments, commencing March 2, 2027, subject to performance.

SEC source: 0001193125-26-242277 · ownership.xml · nonDerivative · entry 2

SHADER ALTON · CIK 0001523442 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 579,573

F2 · shares: These securities consist of RSUs that were granted on May 26, 2026, 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 over three years in equal increments, commencing March 2, 2027.

SEC source: 0001193125-26-242277 · ownership.xml · nonDerivative · entry 1

SHADER ALTON · CIK 0001523442 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 375,939

F1 · shares: These securities consist of RSUs that were granted on May 26, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Incentive Plan ("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 over three years in equal increments, commencing March 2, 2027.

SEC source: 0001193125-26-242181 · ownership.xml · nonDerivative · entry 1

Simon, Christopher · CIK 0001674993 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 34,102

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 19,132 shares of Common Stock.

SEC source: 0001193125-26-242192 · ownership.xml · nonDerivative · entry 1

PETRELLA VINCENT K · CIK 0001276410 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 95,751

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 80,961 shares of Common Stock.

SEC source: 0001193125-26-242197 · ownership.xml · nonDerivative · entry 1

Neary James · CIK 0001323057 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 95,751

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 80,961 shares of Common Stock.

SEC source: 0001193125-26-242246 · ownership.xml · nonDerivative · entry 1

Kyle Richard G · CIK 0001507947 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,970

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

SEC source: 0001193125-26-242231 · ownership.xml · nonDerivative · entry 1

Flynn Karen · CIK 0001553599 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 54,191

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 39,221 shares of Common Stock.

SEC source: 0001193125-26-242243 · ownership.xml · nonDerivative · entry 1

Krause Kenneth D. · CIK 0001661311 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,970

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

SEC source: 0001193125-26-242188 · ownership.xml · nonDerivative · entry 1

Chen Ruoxi · CIK 0001769832 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 95,751

F1 · shares: These securities consist of 14,970 Restricted Stock Units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incentive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 80,961 shares of Common Stock.

SEC source: 0001193125-26-242177 · ownership.xml · nonDerivative · entry 1

Wheadon David E. · CIK 0001789507 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 89,882

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 74,912 shares of Common Stock.

SEC source: 0001193125-26-242452 · ownership.xml · nonDerivative · entry 1

Klee Ann R. · CIK 0001796076 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 140,926

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: Consist of 14,970 RSUs and 125,956 shares of Common Stock.

SEC source: 0001193125-26-242237 · ownership.xml · nonDerivative · entry 1

CUNNINGHAM SEAN LAURENCE · CIK 0001829753 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 95,751

F1 · shares: These securities consist of 14,970 restricted stock units ("RSUs") that were granted on May 22, 2026, pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Omnibus Incenctive Plan. Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions. The RSUs will vest in full on the earlier of (i) the first anniversary of the date of grant, or (ii) the date immediately prior to the Issuer's next regular annual shareholders meeting, subject to the Reporting Person's continued service as a non-employee director of the Issuer through such date.

F2 · balance_after: These securities consist of 14,970 RSUs and 80,781 shares of Common Stock.

SEC source: 0001999371-26-010899 · ownership.xml · nonDerivative · entry 1

WARBURG PINCUS & CO. · CIK 0000929408 · Director · 10% owner

Bull Co-Invest L.P. · CIK 0001832693 · Director · 10% owner

Warburg Pincus Private Equity XI, L.P. · CIK 0001540163 · Director · 10% owner

Bull Holdco L.P. · CIK 0002014247 · Director · 10% owner

Warburg Pincus Partners II, L.P. · CIK 0001658787 · Director · 10% owner

Warburg Pincus Private Equity XI-B, L.P. · CIK 0001540166 · Director · 10% owner

Warburg Pincus XI Partners, L.P. · CIK 0001540386 · Director · 10% owner

Warburg Pincus XI, L.P. · CIK 0001540167 · Director · 10% owner

WP Global LLC · CIK 0001540385 · Director · 10% owner

WP XI Partners, L.P. · CIK 0001540164 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F1 · shares: On May 13, 2026, certain of the Warburg Pincus Entities (as defined below) sold a total of 19,102,952 shares of Common Stock of Sotera Health Company (the "Issuer") in an underwritten public secondary offering (the "Offering").

F2 · ownership.nature: Warburg Pincus XI, L.P., a Delaware limited partnership ("WP XI GP"), is the general partner of each of (i) Warburg Pincus Private Equity XI, L.P. ("WP XI"), (ii) Warburg Pincus Private Equity XI-B, L.P. ("WP XI-B"), (iii) WP XI Partners, L.P. ("WP XI Partners") and (iv) Warburg Pincus XI Partners, L.P. ("Warburg Pincus XI Partners"). WP Global LLC ("WP Global"), is the general partner of WP XI GP. Warburg Pincus Partners II, L.P. ("WPP II"), is the managing member of WP Global. Warburg Pincus Partners GP LLC ("WPP GP LLC"), is the general partner of WPP II. Warburg Pincus & Co. ("WP"), is the managing member of WPP GP LLC. Warburg Pincus (Cayman) XI, L.P. ("WP XI Cayman GP"), is the general partner of Warburg Pincus Private Equity XI-C, L.P. ("WP XI-C" and, together with WP XI, WP XI-B, WP XI Partners and Warburg Pincus XI Partners, the "WP XI Funds").

F3 · ownership.nature: The WP XI Funds, Bull Co-Invest L.P. ("Bull Co-Invest"), Bull Holdco L.P. ("Bull Holdco"), WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are collectively referred to herein as the "Warburg Pincus Entities.

F4 · ownership.nature: Each Warburg Pincus Entity disclaims beneficial ownership with respect to any shares of Common Stock of the Issuer, except to the extent of its pecuniary interest in such shares of Common Stock, if any. The WP XI Funds, Bull Co-Invest, Bull Holdco, WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are directors-by-deputization solely for purposes of Section 16 of the Securities Exchange Act of 1934, as amended. Information with respect to each of the Warburg Pincus Entities is given solely by such Warburg Pincus Entity, and no Warburg Pincus Entity has responsibility for the accuracy or completeness of information supplied by another Warburg Pincus Entity.

F5 · ownership.nature: Warburg Pincus XI-C, LLC ("WP XI-C LLC"), is the general partner of WP XI Cayman GP. Warburg Pincus Partners II (Cayman), L.P. ("WPP II Cayman"), is the managing member of WP XI-C LLC. Warburg Pincus (Bermuda) Private Equity GP Ltd. ("WP Bermuda GP"), is the general partner of WPP II Cayman. WP Bull Manager LLC ("WP Bull Manager"), is the general partner of Bull Co-Invest. WP is managing member of WP Bull Manager. Warburg Pincus LLC, a New York limited liability company ("WP LLC"), is the manager of the WP XI Funds. The WP XI Funds share limited partnership ownership in Bull Holdco on a pro rata basis in accordance with their respective numbers of Contributed Shares.

SEC source: 0001999371-26-010903 · ownership.xml · nonDerivative · entry 1

WARBURG PINCUS & CO. · CIK 0000929408 · Director · 10% owner

Warburg Pincus (Bermuda) Private Equity GP Ltd. · CIK 0001555729 · Director · 10% owner

Warburg Pincus (Cayman) XI, L.P. · CIK 0001554853 · Director · 10% owner

WARBURG PINCUS LLC · CIK 0001162870 · Director · 10% owner

Warburg Pincus Partners GP LLC · CIK 0001621224 · Director · 10% owner

Warburg Pincus Partners II (Cayman), L.P. · CIK 0001658820 · Director · 10% owner

Warburg Pincus Private Equity XI-C, L.P. · CIK 0001550877 · Director · 10% owner

Warburg Pincus XI-C, LLC · CIK 0001554852 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F1 · shares: On May 13, 2026, certain of the Warburg Pincus Entities (as defined below) sold a total of 19,102,952 shares of Common Stock of Sotera Health Company (the "Issuer") in an underwritten public secondary offering (the "Offering").

F2 · ownership.nature: Warburg Pincus XI, L.P., a Delaware limited partnership ("WP XI GP"), is the general partner of each of (i) Warburg Pincus Private Equity XI, L.P. ("WP XI"), (ii) Warburg Pincus Private Equity XI-B, L.P. ("WP XI-B"), (iii) WP XI Partners, L.P. ("WP XI Partners") and (iv) Warburg Pincus XI Partners, L.P. ("Warburg Pincus XI Partners"). WP Global LLC ("WP Global"), is the general partner of WP XI GP. Warburg Pincus Partners II, L.P. ("WPP II"), is the managing member of WP Global.Warburg Pincus Partners GP LLC ("WPP GP LLC"), is the general partner of WPP II. Warburg Pincus & Co. ("WP"), is the managing member of WPP GP LLC.Warburg Pincus (Cayman) XI, L.P. ("WP XI Cayman GP"), is the general partner of Warburg Pincus Private Equity XI-C, L.P. ("WP XI-C" and, together with WP XI,WP XI-B, WP XI Partners and Warburg Pincus XI Partners, the "WP XI Funds").

F3 · ownership.nature: The WP XI Funds, Bull Co-Invest L.P. ("Bull Co-Invest"), Bull Holdco L.P. ("Bull Holdco"), WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are collectively referred to herein as the "Warburg Pincus Entities."

F4 · ownership.nature: Each Warburg Pincus Entity disclaims beneficial ownership with respect to any shares of Common Stock of the Issuer, except to the extent of its pecuniary interest in such shares of Common Stock, if any. The WP XI Funds, Bull Co-Invest, Bull Holdco, WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are directors-by-deputization solely for purposes of Section 16 of the Securities Exchange Act of 1934, as amended. Information with respect to each of the Warburg Pincus Entities is given solely by such Warburg Pincus Entity, and no Warburg Pincus Entity has responsibility for the accuracy or completeness of information supplied by another Warburg Pincus Entity.

F5 · ownership.nature: Warburg Pincus XI-C, LLC ("WP XI-C LLC"), is the general partner of WP XI Cayman GP. Warburg Pincus Partners II (Cayman), L.P. ("WPP II Cayman"), is the managing member of WP XI-C LLC. Warburg Pincus (Bermuda) Private Equity GP Ltd. ("WP Bermuda GP"), is the general partner of WPP II Cayman. WP Bull Manager LLC ("WP Bull Manager"), is the general partner of Bull Co-Invest. WP is managing member of WP Bull Manager. Warburg Pincus LLC, a New York limited liability company ("WP LLC"), is the manager of the WP XI Funds. The WP XI Funds share limited partnership ownership in Bull Holdco on a pro rata basis in accordance with their respective numbers of Contributed Shares.

SEC source: 0001193125-26-227029 · ownership.xml · nonDerivative · entry 1

GTCR INVESTMENT XI LLC · CIK 0001827977 · Director · 10% owner

GTCR FUND XI/A LP · CIK 0001591434 · Director · 10% owner

GTCR FUND XI/C LP · CIK 0001591436 · Director · 10% owner

GTCR CO-INVEST XI LP · CIK 0001591432 · Director · 10% owner

GTCR PARTNERS XI/A&C LP · CIK 0001828028 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 0

F1 · shares: On May 13, 2026, GTCR Fund XI/A LP, a Delaware limited partnership ("Fund XI/A"), GTCR Fund XI/C LP, a Delaware limited partnership ("Fund XI/C"), and GTCR Co-Invest XI LP, a Delaware limited partnership ("Co-Invest XI", and together with Fund XI/A and Fund XI/C, the "GTCR XI Funds"), sold a total of 12,735,301 shares of Common Stock of Sotera Health Company in an underwritten public secondary offering.

F2 · ownership.nature: GTCR Partners XI/A&C LP ("Partners XI/A&C") is the general partner of each of Fund XI/A and Fund XI/C. GTCR Investment XI LLC ("Investment XI" and together with the GTCR XI Funds and Partners XI/A&C, the "GTCR Entities"), is the general partner of Co-Invest XI and Partners XI/A&C. Investment XI is managed by a board of managers (the "GTCR Board of Managers") consisting of Mark M. Anderson, Aaron D. Cohen, Sean L. Cunningham, David A Donnini, Constantine S. Mihas and Collin E. Roche, and no single person has voting or dispositive authority over the shares of Common Stock.

F3 · ownership.nature: Each of Partners XI/A&C, Investment XI and the GTCR Board of Managers may be deemed to share beneficial ownership of the shares of Common Stock held of record by the GTCR XI Funds, and each of the individual members of the GTCR Board of Managers disclaims beneficial ownership of the shares of Common Stock held of record by the GTCR XI Funds except to the extent of his pecuniary interest therein.

F4 · ownership.nature: Each of the reporting persons is a director-by-deputization solely for purposes of Section 16 of the Exchange Act. Information with respect to each of the GTCR Entities is given solely by such GTCR Entity, and no GTCR Entity has responsibility for the accuracy or completeness of information supplied by another GTCR Entity.

SEC source: 0001193125-26-140422 · ownership.xml · nonDerivative · entry 1

DIMITRIEF ALEXANDER · CIK 0001614732 · Former SVP, GC and Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 312,040

F1 · shares: 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 17,135 Restricted Stock Units ("RSUs") 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"). The 17,135 RSUs under this award vested pursuant to the terms of the RSU agreement upon the Reporting Person's retirement on March 31, 2026.

SEC source: 0001999371-26-005532 · ownership.xml · nonDerivative · entry 1

WARBURG PINCUS & CO. · CIK 0000929408 · Director · 10% owner

Bull Co-Invest L.P. · CIK 0001832693 · Director · 10% owner

Warburg Pincus Private Equity XI, L.P. · CIK 0001540163 · Director · 10% owner

Bull Holdco L.P. · CIK 0002014247 · Director · 10% owner

Warburg Pincus Partners II, L.P. · CIK 0001658787 · Director · 10% owner

Warburg Pincus Private Equity XI-B, L.P. · CIK 0001540166 · Director · 10% owner

Warburg Pincus XI Partners, L.P. · CIK 0001540386 · Director · 10% owner

Warburg Pincus XI, L.P. · CIK 0001540167 · Director · 10% owner

WP Global LLC · CIK 0001540385 · Director · 10% owner

WP XI Partners, L.P. · CIK 0001540164 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 19,102,952

F1 · shares: On March 6, 2026, certain of the Warburg Pincus Entities (as defined below) sold a total of 15,000,000 shares of Common Stock of Sotera Health Company (the "Issuer") in an underwritten public secondary offering (the "Offering").

F2 · balance_after: Following the Offering, consists of (i) 15,287,717 shares of Common Stock of the Issuer held by Bull Holdco L.P. ("Bull Holdco") and (ii) 3,815,235 shares of Common Stock of the Issuer held by Bull Co-Invest L.P., a Delaware limited partnership ("Bull Co-Invest").

F3 · ownership.nature: Warburg Pincus XI, L.P., a Delaware limited partnership ("WP XI GP"), is the general partner of each of (i) Warburg Pincus Private Equity XI, L.P. ("WP XI"), (ii) Warburg Pincus Private Equity XI-B, L.P. ("WP XI-B"), (iii) WP XI Partners, L.P. ("WP XI Partners") and (iv) Warburg Pincus XI Partners, L.P. ("Warburg Pincus XI Partners"). WP Global LLC ("WP Global"), is the general partner of WP XI GP. Warburg Pincus Partners II, L.P. ("WPP II"), is the managing member of WP Global. Warburg Pincus Partners GP LLC ("WPP GP LLC"), is the general partner of WPP II. Warburg Pincus & Co. ("WP"), is the managing member of WPP GP LLC. Warburg Pincus (Cayman) XI, L.P. ("WP XI Cayman GP"), is the general partner of Warburg Pincus Private Equity XI-C, L.P. ("WP XI-C" and, together with WP XI, WP XI-B, WP XI Partners and Warburg Pincus XI Partners, the "WP XI Funds").

F4 · ownership.nature: The WP XI Funds, Bull Co-Invest, Bull Holdco, WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are collectively referred to herein as the "Warburg Pincus Entities."

F5 · ownership.nature: Each Warburg Pincus Entity disclaims beneficial ownership with respect to any shares of Common Stock of the Issuer, except to the extent of its pecuniary interest in such shares of Common Stock, if any. The WP XI Funds, Bull Co-Invest, Bull Holdco, WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are directors-by-deputization solely for purposes of Section 16 of the Securities Exchange Act of 1934, as amended. Information with respect to each of the Warburg Pincus Entities is given solely by such Warburg Pincus Entity, and no Warburg Pincus Entity has responsibility for the accuracy or completeness of information supplied by another Warburg Pincus Entity.

F6 · ownership.nature: Warburg Pincus XI-C, LLC ("WP XI-C LLC"), is the general partner of WP XI Cayman GP. Warburg Pincus Partners II (Cayman), L.P. ("WPP II Cayman"), is the managing member of WP XI-C LLC. Warburg Pincus (Bermuda) Private Equity GP Ltd. ("WP Bermuda GP"), is the general partner of WPP II Cayman. WP Bull Manager LLC ("WP Bull Manager"), is the general partner of Bull Co-Invest. WP is managing member of WP Bull Manager. Warburg Pincus LLC, a New York limited liability company ("WP LLC"), is the manager of the WP XI Funds. The WP XI Funds share limited partnership ownership in Bull Holdco on a pro rata basis in accordance with their respective numbers of Contributed Shares.

SEC source: 0001999371-26-005534 · ownership.xml · nonDerivative · entry 1

WARBURG PINCUS & CO. · CIK 0000929408 · Director · 10% owner

Warburg Pincus (Bermuda) Private Equity GP Ltd. · CIK 0001555729 · Director · 10% owner

Warburg Pincus (Cayman) XI, L.P. · CIK 0001554853 · Director · 10% owner

WARBURG PINCUS LLC · CIK 0001162870 · Director · 10% owner

Warburg Pincus Partners GP LLC · CIK 0001621224 · Director · 10% owner

Warburg Pincus Partners II (Cayman), L.P. · CIK 0001658820 · Director · 10% owner

Warburg Pincus Private Equity XI-C, L.P. · CIK 0001550877 · Director · 10% owner

Warburg Pincus XI-C, LLC · CIK 0001554852 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 19,102,952

F1 · shares: On March 6, 2026, certain of the Warburg Pincus Entities (as defined below) sold a total of 15,000,000 shares of Common Stock of Sotera Health Company (the "Issuer") in an underwritten public secondary offering (the "Offering").

F2 · balance_after: Following the Offering, consists of (i) 15,287,717 shares of Common Stock of the Issuer held by Bull Holdco L.P. ("Bull Holdco") and (iii) 3,815,235 shares of Common Stock of the Issuer held by Bull Co-Invest L.P., a Delaware limited partnership ("Bull Co-Invest").

F3 · ownership.nature: Warburg Pincus XI, L.P., a Delaware limited partnership ("WP XI GP"), is the general partner of each of (i) Warburg Pincus Private Equity XI, L.P. ("WP XI"), (ii)Warburg Pincus Private Equity XI-B, L.P. ("WP XI-B"), (iii) WP XI Partners, L.P. ("WP XI Partners") and (iv) Warburg Pincus XI Partners, L.P. ("Warburg Pincus XI Partners"). WP Global LLC ("WP Global"), is the general partner of WP XI GP. Warburg Pincus Partners II, L.P. ("WPP II"), is the managing member of WP Global.Warburg Pincus Partners GP LLC ("WPP GP LLC"), is the general partner of WPP II. Warburg Pincus & Co. ("WP"), is the managing member of WPP GP LLC.Warburg Pincus (Cayman) XI, L.P. ("WP XI Cayman GP"), is the general partner of Warburg Pincus Private Equity XI-C, L.P. ("WP XI-C" and, together with WP XI,WP XI-B, WP XI Partners and Warburg Pincus XI Partners, the "WP XI Funds").

F4 · ownership.nature: The WP XI Funds, Bull Co-Invest, Bull Holdco, WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are collectively referred to herein as the "Warburg Pincus Entities."

F5 · ownership.nature: Each Warburg Pincus Entity disclaims beneficial ownership with respect to any shares of Common Stock of the Issuer, except to the extent of its pecuniary interest in such shares of Common Stock, if any. The WP XI Funds, Bull Co-Invest, Bull Holdco, WP Global, WPP II, WPP GP LLC, WP XI Cayman GP, WP XI-C LLC, WPP II Cayman, WP Bermuda GP, WP Bull Manager, WP LLC and WP are directors-by-deputization solely for purposes of Section 16 of the Securities Exchange Act of 1934, as amended. Information with respect to each of the Warburg Pincus Entities is given solely by such Warburg Pincus Entity, and no Warburg Pincus Entity has responsibility for the accuracy or completeness of information supplied by another Warburg Pincus Entity.

F6 · ownership.nature: Warburg Pincus XI-C, LLC ("WP XI-C LLC"), is the general partner of WP XI Cayman GP. Warburg Pincus Partners II (Cayman), L.P. ("WPP II Cayman"), is the managing member of WP XI-C LLC. Warburg Pincus (Bermuda) Private Equity GP Ltd. ("WP Bermuda GP"), is the general partner of WPP II Cayman. WP Bull Manager LLC ("WP Bull Manager"), is the general partner of Bull Co-Invest. WP is managing member of WP Bull Manager. Warburg Pincus LLC, a New York limited liability company ("WP LLC"), is the manager of the WP XI Funds. The WP XI Funds share limited partnership ownership in Bull Holdco on a pro rata basis in accordance with their respective numbers of Contributed Shares.

SEC source: 0001193125-26-100568 · ownership.xml · nonDerivative · entry 1

GTCR INVESTMENT XI LLC · CIK 0001827977 · Director · 10% owner

GTCR FUND XI/A LP · CIK 0001591434 · Director · 10% owner

GTCR FUND XI/C LP · CIK 0001591436 · Director · 10% owner

GTCR CO-INVEST XI LP · CIK 0001591432 · Director · 10% owner

GTCR PARTNERS XI/A&C LP · CIK 0001828028 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 12,735,301

F1 · shares: On March 6, 2026, the GTCR XI Funds (as defined below) sold a total of 10,000,000 shares of Common Stock of Sotera Health Company (the "Issuer") in an underwritten public secondary offering (the "Offering").

F2 · balance_after: Following the Offering, consists of (i) 10,107,727 shares of Common Stock held directly by GTCR Fund XI/A LP, a Delaware limited partnership ("Fund XI/A"), (ii) 2,546,564 shares of Common Stock held directly by GTCR Fund XI/C LP, a Delaware limited partnership ("Fund XI/C"), and (iii) 81,010 shares of Common Stock held directly by GTCR Co-Invest XI LP, a Delaware limited partnership ("Co-Invest XI", and together with Fund XI/A and Fund XI/C, the "GTCR XI Funds").

F3 · ownership.nature: GTCR Partners XI/A&C LP ("Partners XI/A&C") is the general partner of each of Fund XI/A and Fund XI/C. GTCR Investment XI LLC ("Investment XI" and together with the GTCR XI Funds and Partners XI/A&C, the "GTCR Entities"), is the general partner of Co-Invest XI and Partners XI/A&C. Investment XI is managed by a board of managers (the "GTCR Board of Managers") consisting of Mark M. Anderson, Aaron D. Cohen, Sean L. Cunningham, David A Donnini, Constantine S. Mihas and Collin E. Roche, and no single person has voting or dispositive authority over the shares of Common Stock.

F4 · ownership.nature: Each of GTCR Partners XI/A&C, GTCR Investment XI and the GTCR Board of Managers may be deemed to share beneficial ownership of the shares of Common Stock held of record by the GTCR XI Funds, and each of the individual members of the GTCR Board of Managers disclaims beneficial ownership of the shares of Common Stock held of record by the GTCR XI Funds except to the extent of his pecuniary interest therein.

F5 · ownership.nature: Each of the reporting persons is a director-by-deputization solely for purposes of Section 16 of the Exchange Act. Information with respect to each of the GTCR Entities is given solely by such GTCR Entity, and no GTCR Entity has responsibility for the accuracy or completeness of information supplied by another GTCR Entity.

SEC source: 0001193125-26-092207 · ownership.xml · derivative · entry 7

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 29,678

Underlying: Common Stock · 29,678 shares

Expires not disclosed

F7 · derivative.exercise_price: These securites consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, prusuant 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

F7 · shares: These securites consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, prusuant 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

F7 · derivative.exercise_date: These securites consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, prusuant 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

F7 · derivative.expiration_date: These securites consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, prusuant 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

SEC source: 0001193125-26-092207 · ownership.xml · derivative · entry 6

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,958

Underlying: Common Stock · 17,937 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 17,937 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 17,937 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · derivative.exercise_date: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 17,937 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · derivative.expiration_date: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 17,937 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092207 · ownership.xml · nonDerivative · entry 5

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 228,620

F6 · shares: These securities consist of RSUs that were granted on March 2, 2026, 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 2027.

SEC source: 0001193125-26-092207 · ownership.xml · nonDerivative · entry 4

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 169,265

F5 · shares: 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 18,684 RSUs granted to the Reporting Person on March 3, 2025. This award was granted 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.

SEC source: 0001193125-26-092207 · ownership.xml · nonDerivative · entry 3

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 177,505

F4 · shares: 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 53,811 RSUs granted to the Reporting Person on March 3, 2025. This award was granted pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to recieve one share of Common Stock, subject to vesting conditions or performance, as applicable.

SEC source: 0001193125-26-092207 · ownership.xml · nonDerivative · entry 2

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 201,493

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · shares: A portion of the Reporting Person's March 3, 2025 additional performance-based RSUs vested on March 2, 2026 based upon the achievement of performance conditions. As a result, the Reporting Person received an additional 17,937 shares of Common Stock.

F3 · shares: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 17,937 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 17,937 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092207 · ownership.xml · nonDerivative · entry 1

Lyons Jonathan M. · CIK 0001983511 · Sr. Vice President, CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 183,556

F1 · shares: 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") 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.

SEC source: 0001193125-26-092210 · ownership.xml · derivative · entry 4

DIMITRIEF ALEXANDER · CIK 0001614732 · SVP, General Counsel and Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,210

Underlying: Common Stock · 16,816 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 16,816 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F4 · price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 16,816 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F4 · derivative.exercise_date: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 16,816 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F4 · derivative.expiration_date: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 16,816 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092210 · ownership.xml · nonDerivative · entry 3

DIMITRIEF ALEXANDER · CIK 0001614732 · SVP, General Counsel and Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 319,981

F3 · shares: 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 50,448 RSUs granted to the Reporting Person on March 3, 2025. This award was granted pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to recieve one share of Common Stock, subject to vesting conditions or performance, as applicable.

SEC source: 0001193125-26-092210 · ownership.xml · nonDerivative · entry 2

DIMITRIEF ALEXANDER · CIK 0001614732 · SVP, General Counsel and Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 343,600

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · shares: A portion of the Reporting Person's March 3, 2025 additional performance-based RSUs vested on March 2, 2026 based upon the achievement of performance conditions. As a result, the Reporting Person received an additional 16,816 shares of Common Stock.

F4 · shares: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 16,816 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F4 · price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 16,816 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092210 · ownership.xml · nonDerivative · entry 1

DIMITRIEF ALEXANDER · CIK 0001614732 · SVP, General Counsel and Sec.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 326,784

F1 · shares: 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 17,135 Restricted Stock Units ("RSUs") 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 recieve one share of Common Stock, subject to vesting conditions.

SEC source: 0001193125-26-092194 · ownership.xml · derivative · entry 7

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,612

Underlying: Common Stock · 22,612 shares

Expires not disclosed

F7 · derivative.exercise_price: These securities consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

F7 · shares: These securities consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

F7 · derivative.exercise_date: These securities consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

F7 · derivative.expiration_date: These securities consist of the maximum number of additional performance-based RSUs that were granted on March 2, 2026, 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 conditions. The additional RSUs generally vest annually in 60%, 20% and 20% installments, respectfully, commencing March 2027, subject to performance.

SEC source: 0001193125-26-092194 · ownership.xml · derivative · entry 6

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,716

Underlying: Common Stock · 14,573 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F6 · derivative.exercise_price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 14,573 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F6 · price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 14,573 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F6 · derivative.exercise_date: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 14,573 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F6 · derivative.expiration_date: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 14,573 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092194 · ownership.xml · nonDerivative · entry 5

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 484,279

F5 · shares: These securities consist of RSUs that were granted on March 2, 2026, 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 2027.

SEC source: 0001193125-26-092194 · ownership.xml · nonDerivative · entry 4

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 439,056

F4 · shares: 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 43,720 RSUs granted to the Reporting Person on March 3, 2025. This award was granted pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to recieve one share of Common Stock, subject to vesting conditions or performance, as applicable.

SEC source: 0001193125-26-092194 · ownership.xml · nonDerivative · entry 3

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 456,553

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · shares: A portion of the Reporting Person's March 3, 2025 additional performance-based RSUs vested on March 2, 2026 based upon the achievement of performance conditions. As a result, the Reporting Person received an additional 14,573 shares of Common Stock.

F6 · shares: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 14,573 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F6 · price: These securities consist 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 represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the additional RSUs, the Reporting Person vested in 14,573 shares of Common Stock on March 2, 2026. The remaining additional RSUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092194 · ownership.xml · nonDerivative · entry 2

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 441,980

F2 · shares: 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 11,423 RSUs granted to the Reporting Person on March 4, 2024. This award was granted 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.

SEC source: 0001193125-26-092194 · ownership.xml · nonDerivative · entry 1

Rutz Michael P · CIK 0001599220 · President of Sterigenics

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 446,475

F1 · shares: 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 9,475 Restricted Stock Units ("RSUs") granted to the Reporting Person on March 6, 2023. 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.

SEC source: 0001193125-26-092231 · ownership.xml · derivative · entry 9

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 120,124

Underlying: Common Stock · 120,124 shares

Expires not disclosed

F7 · derivative.exercise_price: These securities consist of a maximum number of SAUs that were granted on March 2, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock, subject to stock price-related peformance conditions. The SAUs generally vest annually in 60%, 20% and 20% installments, respectively, commencing March 2027, subject to performance.

F7 · derivative.exercise_date: These securities consist of a maximum number of SAUs that were granted on March 2, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock, subject to stock price-related peformance conditions. The SAUs generally vest annually in 60%, 20% and 20% installments, respectively, commencing March 2027, subject to performance.

F7 · derivative.expiration_date: These securities consist of a maximum number of SAUs that were granted on March 2, 2026, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to receive one share of Common Stock, subject to stock price-related peformance conditions. The SAUs generally vest annually in 60%, 20% and 20% installments, respectively, commencing March 2027, subject to performance.

SEC source: 0001193125-26-092231 · ownership.xml · derivative · entry 8

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 59,790

Underlying: Common Stock · 89,686 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: These securities consist of performance-based share appreciation units ("SAUs") (formerly called performance stock units) that were granted on March 3, 2025, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the SAUs, the Reporting Person vested in 89,686 shares of Common Stock on March 2, 2026. The remaining SAUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · price: These securities consist of performance-based share appreciation units ("SAUs") (formerly called performance stock units) that were granted on March 3, 2025, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the SAUs, the Reporting Person vested in 89,686 shares of Common Stock on March 2, 2026. The remaining SAUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · derivative.exercise_date: These securities consist of performance-based share appreciation units ("SAUs") (formerly called performance stock units) that were granted on March 3, 2025, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the SAUs, the Reporting Person vested in 89,686 shares of Common Stock on March 2, 2026. The remaining SAUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · derivative.expiration_date: These securities consist of performance-based share appreciation units ("SAUs") (formerly called performance stock units) that were granted on March 3, 2025, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the SAUs, the Reporting Person vested in 89,686 shares of Common Stock on March 2, 2026. The remaining SAUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092231 · ownership.xml · nonDerivative · entry 6

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 692,427

F6 · shares: These securities consist of RSUs that were granted on March 2, 2026, 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 2027.

SEC source: 0001193125-26-092231 · ownership.xml · nonDerivative · entry 5

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 452,179

F5 · shares: 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 179,372 RSUs granted to the Reporting Person on March 3, 2025. This award was granted pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to recieve one share of Common Stock, subject to vesting conditions.

SEC source: 0001193125-26-092231 · ownership.xml · nonDerivative · entry 4

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 531,283

F4 · shares: 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 89,686 SAUs granted to the Reporting Person on March 3, 2025. This award was granted pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represents the Reporting Person's right to recieve one share of Common Stock, subject to performance.

SEC source: 0001193125-26-092231 · ownership.xml · nonDerivative · entry 3

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 570,835

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · shares: These securities consist of performance-based share appreciation units ("SAUs") (formerly called performance stock units) that were granted on March 3, 2025, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the SAUs, the Reporting Person vested in 89,686 shares of Common Stock on March 2, 2026. The remaining SAUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

F3 · price: These securities consist of performance-based share appreciation units ("SAUs") (formerly called performance stock units) that were granted on March 3, 2025, pursuant to the terms of a SAU Agreement under the 2020 Incentive Plan. Each SAU represented the Reporting Person's right to receive one share of Common Stock subject to stock price-related performance conditions. Regarding the SAUs, the Reporting Person vested in 89,686 shares of Common Stock on March 2, 2026. The remaining SAUs under the award vest annually in equal installments in March 2027 and March 2028, subject to performance.

SEC source: 0001193125-26-092231 · ownership.xml · nonDerivative · entry 2

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 481,149

F2 · shares: 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 91,386 RSUs granted to the Reporting Person on March 4, 2024. This award was granted pursuant to the terms of an RSU agreement under the 2020 Incentive Plan. Each RSU represents the Reporting Person's right to recieve one share of Common Stock, subject to vesting conditions.

SEC source: 0001193125-26-092231 · ownership.xml · nonDerivative · entry 1

Petras Michael B. Jr. · CIK 0001832387 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 521,451

F1 · shares: 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 71,063 Restricted Stock Units ("RSUs") granted to the Reporting Person on March 6, 2023. This award was granted pursuant to the terms of an RSU agreement under the Sotera Health Company 2020 Incentive Plan ("2020 Incentive Plan"). Each RSU represents the Reporting Person's right to receive one share of Common Stock, subject to vesting conditions