# EDGAR Filing Document

**Accession Number:** 0001540166
**File Stem:** 0001999371-25-017526
**Filing Date:** 2025-11
**Character Count:** 32792
**Document Hash:** 9dcc22c5b18abe2035f4b61a83f8bceb
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001999371-25-017526.hdr.sgml**: 20251112

**ACCESSION NUMBER**: 0001999371-25-017526

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20251110

**FILED AS OF DATE**: 20251112

**DATE AS OF CHANGE**: 20251112

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** WARBURG PINCUS & CO.
- **CENTRAL INDEX KEY:** 0000929408

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** NY
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472841

**BUSINESS ADDRESS:**
- **STREET 1:** 450 LEXINGTON AVENUE
- **STREET 2:** NEW YORK
- **CITY:** NY
- **STATE:** NY
- **ZIP:** 100173147
- **BUSINESS PHONE:** 2128780600

**MAIL ADDRESS:**
- **STREET 1:** 450 LEXINGTON AVENUE
- **STREET 2:** NEW YORK
- **CITY:** NY
- **STATE:** NY
- **ZIP:** 100173147

**FORMER NAME:**
- **FORMER CONFORMED NAME:** WARBURG PINCUS & CO
- **DATE OF NAME CHANGE:** 19940901
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Warburg Pincus Private Equity XI, L.P.
- **CENTRAL INDEX KEY:** 0001540163

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472840

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** WP XI Partners, L.P.
- **CENTRAL INDEX KEY:** 0001540164

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472839

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Warburg Pincus Private Equity XI-B, L.P.
- **CENTRAL INDEX KEY:** 0001540166

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472837

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Warburg Pincus XI, L.P.
- **CENTRAL INDEX KEY:** 0001540167

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472834

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** 450 LEXINGTON AVENUE
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Bull Holdco L.P.
- **CENTRAL INDEX KEY:** 0002014247

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472835

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 2128780600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Warburg Pincus XI Partners, L.P.
- **CENTRAL INDEX KEY:** 0001540386

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472838

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017

**FORMER NAME:**
- **FORMER CONFORMED NAME:** WArburg Pincus XI Partners, L.P.
- **DATE OF NAME CHANGE:** 20120125
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Warburg Pincus Partners II, L.P.
- **CENTRAL INDEX KEY:** 0001658787

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472832

**BUSINESS ADDRESS:**
- **STREET 1:** 450 LEXINGTON AVENUE
- **STREET 2:** C/O WARBURG PINCUS LLC
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 2128780600

**MAIL ADDRESS:**
- **STREET 1:** 450 LEXINGTON AVENUE
- **STREET 2:** C/O WARBURG PINCUS LLC
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** WP Global LLC
- **CENTRAL INDEX KEY:** 0001540385

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472833

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Bull Co-Invest L.P.
- **CENTRAL INDEX KEY:** 0001832693

**ORGANIZATION NAME:**
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39729
- **FILM NUMBER:** 251472836

**BUSINESS ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
- **BUSINESS PHONE:** 212-878-0600

**MAIL ADDRESS:**
- **STREET 1:** C/O WARBURG PINCUS LLC
- **STREET 2:** 450 LEXINGTON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10017
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Sotera Health Co
- **CENTRAL INDEX KEY:** 0001822479
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-MISC HEALTH & ALLIED SERVICES, NEC [8090]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 473531161
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 9100 SOUTH HILLS BLVD, SUITE 300
- **CITY:** BROADVIEW HEIGHTS
- **STATE:** OH
- **ZIP:** 44147
- **BUSINESS PHONE:** 440-262-1410

**MAIL ADDRESS:**
- **STREET 1:** 9100 SOUTH HILLS BLVD, SUITE 300
- **CITY:** BROADVIEW HEIGHTS
- **STATE:** OH
- **ZIP:** 44147

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Sotera Health Topco, Inc.
- **DATE OF NAME CHANGE:** 20200824

## Exhibit 99.1

**Exhibit 99.1**

**List of Reporting Owners and Signature Page**

Name of designated filer: Warburg Pincus & Co.

Other joint filers: Warburg Pincus Private Equity XI, L.P., WP XI Partners, L.P., Warburg Pincus XI Partners, L.P., Warburg Pincus Private Equity XI-B, L.P., Bull Co-Invest L.P., Bull Holdco, L.P., Warburg Pincus XI, L.P., WP Global LLC, Warburg Pincus Partners II, L.P.

Address for each joint filer is: c/o Warburg Pincus & Co., 450 Lexington Avenue, New York, New York 10017

Issuer Name and Ticker or Trading Symbol: Sotera Health Co [SHC]

---

| | | |
|:---|:---|:---|
| <br>**WARBURG PINCUS & CO.** | <br>**WARBURG PINCUS & CO.** |  |
| By: | <u>/s/ Harsha G. Marti</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | \*\* Signature of Reporting Person | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| <br> **WARBURG PINCUS PRIVATE EQUITY XI, L.P.** | <br> **WARBURG PINCUS PRIVATE EQUITY XI, L.P.** |  |
| By: | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner |
| By: | &nbsp;&nbsp;WP Global LLC, its general partner | &nbsp;&nbsp;WP Global LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| By: | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| By: | <u>/s/ Harsha G. Marti</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | \*\* Signature of Reporting Person | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| <br> **WP XI PARTNERS, L.P.** | <br> **WP XI PARTNERS, L.P.** | <br> **WP XI PARTNERS, L.P.** |
| By: | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner |
| By: | &nbsp;&nbsp;WP Global LLC, its general partner | &nbsp;&nbsp;WP Global LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| By: | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| By: | <u>/s/ Harsha G. Marti</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | \*\* Signature of Reporting Person | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **WARBURG PINCUS XI PARTNERS, L.P.** | **WARBURG PINCUS XI PARTNERS, L.P.** | **WARBURG PINCUS XI PARTNERS, L.P.** |
| By: | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner |
| By: | &nbsp;&nbsp;WP Global LLC, its general partner | &nbsp;&nbsp;WP Global LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| By: | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| By: | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **WARBURG PINCUS PRIVATE EQUITY XI-B, L.P.** | **WARBURG PINCUS PRIVATE EQUITY XI-B, L.P.** | **WARBURG PINCUS PRIVATE EQUITY XI-B, L.P.** |
| By: | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner |
| By: | &nbsp;&nbsp;WP Global LLC, its general partner | &nbsp;&nbsp;WP Global LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| By: | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
|  | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| By: | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **BULL CO-INVEST, L.P.** | **BULL CO-INVEST, L.P.** | **BULL CO-INVEST, L.P.** |
| By: | &nbsp;&nbsp;WP Bull Manager, LLC, its general partner | &nbsp;&nbsp;WP Bull Manager, LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| By: | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **BULL HOLDCO, L.P.** | **BULL HOLDCO, L.P.** | **BULL HOLDCO, L.P.** |
| By: | &nbsp;&nbsp;WP Bull Holdco GP LLC, its general partner | &nbsp;&nbsp;WP Bull Holdco GP LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Private Equity XI, L.P., its sole and managing member | &nbsp;&nbsp;Warburg Pincus Private Equity XI, L.P., its sole and managing member |
| By: | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner | &nbsp;&nbsp;Warburg Pincus XI, L.P., its general partner |
| By: | &nbsp;&nbsp;WP Global LLC, its general partner | &nbsp;&nbsp;WP Global LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| By: | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| By: | &nbsp;&nbsp;By: Warburg Pincus & Co., its managing member | &nbsp;&nbsp;By: Warburg Pincus & Co., its managing member |
| By: | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **WARBURG PINCUS XI, L.P.** | **WARBURG PINCUS XI, L.P.** | **WARBURG PINCUS XI, L.P.** |
| By: | &nbsp;&nbsp;WP Global LLC, its general partner | &nbsp;&nbsp;WP Global LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| By: | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| By: | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| By: | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
|  | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| Name: | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| Title: | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **WP GLOBAL LLC** | **WP GLOBAL LLC** | **WP GLOBAL LLC** |
| &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member | &nbsp;&nbsp;Warburg Pincus Partners II, L.P., its managing member |
| &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| <u>/s/ Harsha G. Marti</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
| \*\* Signature of Reporting Person | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner | &nbsp;&nbsp;Partner |
| **WARBURG PINCUS PARTNERS II, L.P.** | **WARBURG PINCUS PARTNERS II, L.P.** | **WARBURG PINCUS PARTNERS II, L.P.** |
| &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner | &nbsp;&nbsp;Warburg Pincus Partners GP LLC, its general partner |
| &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member | &nbsp;&nbsp;Warburg Pincus & Co., its managing member |
| <u>/s/ Harsha G. Marti</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> | &nbsp;&nbsp;&nbsp;<u>11/12/2025</u> |
| \*\* Signature of Reporting Person | &nbsp;&nbsp;&nbsp;Date | &nbsp;&nbsp;&nbsp;Date |
| &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti | &nbsp;&nbsp;Harsha G. Marti |
| &nbsp;&nbsp;Managing Director | &nbsp;&nbsp;Managing Director | &nbsp;&nbsp;Managing Director |

---

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>WARBURG PINCUS & CO.<br><sub>(Last) (First) (Middle)</sub><br>450 LEXINGTON AVENUE<br>NEW YORK<br><sub>(Street)</sub><br>NY, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Warburg Pincus Private Equity XI, L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>450 LEXINGTON AVENUE, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>WP XI Partners, L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>450 LEXINGTON AVENUE, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Warburg Pincus XI Partners, L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Warburg Pincus Private Equity XI-B, L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>450 LEXINGTON AVENUE, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Bull Co-Invest L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Bull Holdco L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Warburg Pincus XI, L.P.<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>450 LEXINGTON AVENUE, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>WP Global LLC<br><sub>(Last) (First) (Middle)</sub><br>C/O WARBURG PINCUS LLC<br>450 LEXINGTON AVENUE<br><sub>(Street)</sub><br>NEW YORK, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Warburg Pincus Partners II, L.P.<br><sub>(Last) (First) (Middle)</sub><br>450 LEXINGTON AVENUE<br>C/O WARBURG PINCUS LLC<br><sub>(Street)</sub><br>NEW YORK, NY 10017<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-11-10 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sotera Health Co [ SHC ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock, $0.01 par value per share ("Common Stock") | 2025-11-10 |  | S |  | 18000000<sup>(1)</sup> | D | $15.651 | 43822952<sup>(2)</sup> | I | See Footnote<sup>(3)(4)(5)(6)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) On November 10, 2025, certain of the Warburg Pincus Entities (as defined below) sold a total of 18,000,000 shares of Common Stock of Sotera Health Company (the "Issuer") in an underwritten public secondary offering (the "Offering").

(2) Following the Offering, consists of (i) 14,405,046 shares of Common Stock of the Issuer held by Bull Holdco L.P. ("Bull Holdco") and (ii) 3,594,954 shares of Common Stock of the Issuer held by Bull Co-Invest L.P., a Delaware limited partnership ("Bull Co-Invest").

(3) 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").

(4) 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."

(5) 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.

(6) 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.

**Remarks:**
Form 1 of 2. Two reports are filed that relate to the same transactions. See Form 2 of 2 for additional reporting entities.

**Signature:** See Exhibit 99.1  
**Date:** 2025-11-12

### Remarks:

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**