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]

WARBURG PINCUS & CO.


By:				/s/ Harsha G. Marti			11/12/2025
				** Signature of Reporting Person			Date
Name:				Harsha G. Marti
Title:				Partner

WARBURG PINCUS PRIVATE EQUITY XI, L.P.

By:				Warburg Pincus XI, L.P., its general partner
By:				WP Global LLC, its general partner
By:				Warburg Pincus Partners II, L.P., its managing member
By:				Warburg Pincus Partners GP LLC, its general partner
By:				Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti			11/12/2025
				** Signature of Reporting Person			Date
Name:				Harsha G. Marti
Title:				Partner

WP XI PARTNERS, L.P.

By:				Warburg Pincus XI, L.P., its general partner
By:				WP Global LLC, its general partner
By:				Warburg Pincus Partners II, L.P., its managing member
By:				Warburg Pincus Partners GP LLC, its general partner
By:				Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti			11/12/2025
				** Signature of Reporting Person			Date
Name:				Harsha G. Marti
Title:				Partner


WARBURG PINCUS XI PARTNERS, L.P.

By:				Warburg Pincus XI, L.P., its general partner
By:				WP Global LLC, its general partner
By:				Warburg Pincus Partners II, L.P., its managing member
By:				Warburg Pincus Partners GP LLC, its general partner
By:				Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti	11/12/2025
				** Signature of Reporting Person	Date
Name:				Harsha G. Marti
Title:				Partner


WARBURG PINCUS PRIVATE EQUITY XI-B, L.P.

By:				Warburg Pincus XI, L.P., its general partner
By:				WP Global LLC, its general partner
By:				Warburg Pincus Partners II, L.P., its managing member
By:				Warburg Pincus Partners GP LLC, its general partner
				Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti	11/12/2025
				** Signature of Reporting Person	Date
Name:				Harsha G. Marti
Title:				Partner


BULL CO-INVEST, L.P.

By:				WP Bull Manager, LLC, its general partner
By:				Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti	11/12/2025
				** Signature of Reporting Person	Date
Name:				Harsha G. Marti
Title:				Partner


BULL HOLDCO, L.P.

By:				WP Bull Holdco GP LLC, its general partner
By:				Warburg Pincus Private Equity XI, L.P., its sole and managing member
By:				Warburg Pincus XI, L.P., its general partner
By:				WP Global LLC, its general partner
By:				Warburg Pincus Partners II, L.P., its managing member
By:				Warburg Pincus Partners GP LLC, its general partner
By:				By: Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti	11/12/2025
				** Signature of Reporting Person	Date
Name:				Harsha G. Marti
Title:				Partner


WARBURG PINCUS XI, L.P.

By:				WP Global LLC, its general partner
By:				Warburg Pincus Partners II, L.P., its managing member
By:				Warburg Pincus Partners GP LLC, its general partner
By:				Warburg Pincus & Co., its managing member

By:				/s/ Harsha G. Marti	11/12/2025
				** Signature of Reporting Person	Date
Name:				Harsha G. Marti
Title:				Partner


	WP GLOBAL LLC
	By:	Warburg Pincus Partners II, L.P., its managing member
	By:	Warburg Pincus Partners GP LLC, its general partner
	By:	Warburg Pincus & Co., its managing member

	By:		/s/ Harsha G. Marti			11/12/2025
			** Signature of Reporting Person			Date
	Name:	Harsha G. Marti
	Title:	Partner


	WARBURG PINCUS PARTNERS II, L.P.
	By:	Warburg Pincus Partners GP LLC, its general partner
	By:	Warburg Pincus & Co., its managing member

	By:		/s/ Harsha G. Marti			11/12/2025
			** Signature of Reporting Person			Date
	Name:	Harsha G. Marti
	Title:	Managing Director

WARBURG PINCUS & CO. 4