Material Event Form 8 K

As a result of the stock sale described below, the number of directors that the Stockholders Agreement of Sotera Health Company (the "Company") entitles GTCR to designate for election to the Board of Directors has decreased from three to two. On September 6, 2024, David A. Donnini, one of GTCR's designees, notified the Company that, consistent with this decrease, he wished to resign as a director. With gratitude for Mr. Donnini's exemplary service, the Company has accepted his resignation, effective September 6, 2024. As contemplated by the Stockholder's Agreement, the size of the Board will decrease from 12 directors to 11. Mr. Donnini advised the Company that his decision did not result from any disagreement with the Company, its management or the Board on any matter, whether related to the Company's operations, policies, practices or otherwise.