Exhibit 99.1 Sotera Health Reports First-Quarter 2024 Results • Q1 2024 net revenues increased 12.5% to $248 million, compared to Q1 2023 • Q1 2024 net income of $6 million or $0.02 per diluted share, compared to net income of $3 million or $0.01 per diluted share in Q1 2023 • Q1 2024 Adjusted EBITDA(1) increased 13.7% to $112 million, compared to Q1 2023 • Q1 2024 Adjusted EPS(1) of $0.13 compared to Adjusted EPS of $0.13 in Q1 2023 • Company reaffirms 2024 outlook CLEVELAND, OH, May 2, 2024 – Sotera Healt ...