Michael B. Petras Jr. - 02 Mar 2025 Form 4 Insider Report for Sotera Health Co (SHC)

Footnote F1

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 62,407 Restricted Stock Units ("RSUs"), which represents 33% of the RSU award granted to the Reporting Person on March 2, 2022. 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.

Footnote F2

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 RSUs, which represents 33% of the RSU award granted to the Reporting Person on March 6, 2023. 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.

Footnote F3

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, which represents 33% of the RSU award 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.

Footnote F4

These securities consist of RSUs that were granted on March 3, 2025, 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 3, 2026.

Footnote F5

These securities consist of 552,790 RSUs and 315,813 shares of Common Stock.

Footnote F6

The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purpose.

Footnote F7

These securities consist of a maximum number of Performance Stock Units ("PSUs") that were granted on March 3, 2025, pursuant to the terms of a PSU agreement under the 2020 Incentive Plan. Each PSU represents the Reporting Person's right to receive one share of Common Stock, subject to stock price-related performance conditions. The PSUs generally vest annually in 60%, 20%, and 20% installments, respectively, commencing March 3, 2026, subject to performance.

Footnote F8

No transaction is being reported on this line. Reported on a previously filed Form 4.

Footnote F9

These options were granted on March 4, 2024, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest annually in three equal installments commencing March 2, 2025, subject to vesting conditions.

Footnote F10

These options were granted on March 6, 2023, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest annually in three equal installments commencing March 2, 2024, subject to vesting conditions.

Footnote F11

These options were granted on November 7, 2022, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest in three installments, as follows: 30%, 30%, and 40% of the options vest on each of the 12-month, 18-month, and 24-month anniversaries, respectively, of the date of grant, subject to the Reporting Person's continued service through each such date.

Footnote F12

These options were granted on March 2, 2022, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest in three equal installments on each of the first three anniversaries of the date of grant, subject to vesting conditions.

Footnote F13

These options were granted on November 20, 2020, pursuant to the terms of a stock option agreement under the 2020 Incentive Plan. The options vest in four equal installments on each of the first four anniversaries of the date of grant, subject to vesting conditions.