Form 4 Filing for Rebecca Underwood of Clean Harbors Inc.

Rebecca Underwood, PRESIDENT & EVP FACILITIES at Clean Harbors Inc. (CLH), reported a disposition of 311 shares of Common Stock on July 1, 2026. The transaction, coded as "F" (likely for payment of tax liability by withholding of securities incident to vesting), occurred at a price of $290.74 per share. Following this transaction, Ms. Underwood directly owns 18,373 shares of CLH stock. The filing was signed on July 6, 2026.