Rebecca Underwood - 01 Feb 2026 Form 4 Insider Report for CLEAN HARBORS INC (CLH)

Role: PRESIDENT & EVP FACILITIES
Signature: /s/ Rebecca Underwood
Issuer symbol: CLH
Transactions as of: 01 Feb 2026
Net transactions value: -$110,462
Form type: 4
Filing time: 03 Feb 2026, 15:38:37 UTC
Previous filing: 17 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Underwood Rebecca	PRESIDENT & EVP FACILITIES	42 LONGWATER DR, NORWELL	/s/ Rebecca Underwood	03 Feb 2026	0001990612

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	CLH	Common Stock	Tax liability	$110,462	-425	-2.5%	$259.91	16,859	02 Feb 2026	Direct	F1
transaction	CLH	Common Stock	Award	$0	+2,513	+15%	$0.000000	19,372	01 Feb 2026	Direct	F2
transaction	CLH	Common Stock	Award	$0	+838	+4.3%	$0.000000	20,210	01 Feb 2026	Direct	F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Payment of tax liability by withholding of securities incident to vesting of securities in accordance with Rule 16b3.
F2	Performance-Based Restricted Stock Award that will vest 50% on 3/15/2028 and 50% on 3/15/2029, depending on achievement of certain goals during the performance period 1/1/2027 through 12/31/2027
F3	Restricted Stock Award vesting as to 25% on February 1, 2027; 25% on February 1, 2028; 25% on February 1, 2029; and 25% on February 1, 2030.