Clean Harbors (NYSE: CLH) co-CEO reports new stock awards and tax withholding

Rhea-AI Filing Summary

Clean Harbors, Inc. co-CEO Eric W. Gerstenberg reported several equity compensation moves and related tax withholding. On February 1, 2026, he received 10,290 shares of performance-based restricted stock and 10,690 shares of time-based restricted stock at $0 per share. On February 2, 2026, 4,934 shares were withheld at $259.91 per share to cover tax liabilities tied to vesting. After these transactions, he directly held up to 66,500 shares of Clean Harbors common stock. The performance-based award is scheduled to vest in two equal parts in 2028 and 2029, subject to goal achievement, while the time-based award vests in four equal annual installments from 2027 through 2030.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

GERSTENBERG ERIC W

(Last) (First) (Middle)

C/O CLEAN HARBORS ENVIRON. SERVICES INC.

42 LONGWATER DRIVE

(Street)

NORWELL MA 02061

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CLEAN HARBORS INC [ CLH ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CO-CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/01/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/02/2026		F		4,934(1)	D	$259.91	45,520	D
Common Stock	02/01/2026		A		10,290(2)	A	$0	55,810	D
Common Stock	02/01/2026		A		10,690(3)	A	$0	66,500	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Payment of tax liability by withholding of securities incident to vesting of securities in accordance with Rule 16b3.

2. 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

3. 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.

	/s/ Eric W. Gerstenberg	02/03/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transactions did CLH co-CEO Eric Gerstenberg report?

Eric W. Gerstenberg reported new restricted stock awards and tax withholding transactions. He received 10,290 performance-based restricted shares and 10,690 time-based restricted shares, and had 4,934 shares withheld at $259.91 each to satisfy tax liabilities related to vesting activity.

How many Clean Harbors (CLH) shares does the co-CEO own after these Form 4 transactions?

Following the reported transactions, Eric W. Gerstenberg directly held up to 66,500 shares of Clean Harbors common stock. This figure reflects the cumulative impact of the new restricted stock awards and the 4,934 shares withheld to cover tax obligations associated with securities vesting.

What are the vesting terms of Eric Gerstenberg’s performance-based CLH restricted stock?

The performance-based restricted stock award of 10,290 shares will vest 50% on March 15, 2028 and 50% on March 15, 2029. Vesting depends on achieving specified goals during the performance period from January 1, 2027 through December 31, 2027, as outlined in the award terms.

How do the time-based restricted stock awards for CLH’s co-CEO vest?

The 10,690-share restricted stock award vests in four equal installments. Vesting occurs 25% on February 1, 2027, 25% on February 1, 2028, 25% on February 1, 2029, and 25% on February 1, 2030, rewarding continued service over that multi-year period.

Was the 4,934-share CLH transaction an open market sale by the co-CEO?

No. The 4,934-share transaction was a tax withholding event, not an open market sale. Shares were withheld to pay tax liabilities arising from vesting of securities, in accordance with Rule 16b-3, rather than being sold at the executive’s discretion.

What role does Eric W. Gerstenberg hold at Clean Harbors (CLH)?

Eric W. Gerstenberg serves as an officer of Clean Harbors with the title of co-chief executive officer (Co-CEO). The Form 4 identifies him as an officer, not a director or 10% owner, and reports these equity-related transactions in that capacity.