Exhibit 4.3

EXECUTION VERSION

NINTH AMENDMENT TO SECOND AMENDED AND RESTATED REVOLVING

CREDIT, TERM LOAN AND SECURITY AGREEMENT

THIS NINTH AMENDMENT TO SECOND AMENDED AND RESTATED REVOLVING CREDIT, TERM LOAN AND SECURITY AGREEMENT, dated as of November 12, 2024 (this “Amendment”), relating to the Credit Agreement referenced below, is by and among PERMA-FIX ENVIRONMENTAL SERVICES, INC., a Delaware corporation (the “Borrower”), and PNC Bank, National Association, a national banking association, as agent (in such capacity, the “Agent”) and the lender (in such capacity, the “Lender”). Terms used herein but not otherwise defined herein shall have the meanings provided to such terms in the Credit Agreement.

W I T N E S S E T H

WHEREAS, a credit facility has been extended to the Borrower pursuant to the terms of that certain Second Amended and Restated Revolving Credit, Term Loan and Security Agreement dated as of May 8, 2020 (as amended and modified from time to time, the “Credit Agreement”) among the Borrower, the Lender identified therein, and PNC Bank, National Association, as agent and Lender;

WHEREAS, the Borrower has requested certain modifications to the Credit Agreement; and

WHEREAS, the Lender has agreed to the requested modifications on the terms and conditions set

forth herein;

NOW, THEREFORE, IN CONSIDERATION of the premises and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

1. Amendments. The Credit Agreement is amended as set forth below.

(a) The definition of “Trigger Date” appearing in Section 1.2 thereof is amended to read as follows:

“‘Trigger Date’ means the first to occur of (a) the date, if any, on which the Borrower delivers to Agent evidence that Borrower and its Subsidiaries have maintained a Fixed Charge Coverage Ratio of not less than 1.15 to 1.00 for trailing twelve-month period most recently ended, which evidence shall be in form and substance satisfactory to the Agent in its sole discretion and (b) September 30, 2025.”

(b) Section 6.5(a) is amended to read as follows:

“(a) Liquidity.

Maintain Liquidity in an amount not less than $3,000,000 at all times on and after June 30, 2024 to (but excluding) the Trigger Date; provided, that, each such determination of Liquidity pursuant to the foregoing clauses (i) and (ii) shall include at least $500,000 of Undrawn Availability.”

(c) Section 6.5(b) is amended to read as follows:

“(b) Fixed Charge Coverage Ratio.

Beginning with the fiscal quarter ending December 31, 2024, cause to be maintained a Fixed Charge Coverage Ratio of not less than 1.15 to 1.00 for (i) the one quarter period ending as of December 31, 2024, (ii) the two quarter period ending as of March 31, 2025, (iii) the three quarter period ending as of June 30, 2025, and (iv) the four quarter period ending as of September 30, 2025 and for each fiscal quarter thereafter; provided, that, in the event the Trigger Date occurs at any time prior September 30, 2025, the Fixed Charge Coverage Ratio shall be tested as of the end of each quarter after the Trigger Date for the four quarter period then-ended.”

2. Conditions Precedent. This Amendment shall be effective as of the date hereof upon satisfaction of the following conditions:

(a) the execution of this Amendment by the Borrower and PNC Bank, National Association as the Agent and Lender; and

(b) receipt by the Agent of an amendment fee of $12,500.

3. Representations and Warranties. The Borrower hereby represents and warrants in connection herewith that as of the date hereof (after giving effect hereto) (i) the representations and warranties set forth in Article V of the Credit Agreement are true and correct in all material respects (except those which expressly relate to an earlier date), and (ii) no Default or Event of Default has occurred and is continuing under the Credit Agreement.

4. Acknowledgments, Affirmations and Agreements. The Borrower (i) acknowledges and consents to all of the terms and conditions of this Amendment and (ii) affirms all of its obligations under the Credit Agreement and the Other Documents.

5. Credit Agreement. Except as expressly modified hereby, all of the terms and provisions of the Credit Agreement remain in full force and effect.

6. Expenses. The Borrower agrees to pay all reasonable costs and expenses in connection with the preparation, execution and delivery of this Amendment, including the reasonable fees and expenses of the Agent’s legal counsel.

7. Counterparts. This Amendment may be executed in any number of counterparts, each of which when so executed and delivered shall be deemed an original. It shall not be necessary in making proof of this Amendment to produce or account for more than one such counterpart.

8. Governing Law. This Amendment shall be deemed to be a contract under, and shall for all purposes be construed in accordance with, the laws of the State of New York.

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IN WITNESS WHEREOF, each of the parties hereto has caused a counterpart of this Amendment to be duly executed and delivered as of the date first above written.

Ninth Amendment to Second Amended and Restated Revolving Credit,

Term Loan and Security Agreement (Perma-Fix Environmental Services, Inc.)