Exhibit (4)(b) Tenth Amendment dated 1/14/02 to A&R DIP TENTH AMENDMENT AND WAIVER (this "AMENDMENT AND WAIVER") dated as of January 31, 2002, to the Amended and Restated Debtor in Possession Credit Agreement, initially dated as of June 11, 2000, amended and restated as of July 19, 2000, as amended (the "CREDIT AGREEMENT") among SAFETY-KLEEN SERVICES, INC., a Delaware corporation (the "BORROWER"), the financial institutions or entities from time to time parties to this Agreement (the "LENDERS"), THE TORONTO-DOMINION BANK, HOUSTON AGENCY, as letter of credit issuing bank (the "ISSUING LENDER"), TORONTO DOMINION (TEXAS), INC., as administrative agent (the "GENERAL ADMINISTRATIVE AGENT"), and THE CIT GROUP/BUSINESS CREDIT, INC. ("CIT"), as collateral agent and underwriter (the "COLLATERAL AGENT"; collectively with the General Administrative Agent, the "UNDERWRITERS"). W I T N E S S E T H: - - - - - - - - - - WHEREAS, the Borrower has requested that the General Administrative Agent and the Lenders agree to amend certain provisions and waive certain provisions of the Credit Agreement upon the terms and subject to the conditions set forth herein; and WHEREAS, the General Administrative Agent and the Lenders have agreed to such amendments and waivers only upon the terms and subject to the conditions set forth herein. NOW, THEREFORE, in consideration of the premises and the mutual covenants contained herein and in the Credit Agreement, the parties hereto hereby agree as follows: 1. DEFINED TERMS. Unless otherwise defined herein, all capitalized terms used herein shall have the meanings given to them in the Credit Agreement. 2. AMENDMENT OF SECTION 1.1. The definition of "Termination Date" is hereby amended by replacing the date "January 31, 2002" in clause (a) therein with the date "March 15, 2002". 3. AMENDMENTS OF SECTION 9. (a) Subsection 9(p) of the Credit Agreement is hereby amended by replacing the date "January 31, 2002" therein with the date "March 15, 2002". (b) Subsection 9(r) of the Credit Agreement is hereby amended by replacing the date "January 31, 2002" therein with the date "March 15, 2002". 4. WAIVER. The General Administrative Agent and the Required Lenders hereby waive until March 15, 2002 (i) compliance with all provisions of Sections 7.1, 7.2(d) and 7.11 of the Credit Agreement pertaining to the Borrower and (ii) any Default or Event of Default that occurred by virtue of the Borrower's failure to satisfy the requirements of Sections 7.1, 7.2(d) and 7.11 as such Section were in effect prior to this Amendment and Waiver. 3093110-0154-08480-NY03.2148011.3 5. REPRESENTATIONS AND WARRANTIES. After giving effect to this Amendment and Waiver, the Borrower hereby represents and warrants that all of the representations and warranties contained in the Credit Agreement are true and correct in all material respects as of the date hereof (unless stated to relate to a specific earlier date, in which case such representations and warranties shall be true and correct in all material respects as of such earlier date) and that no Default or Event of Default has occurred and is continuing. 6. EFFECTIVENESS. This Amendment and Waiver shall become effective on the date upon which the General Administrative Agent shall have received counterparts hereof duly executed by the Borrower and the Required Lenders. 7. CONTINUING EFFECTS. Except as expressly waived or amended hereby, the Credit Agreement shall continue to be and shall remain in full force and effect in accordance with its terms. 8. Fees and Expenses. The Borrower agrees to pay and reimburse the General Administrative Agent for all of its reasonable out-of-pocket costs and expenses incurred in connection with the negotiation, preparation, execution, and delivery of this Amendment and Waiver, including the reasonable fees and expenses of counsel. 9. COUNTERPARTS. This Amendment and Waiver may be executed on any number of separate counterparts and all of said counterparts taken together shall be deemed to constitute one and the same instrument. 10. GOVERNING LAW. THIS AMENDMENT AND WAIVER SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK. 093110-0154-08480-NY03.2148011.3 IN WITNESS WHEREOF, the parties hereto have caused this Amendment and Waiver to be duly executed and delivered by their proper and duly authorized officers as of the day and year first above written. SAFETY-KLEEN SERVICES, INC. By: /s/ Larry W. Singleton -------------------------- Name: Larry W. Singleton Title: C.F.O. 1-14-02 093110-0154-08480-NY03.2148011.3 TORONTO DOMINION (TEXAS), INC., as General Administrative Agent, Underwriter and Lender By: ---------------------------------- Name: Title: THE TORONTO-DOMINION BANK, HOUSTON AGENCY as Issuing Lender By: ---------------------------------- Name: Title: 093110-0154-08480-NY03.2148011.3 THE CIT GROUP/BUSINESS CREDIT, INC., as Collateral Agent, Underwriter and Lender By: ---------------------------------- Name: Title: Signature Page to Amendment and Waiver 093110-0154-08480-NY03.2148011.3 GSCP RECOVERY, INC. By: ---------------------------------- Name: Title: Signature Page to Amendment and Waiver 093110-0154-08480-NY03.2148011.3 GSCP RECOVERY II, L.P. By: GSC Recovery II GP, L.P., its general partner By: GSC RII, LLC, its general partner By: GSCP (NJ) Holdings, L.P., its sole member By: GSCP (NJ), Inc., its general partner By: ---------------------------------- Name: Title: Signature Page to Amendment and Waiver 093110-0154-08480-NY03.2148011.3 BANK ONE, NA By: ---------------------------------- Name: Title: Signature Page to Amendment and Waiver 093110-0154-08480-NY03.2148011.3 GOLDMAN SACHS CREDIT PARTNERS, L.P. By: ---------------------------------- Name: Title: Signature Page to Amendment and Waiver 093110-0154-08480-NY03.2148011.3 SENIOR DEBT PORTFOLIO By Boston Management and Research, as Advisor By: ---------------------------------- Name: Title: Signature Page to Amendment and Waiver 093110-0154-08480-NY03.2148011.3