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                                                                    EXHIBIT 10.8




                    FOURTH AMENDMENT TO EMPLOYMENT AGREEMENT


         THIS FOURTH AMENDMENT TO EMPLOYMENT AGREEMENT is entered into as of
the  9th day of April, 1998 by and between HydroChem Holding, Inc., a Delaware
corporation (the "Employer"), and B. Tom Carter, Jr., an individual (the
"Employee").

                                    RECITALS

A.       Employer and Employee entered into a certain Employment Agreement as
         of December 15, 1995, which as amended by First, Second, and Third
         Amendments thereto dated as of January 10, 1995, March 20, 1995, and
         December 9, 1996, respectively, provides the terms of employment of
         Employee by Employer (the "Employment Agreement").

B.       Employer and Employee desire to further amend the Employment Agreement
         as hereinafter provided.

                                   AGREEMENT

         NOW, THEREFORE, in consideration of the premises and other good and
valuable consideration, the receipt and sufficiency of which is acknowledged,
the parties hereto agree as follows:

1.       Section 2 of the Employment Agreement is hereby amended by deleting
         the same in its entirety and substituting the following in lieu
         thereof:

                 "Except as otherwise provided herein, the "Period of
         Employment" shall be the period of time commencing on the date hereof
         and continuing until the date one year after either party gives the
         other party notice to terminate the Employment Agreement."

2.       Section 6 of the Employment Agreement is hereby amended by adding a
         subsection (f) as follows:

                 "(f) Reimbursement for Tax Assistance.

                 Effective as of January 1, 1998, Employer shall, upon receipt
                 of adequate supporting documentation, reimburse Employee up to
                 a maximum of Seven Thousand Dollars ($7,000) per year for fees
                 paid by Employee for professional tax services including
                 preparation of personal tax returns and personal tax advice."


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                                                                    EXHIBIT 10.9


         IN WITNESS WHEREOF, the parties have duly executed this Fourth
Amendment as of the year and date first above written.



                                 HYDROCHEM HOLDING, INC.
                              
                                 By: /s/ PELHAM H. A. SMITH
                                   --------------------------------------
                                       Pelham H. A. Smith, Vice President
                              
                              
                                 EMPLOYEE
                                 /s/ B. TOM CARTER, JR.                     
                                 ---------------------------------------- 
                                 B. Tom Carter, Jr. an individual
                              
                              
                 In consideration of the premises and other good and valuable
consideration, the undersigned hereby unconditionally guarantees the punctual
performance by HydroChem Holding, Inc., of all its duties and obligations under
the terms of this Fourth Amendment to Employment Agreement.

                                  HYDROCHEM INDUSTRIAL SERVICES, INC.
                                  
                                  
                                  By: /s/ PELHAM H. A. SMITH
                                     ------------------------------------
                                       Pelham H. A. Smith, Vice President
                                  

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