Page 21
                                                  EXHIBIT 1
                        CERTIFICATE OF SELLING SHAREHOLDER
        The undersigned selling shareholder ("Holder") has requested that
   RENTECH, INC. (the "Company"), include in a Registration Statement on
   Form S-3 certain shares of the Company's common stock (the "Securities")
   desired to be sold by the Holder.  To induce the Company to register such
   Securities for public sale by the Holder:
   
        1.  The Holder represents and warrants to and covenants with the
   Company that:  (i) the Holder has fully and accurately completed the
   Registration Statement Questionnaire for use by the Company in
   preparation of the Registration Statement and the answers and information
   contained therein are true and correct as of the date hereof and will be
   true and correct as of the effective date of the Registration Statement
   and at all times thereafter; (ii) the Holder understands that a current
   prospectus is required to be delivered to any purchaser of the
   Securities; (iii) the Holder has not entered into any agreement, written
   or oral, for the sale of any of the Securities upon terms different from
   those set forth in the Registration Statement; (iv) the Holder is aware
   of and agrees to abide by the provisions of Rule 10b-6 under the
   Securities Exchange Act of 1934 ("1934 Act"), which provides, in essence,
   that the Holder, under certain circumstances, may not bid for or purchase
   any of the Securities covered by the Registration Statement or any
   security of the same class, or any right to purchase any such security,
   and may not attempt to induce any person to purchase any such security or
   right until all Securities covered by such Registration Statement and
   owned by such Holder shall have been sold or withdrawn; and (v) the
   Holder is aware of and agrees to abide by the provisions of Rule 10b-7
   under the 1934 Act which provides that any person who offers to buy or
   buys the common stock of the Company for the purpose of maintaining or
   stabilizing the market price of such common stock to facilitate the sale
   of the Securities may be deemed to have violated rules prohibiting
   manipulation of market prices for securities.
  
        2.  The Holder agrees to promptly give notice to the Company in the
   event any of the information provided by the Holder in the Registration
   Statement Questionnaire or any of the information relating to the
   Securities owned by the Holder included in the Registration Statement,
   or to the plan of distribution as set forth in the Registration Statement
   (copies of which are enclosed), should become materially false or
   misleading.  The Holder acknowledges and agrees that there may
   occasionally be times when the Company must temporarily suspend the use
   of the prospectus and that the Holder will not be able to sell any of the
   Securities during the suspension period.
   
        3.  To the extent permitted by law, the Holder will indemnify and
   hold harmless the Company and its officers, directors and any person who
   controls the Company within the meaning of the Securities Act of 1933, as
   amended, for any claims, damages or liabilities (and actions related
   thereto) arising out of any untrue or alleged untrue statement of any
   material fact or based upon the omission or alleged omission to state a
   material fact required to be stated in the Registration Statement,
   prospectus or amendments or to make statements therein not misleading,
   but only to the extent that such untrue or alleged untrue statement or
   omission or alleged omission was made in reliance upon and in conformity
   with written information furnished by Holder for use in connection with
   such registration. 
   
        Dated this         day of                           , 1996.
                   -------        --------------------------
   
   ------------------------------      ------------------------------
   Signature                           Signature (if held jointly)
   
   ------------------------------      ------------------------------
   Print or Type Name                  Print or Type Name