<PAGE>
                                                      PAGE 14

                                                           Exhibit 4.2

  SECURITIES ISSUED UPON EXERCISE OF THIS OPTION HAVE NOT BEEN REGISTERED
  UNDER THE SECURITIES ACT OF 1933 ("THE ACT"), AND ARE "RESTRICTED
  SECURITIES" AS THAT TERM IS DEFINED IN RULE 144 UNDER THE ACT.  THE
  SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD OR OTHERWISE TRANSFERRED
  EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT OR
  PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE ACT, THE
  AVAILABILITY OF WHICH IS TO BE ESTABLISHED TO THE SATISFACTION OF THE
  COMPANY.


                                 RENTECH, INC.

                       INCENTIVE STOCK OPTION AGREEMENT



       THIS STOCK OPTION AGREEMENT, hereinafter referred to as the "Option"
  or the "Agreement," is entered into on --------------------, -----,
  between RENTECH, INC., a Colorado corporation ("the Company"), and -----
  ---------------------------------- ("the Optionee"), whose address is ---
  ------------------------------------------------------------------------.

       Pursuant to the terms of the Rentech, Inc. 1998 Stock Option Plan
  ("Plan"), the Company hereby grants an incentive stock option to purchase
  --------------- shares of common stock of the Company, $.01 par value per
  share ("Common Stock"), to the Optionee at the price and in all respects
  subject to the terms, definitions and provisions of the Agreement
  ("Option").

       1.  Option Price.  The option price is $-------- for each share,
  which is not less than the fair market value of the Company's stock on
  --------------------, --------, the date this Option was granted.  For
  purposes of this Agreement, the fair market value of such common stock
  shall be determined as follows:  (i) if the common stock is listed on a
  national securities exchange or admitted to unlisted trading privileges
  on such exchange, then the market value shall be the last reported sale
  price of the common stock on the composite tape of such exchange, or, if
  no such sale is made on any trading day, the average closing bid and
  asked prices for such day on the composite tape of such exchange; or (ii)
  if the common stock is not so listed or admitted to unlisted trading
  privileges, the market price shall be the average of the last reported
  bid and asked prices reported by the National  Association of Securities
  Dealers Quotation System (or if not quoted on NASDAQ, by the National
  Quotation Bureau, Inc. or other reporting medium); or (iii) otherwise the
  market price shall be an amount not less than book value determined in
  such reasonable manner as may be prescribed by the board of directors of
  the Company, such determination to be final and binding upon the
  Optionee.





  <PAGE>
                                                      PAGE 15


       2.  Option Period.  The option period during which this Option may
  be exercised shall be ----- years from date of this grant, expiring at
  12:00 o'clock p.m. on -----------------------, -------,. Denver time.
  The Option granted shall be void if not exercised during the option
  period.

       3.  Exercise of Option.  Unless the Option is terminated as provided
  pursuant to this Agreement, an Optionee may exercise this option for up
  to, but not in excess of, the amounts of shares subject to the Option.
  The Option may be exercised, in whole or in part, and at any time and
  from time to time within its term but it shall not be exercisable after
  the expiration of ----- years from the date on which it was granted.

       (a)  Right to Exercise.  Options shall be exercisable only during
  the option period by the Optionee:

            (i)  while the Optionee is in "continuous employment with the
  Company;" provided, however, if the Optionee's employment is terminated
  by Optionee for cause or by the Company without cause, the Optionee shall
  have a period of three months from the date Optionee's employment
  terminates in which to exercise the Option to the extent the Option was
  exercisable at the time of termination, but in no event later than the
  expiration of the option period.  If the Optionee should die during this
  three-month period, the Option may be exercised by the person or persons
  to whom the rights under the Option passed by will or the laws of descent
  and distribution to the same extent and during the same period the
  Optionee could have exercised the Option had Optionee not died.  In the
  event the Optionee should terminate employment by the Company without
  cause or the Company should terminate Optionee's employment with cause,
  then all unexercised Options granted to Optionee shall be forfeited and
  canceled effective upon such termination.  For purposes of this section,
  "continuous employment with the Company" shall mean the absence of any
  interruption or termination of employment by the Company.  Continuous
  employment shall not be considered interrupted in the case of transfer of
  the duties of the Optionee among the Company and any of its Subsidiary
  Corporations or during leave of absence for a company-approved purpose.

  Except as otherwise provided, the option period shall terminate upon the
  Optionee's termination of employment if that date is earlier than the
  term of the Option.

            (ii)  If the Optionee should die or become permanently totally
  disabled while employed by the Company, any Option or unexercised portion
  thereof, to the extent exercisable at the time of the Optionee's death or
  disability, may be exercised by Optionee, the Optionee's conservator or
  legal guardian or by the person or persons to whom the Optionee's rights
  under the Option passed by will or the laws of descent and distribution
  not later than twelve months after the Optionee's death or not later than
  twelve months after the Optionee's disability, but in no event later than
  the expiration of the option period.







  <PAGE>
                                                      PAGE 16

       (b)  Change in Control.  In the event that the Company or
  substantially all of its assets are sold or there is a change in control
  of the Company, as evidenced by a change of fifty percent (50%) or more
  in the ownership of the issued and outstanding shares of the Company's
  common stock or memberships on the Company's board of directors in any
  one transaction or series of related transactions, this Option shall,
  upon such occurrence, become exercisable in full, notwithstanding any
  other provisions of this Agreement to the contrary.

       (c)  Method of Exercise.  This Option shall be exercisable by a
  written notice delivered to the Company which shall:

            (i)  State the election to exercise the Option, the number of
  shares in respect of which it is being exercised (which must be in
  multiples of one hundred shares), the person in whose name the stock
  certificate or certificates for such shares of common stock is to be
  registered, with that person's address and Social Security number (or if
  more than one, the names, addresses and Social Security numbers of such
  persons);

            (ii)  Contain such representations and agreement as to the
  holder's investment intent with respect to such shares of Common Stock as
  may be satisfactory to the Company's counsel;

            (iii)  Be signed by the person or persons entitled to exercise
  the Option and, if the Option is being exercised by any person or persons
  other than the Optionee, be accompanied by proof, satisfactory to counsel
  for the Company, of the right of such person or persons to exercise the
  Option.

       Payment of the purchase price of any shares with respect to which
  the Option is being exercised shall be by cash or certified check,
  previously acquired shares of the Common Stock having a fair market value
  equal to the option price, or previously acquired shares of Common Stock
  having a fair market value less than the option price, plus cash or
  certified check for the balance of the option price, and shall be
  delivered with the notice of exercise.  The certificate or certificates
  for shares of Common Stock as to which the Option shall be exercised
  shall be registered in the name of the person or persons exercising the
  Option.

       (d)  Restrictions on Exercise.  As a condition to exercise of this
  Option, the Company may require the person exercising this Option to make
  any representation and warranty to the Company as may be required by any
  applicable law or regulation.

       (e)  $100,000 Limitation.  Notwithstanding anything to the contrary
  contained herein, the total fair market value (determined as of the date
  this Option was granted) of shares of stock with respect to which this
  Option shall become exercisable for the first time during any calendar
  year shall not exceed $100,000.  If in any calendar year shares of stock
  having a fair market value of more than $100,000 would become
  exercisable, but for the limitations of this section, this Option shall
  be exercisable only for shares having a fair market value not exceeding




  <PAGE>
                                                      PAGE 17

  $100,000, and this Option shall become exercisable with respect to any
  excess shares in the next succeeding calendar year, provided that the
  $100,000 limitation shall also be applied to such calendar year.  Subject
  to the term of this Option, such carryovers shall be made to succeeding
  calendar years, including carryovers of amounts from previous calendar
  years, without limitation.

       4.  Nontransferability of Option.  This Option may not be
  transferred in any manner and may be exercised during the lifetime of the
  Optionee only by the Optionee and after death of the Optionee by the
  person or persons to whom the Optionee's rights under the Option passed
  by will or the laws of descent and distribution.

       5.  Adjustments Upon Changes in Capitalization.  Whenever there is
  any change in the outstanding shares of Common Stock of the Corporation
  by reason of a stock dividend or split, recapitalization,
  reclassification, or other similar corporate change, the aggregate number
  of shares that can thereafter be purchased, and the option price per
  share, under each Option that has been previously granted and not
  exercised, and every number of shares used in determining whether a
  particular Option is grantable thereafter, shall be appropriately
  adjusted.  The adjustment shall be made by the Company's Board of
  Directors, and their determination shall be conclusive; provided,
  however, that fractional shares shall be rounded to the nearest whole
  share.  In any such case, the number and kind of shares that are subject
  to any Option (including any Option outstanding after termination of
  employment) and the option price per share shall be proportionately and
  appropriately adjusted without any change in the aggregate option price
  to be paid therefor upon exercise of the Option.

       6.  Notices.  Each notice relating to this Agreement shall be in
  writing and delivered in person or by certified mail to the proper
  address.  Each notice shall be deemed to have been given on the date it
  is received.  Each notice to the Company shall be addressed to it at its
  principal office, attention of the Secretary.  Each Optionee or other
  person or persons then entitled to exercise the Option shall be addressed
  to the Optionee or such other person or persons at the Optionee's address
  set forth in the heading of this Agreement.  Anyone to whom a notice may
  be given under this Agreement may designate a new address by notice to
  that effect.

       7.  Benefits of Agreement. This Agreement shall inure to the benefit
  of and be binding upon each successor of the Company.  All obligations
  imposed upon the Optionee and all rights granted to the Company under
  this Agreement shall be binding upon the Optionee's heirs, legal
  representatives and successors.  This Agreement shall be the sole and
  exclusive source of any and all rights which the Optionee, and heirs,
  legal representatives, or successors of Optionee may have in respect to
  the plan or any options or Common Stock granted or issued thereunder,
  whether to Optionee or any other person.

       8.  Incorporation of Plan.  This Agreement is made subject to the
  provisions of the Plan, the terms of which are incorporated herein by
  reference to the extent they apply to incentive stock options.





  <PAGE>
                                                      PAGE 18

  Capitalized terms used in the Plan shall have the same meaning, when used
  in this Agreement, as in the Plan.  In the event of conflict between
  provisions of the Plan and provisions of this Agreement, the provisions
  of the Plan shall control.

       9.  Resolution of Disputes.  Any dispute or disagreement which
  should arise under, or as a result of, or in any way relate to, the
  interpretation, construction or applicability of this Agreement will be
  determined by the stock option committee appointed by the by the Board of
  Directors of the Company.  Any such determination made by the Committee
  shall be final, binding, and conclusive for all purposes.

       10.  Approval of Stockholders.  If an option is granted by this
  Agreement prior to approval of the stockholders of the Plan, the option
  granted shall be null and void unless stockholder approval is obtained
  within twelve months after the Plan was adopted.

       11.  Investment Representation; Legend.  Optionee represents and
  agrees that all shares of Common Stock purchased by Optionee under this
  Agreement will be purchased for investment purposes only and not with a
  view to distribution or resale.  The Company may require that an
  appropriate legend be inscribed on the face of any certificate issued
  under this Agreement, indicating that transfer of the shares is
  restricted, and may place an appropriate stop transfer order with the
  Company's transfer agent with respect to such shares.

       12.  No Guarantee.  This Agreement shall in no way restrict the
  right of the Company to terminate Optionee's relationship with it,
  whether as an Employee or Consultant.

       IN WITNESS WHEREOF, the Company and the Optionee have caused this
  Agreement to be executed as of the day, month and year first above
  written.

  OPTIONEE:                         RENTECH, INC.



  ------------------------     By:  ------------------------------
                                    Dennis L. Yakobson, President



















  <PAGE>
                                                      PAGE 19

                                RENTECH, INC.

                  NOTICE OF EXERCISE OF STOCK OPTION ISSUED


  To:  Stock Option Committee
       Rentech, Inc.

       I hereby exercise my Option dated --------------------- to purchase
  --------------- shares of $.01 par value common stock of the Company at
  the option exercise price of $---------- per share.  Enclosed is a
  certified or cashier's check in the total amount of $----------, or
  payment in such other form as the Company has specified and agreed to
  accept, which is described at the bottom of this notice.

       I represent to you that I am acquiring said shares for investment
  purposes and not with a view to any distribution thereof.  I understand
  that my stock certificate may bear an appropriate legend restricting the
  transfer of my shares and that a stop transfer order may be placed with
  the Company's transfer agent with respect to such shares.

       I request that my shares be issued in the name of:


       -------------------------------------------------------------
                (Print your name in the form in which you wish
                        to have the shares registered)

       -------------------------------------------------------------
                          (Social Security Number)

       -------------------------------------------------------------
                             (Street and Number)

       -------------------------------------------------------------

       (City)                     (State)                 (Zip Code)

  Dated: ---------------, 20--


                        Signature:  -------------------------------