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                                                                EXHIBIT 10.31

                            [GELMAN SCIENCES LOGO]


                      NON-QUALIFIED STOCK OPTION AGREEMENT


TO:    Kim A. Davis

FROM:  Charles Gelman

DATE:  August 21, 1996


     The Board of Directors, the Corporation hereby grants you an option (the
"Option") to purchase 45,000 shares of the Common Stock, $.10 par value, of the
Corporation (the "Shares") at $27.000 per share, upon the terms and conditions
contained in this Agreement.

1.   The Option is intended to be an option which does not qualify as an
     incentive stock option within the meaning of the Internal Revenue Code of
     1986, as amended.

2.   The Option may not be transferred by you otherwise than by will or by the
     laws of descent and distribution and, during your lifetime, the Option is
     exercisable only by you.

3.   Subject to the terms contained in this Agreement, you may exercise the
     Option in accordance with the following schedule:

            5,000 shares will be exercisable on May 1, 1997
           10,000 shares will be exercisable on May 1, 1998
           15,000 shares will be exercisable on May 1, 1999
           10,000 shares will be exercisable on May 1, 2000
            5,000 shares will be exercisable on May 1, 2001

4.   In the event of a change in control of the Corporation, the right to
     exercise all options shall vest immediately upon such change.  For
     purposes of this provision, "change in control" means any of the
     following:  (1) the acquisition of beneficial ownership by any person or
     entity (or more than one (1) person or entity acting as a group) of a
     majority of the outstanding voting shares of the Corporation; (2) a tender
     offer made and consummated for at least thirty-three percent (33%) of
     Corporation's common stock; (3) the acquisition or beneficial ownership by
     any person or entity (or more than one (1) person or entity acting as a
     group) of more than fifty-one percent (51%) of the total fair market value
     of the Corporation's assets; or (4) a majority of the members of the Board
     are replaced within a one (1) year period.

5.   This Option will expire (to the extent not previously exercised) on the
     tenth anniversary of the date of this Agreement, unless terminated earlier
     upon your termination of employment with the Corporation or any subsidiary
     or your death, which are governed by Paragraphs 5 and 6 of this Agreement,
     respectively.

6.   If your employment with the Corporation or any subsidiary of the
     Corporation terminates for any reason other than your death, you have the
     right for a period of 90 days following such termination, but in no event
     subsequent to the expiration date of the Option, to 


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     exercise that portion of the Option, if any, which is exercisable by
     you on the date of termination of your employment.

7.   If your employment with the Corporation or any subsidiary of the
     Corporation terminates by reason of your death, the Option, to the extent
     it is exercisable on the date of your death, may be exercised for a period
     of 180 days following your death, but in no event subsequent to the
     expiration date of the Option, by your legal representative or by the
     person or persons to whom your rights shall pass by will or by the laws of
     descent and distribution.

8.   The Option shall be exercised by giving a written notice to the Secretary
     of the Corporation.  Such notice shall specify the number of Shares to be
     purchased, the name in which you desire to have the shares registered,
     your address and your social security number and shall be accompanied by
     payment in full in cash, or, with the consent of the Corporation's Board
     of Directors, in Common Stock of the Corporation, of the aggregate option
     price for the number of Shares purchased.  Such exercise shall be
     effective only upon the actual receipt of such written notice and no
     rights or privileges of a shareholder of the Corporation in respect of any
     of the Shares issuable upon exercise of any part of the Option shall inure
     to you or any other person who is entitled to exercise the Option unless
     and until certificates representing such Shares shall have been issued.

9.   Nothing contained in this Agreement, nor any action taken by the
     Corporation, shall confer upon you any right with respect to continuation
     of your employment by the Corporation or any subsidiary of the
     Corporation.

10.  If, upon or as a result of your exercise of the Option, there shall be
     payable by the Corporation any amount for income tax withholding, you will
     pay such amount to the Corporation to reimburse the Corporation for such
     income tax withholding.

11.  By agreeing to and accepting this agreement, you agree that the option
     previously granted to you on May 1, 1996, by the Compensation Committee of
     the Board of Directors of the Corporation, is hereby rescinded and
     cancelled, and the option spoken of in this agreement is in lieu thereof.

                                        Sincerely yours,
                                        GELMAN SCIENCES INC.

                        

                                        /s/ Charles Gelman
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                                        Charles Gelman
                                        Chairman of the Board

The above is agreed to and accepted:


/s/ Kim A. Davis
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Dated: August 21, 1996
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