AMENDMENT NO. 2 TO EMPLOYMENT AGREEMENT


                  Amendment No. 2 to Employment Agreement, effective as of March
28,  1997,  by and between  Gary S. Glatter  ("Glatter")  and H.E.R.C.  Products
Incorporated ("Corporation").

                  WHEREAS,   Glatter  and  the   Corporation   entered  into  an
Employment  Agreement  dated as of  January 1,  1994,  as  amended  ("Employment
Agreement"); and

                  WHEREAS, Glatter and the Corporation wish to further amend the
Employment  Agreement  to provide for the terms of the  severance  of  Glatter's
employment.

                  NOW,  THEREFORE,  in  consideration of the covenants set forth
herein, it is agreed:

                  1.  Through  June 30,  1997,  all the terms of the  Employment
Agreement, prior to this Amendment, shall remain in full force and effect.

                  2. As compensation after June 30, 1997, in substitution of the
provisions  of Sections  3.1 (Base  Salary)  and 3.2  (Bonus) of the  Employment
Agreement, the Corporation will pay Glatter the following amounts:

                           (a)  On  the  first  day  of  each  month,  from  and
including  July 1, 1997  through  December 31, 1997,  the  Corporation  will pay
Glatter $7,500; and

                           (b)  On  the  first  day  of  each  month,  from  and
including  January 1, 1998 through  December 31, 1998, the Corporation  will pay
Glatter $5,000.

                  3. In substitution of the provisions of Section 3.3 (Benefits)
after June 30,  1997,  the  Corporation  will  provide  Glatter with his current
family medical and dental  insurance  coverage in the manner  provided under the
COBRA rules and regulations after June 30, 1997 through December 31, 1998.

                  4.  Section  3.5  of the  Employment  Agreement  shall  remain
operative through October 31, 1997. In addition, Glatter shall have the right to
purchase on or before  November 1, 1997 from the  Corporation  the 1995 WindStar
Van which he is currently  using and all its  accessories  at the lesser of book
value on the books of the  Corporation or dealer  wholesale "blue book" value on
the date of purchase.

                  5.  Section 4 is amended as  provided in the  separate  Option
Agreement, as amended.

                  6.  Section  5 is  amended  to  provide  that the  term  shall
continue through June 30, 1997.

                  7.  Section 8 is  amended  to provide  that  Glatter  shall be
deemed to have  resigned as a director  and officer of the  Corporation  and any
subsidiary or affiliate of the Corporation on June 30, 1997.
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                  8.  Sections  1,  2,  3.4,  3.6,  6  and 7 of  the  Employment
Agreement  shall  cease to be  operative  on and after July 1,  1997.  Except as
modified in this  Amendment,  all the other terms of the  Employment  Agreement,
including,  but not limited to, Sections 3.8 and 9 thereof, shall remain in full
force and effect after June 30, 1997.

                  9. Terms not otherwise  defined in this  Amendment  shall have
the meanings assigned to them in the Option Agreement.

                                      H.E.R.C. PRODUCTS INCORPORATED



                                      By:  /s/ S. Steven Carl
                                         ---------------------------------------
                                         S. Steven Carl, Chief Executive Officer


                                      /s/ Gary S. Glatter
                                      ------------------------------------------
                                                   GARY S. GLATTER
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