April 3, 1995


Jules Firetag
c/o Cruse, Firetag & Bock , P.C
5611 North 16th Street
Phoenix, Arizona   85016

Dear Mr. Firetag:

         I am happy to advise  you that you have been  selected  by the Board of
Directors (the "Board") of H.E.R.C.  Products  Incorporated (the "Company"),  to
receive  a  non-incentive  stock  option  and that on March 23,  1995,  you were
granted an option to  purchase  One  Hundred  Thousand  (100,000)  shares of the
Company's  Common  Stock,  $.01 par value (the  "Stock"),at a price of $2.50 per
share with respect to the first 50,000 shares of Stock,  and at a price of $4.00
per share with respect to the second 50,000 shares of Stock.  The option granted
to you is  subject to the terms and  conditions  set forth in this  letter  (the
"Agreement").

         The Board has imposed the following  terms and  conditions  relating to
your option and its exercise:

         1. You may exercise  your option in whole or in part from time to time,
only in accordance  with Paragraph 3 below,  by delivery to the Company (in care
of its Secretary) at the principal offices of the Company,  presently located at
3622 North 34th Avenue,  Phoenix,  Arizona 85017,  written irrevocable notice of
exercise in the form attached to this letter as Exhibit A. specifying the number
of shares of Stock with respect to which the option is being exercised, together
with  payment  of the  exercise  price for  those  shares of Stock in cash or by
check.  Any other form of  exercise  or tender  may be  refused by the  Company,
acting through the Board or otherwise, in its discretion.

         2. Your  option is not  transferable  other than by will or the laws of
descent and distribution and is exercisable,  during your lifetime, only by you.
You may not assign or otherwise transfer or encumber your option or any interest
in your option to any person in any way.

         3.       (a) Your  options  shall  vest on  December  1, 1995  provided
         you are still a Director  of the  Company at such time,  unless you are
         not re-elected to the Board.

                  (b)  Notwithstanding  any other  provision  of this  Agreement
         (other than  Paragraph  3(c)  below),  your  option,  to the extent not
         previously  exercised,  shall  automatically  terminate  and  be  of no
         further force or effect as to all remaining  shares of Stock as of five
         o'clock p.m., M.S.T., on December 1, 1999.

                  (c) In its sole discretion,  the Board may waive or accelerate
         vesting of options, or waive or extend expiration dates, other than the
         final expiration date.

         4. The Company will reserve or keep  available at all times  sufficient
shares of Stock to permit the  exercise  of your  option  and all other  options
granted or to be granted.

         5. It is contemplated that the Stock in the Company to be issued to you
upon exercise of your option will not be registered  under the Securities Act of
1933,  as amended (the "Act") or any  applicable  state  securities  laws, or in
reliance  on  exemptions  from  registration  thereunder.  If in the  opinion of
counsel  satisfactory  to the Company no  exemption  from  registration  is then
available,  or if such issuance is otherwise in violation of  applicable  law at
the time  purchase  rights are exercised  under this option,  then the Company's
obligation  to issue  shares of its Stock upon  exercise  of your  option  shall
terminate. If such an exemption is available in the opinion of such counsel, and
such  issuance is not  otherwise  in violation  of  applicable  law you (or your
personal representative(s),  devisee(s), or heir(s)) will deliver to the Company
as a condition precedent to giving notice of each exercise, an investment letter
agreement  in form and  substance  satisfactory  to the  Company  to enable  the
Company to comply  with the Act or other  applicable  securities  laws and which
may,  among other  things,  limit or condition the right to dispose of shares of
Stock  acquired by exercise of your option and will be permitted  only if in the
opinion of counsel  satisfactory  to the  Company,  such  disposition  is not in
violation  of the  Act,  any  applicable  state  securities  laws  or any  other
applicable law, regulation or rule, and you (or your personal representative(s),
devisee(s), or heirs(s)) deliver to the Company a letter agreement in form and

Jules Firetag
April 3, 1995
Page 2

substance  satisfactory  to the Company  whereby  your  successor(s)  or assigns
agrees to be bound by the terms and  conditions  of this  Paragraph  5. You (and
your personal representative(s), devisee(s), or heirs(s)) agree to pay all costs
of  obtaining  any legal  opinions  and all costs in  connection  with  proposed
exercise of your option or dispositions of shares of Stock acquired  pursuant to
your option.

         6. You agree to pay to the Company or to make arrangements satisfactory
to the Board to pay to the Company,  at such time as any income is recognized by
you with respect to this option, any Federal,  state, or local taxes of any kind
required by law to be withheld  on such income by the  Company.  In the event of
disposition  or other  transfer by you of Stock  issued to you upon  exercise of
your  options,  you agree to  provide to the  Company  promptly  written  notice
describing in reasonable  detail the disposition or transfer,  including without
limitation the sale price, if any, and date of transfer or disposition.

         7.  In  the  event  of  any  merger,   reorganization,   consolidation,
recapitalization,  dividend (other than a cash dividend),  stock split,  reverse
stock split, or other change in corporate  structure  affecting the Stock,  such
substitution  or  adjustment  shall be made in the number and exercise  price of
shares  of  Stock  subject  to  this  Agreement,  as  may  be  determined  to be
appropriate  by the Board in order to prevent  dilution or  enlargement  of your
rights under this Agreement, provided that the number of shares of Stock subject
to your award shall always be a whole number.

         8. This option  granted to you is governed by, and shall be interpreted
according to, the laws of the State of Arizona.

         9. Each  party  hereto  agrees to do all such  things and take all such
actions,  and to make, execute and deliver such other documents and instruments,
as shall be reasonably requested to carry out the provisions, intent and purpose
of this Agreement.

         This  letter  only  grants the  options  described  above and is not an
employment  agreement or a promise or assurance of continued  employment for any
period of time including any period of time necessary to permit full exercise of
the options under Paragraph 1 above.

         Please  acknowledge  your  receipt of this  letter,  together  with the
materials  referred to herein and your  agreement to the terms and conditions of
your option as set forth herein by signing the enclosed  copy of this letter and
returning  it promptly to the  Secretary of the Company at the address set forth
in Section 1 of this letter.  Any questions  concerning  any matter  relating to
your non-incentive stock option should also be addressed to the Secretary.

                                            Very truly yours,

                                            H.E.R.C. Products Incorporated





                                            By   /s/    Gary S. Glatter
                                                --------------------------------
                                            Its      President
                                                ----------------------------




ACCEPTED AND AGREED:


/s/  Jules Firetag
- -------------------------------
Jules Firetag
                                   EXHIBIT "A"

Jules Firetag
April 3, 1995
Page 3

                          NOTICE OF EXERCISE OF OPTION
              TO PURCHASE SHARES OF H.E.R.C. PRODUCTS INCORPORATED
                          AND RECORD OF STOCK TRANSFER

         I hereby  exercise my Stock Option  granted  pursuant to a letter dated
April 3, 1995 (the "Agreement") subject to all the terms and provisions referred
to in the  Agreement,  and notify you of my desire to  purchase  _______________
shares of Common Stock of H.E.R.C.  Products  Incorporated (the "Company") which
were offered to me pursuant to said  Option.  Enclosed is my check in the sum of
$______________ in full payment for such shares.

         I hereby  represent that the __________  shares of the Company's Common
Stock to be  delivered  to me  pursuant to the  above-mentioned  exercise of the
Option granted to me on March 23, 1995 are being acquired by me as an investment
and not with a view to, or for sale in connection  with, the distribution of any
such  shares.  I also  represent  that I have  read  and  fully  understand  the
Agreement,  including  without  limitation the  restrictions  on transfer of the
shares  hereby  being  acquired.  I  agree  to  indemnify  the  Company  and its
subsidiaries, together with their respective officers and directors, against any
and all liabilities, losses, damages and expenses (including reasonable attorney
fees) arising from or in connection  with any  disposition  of the shares hereby
being acquired,  or any interest therein, in violation of applicable  securities
laws or  regulations.  I further  represent that I have been given access to all
information  necessary to allow me to make a decision as to the  advisability of
an  investment in the  Company's  stock and the value of such stock,  and that I
have the skill and experience necessary to make such decision.

         DATED:_____________________________, 19 ___ .


       

                                            ____________________________________
                                            Jules Firetag





Receipt is hereby acknowledged of the delivery to me by _____________________ on
_______________  of stock  certificates  for  _______  shares  of  Common  Stock
purchased by me pursuant to the terms and  conditions of the Agreement  referred
to above, which shares were transferred to me on H.E.R.C.  Products Incorporated
stock record books on _______________, 19___.



                                            ____________________________________
                                            Jules Firetag