Neither this Option nor the Common Stock to issued upon exercise hereof has been
registered under the Securities Act of 1933 (the "Act"),  or qualified under any
state securities law (the "Law"), and this Option has been, and the Common Stock
to be issued upon exercise  hereof will be, acquired for investment and not with
a view to, or for resale in connection with, any distribution  thereof.  No such
sale  or  other  disposition  may be  made  without  an  effective  registration
statement  under the Act and  qualification  under the law related thereto or an
opinion of counsel reasonably  satisfactory to Tech  Laboratories,  Inc. and its
counsel,  that said registration and  qualifications  are not required under the
Act and Law, respectively.

                             TECH LABORATORIES, INC.

                             STOCK OPTION AGREEMENT

     This stock  option  (the  "Option"  or the  "Agreement")  is being  granted
pursuant to that  certain  consulting  agreement  dated March 10,  1999,  by and
between Tech  Laboratories,  Inc.  (the  "Company")  and Mint  Corporation  (the
"Optionee").

I.   NOTICE OF STOCK OPTION GRANT

     The  Optionee is being  granted an Option to purchase  Common  Stock of the
Company. This Option shall be subject to the following terms and conditions:

Date of Grant:               July 10, 1999

Exercise Price:              $1.75 per share

Number of Shares Granted:    100,000

Type of Option:              Nonstatutory Stock Option

Expiration Date:             July 10, 2001, except as otherwise provided in this
                             Agreement.

II.  AGREEMENT

     1. GRANT OF OPTION. The Company hereby grants to the Optionee the Option to
purchase the number of shares  ("Shares")  set forth in the Notice of Grant,  at
the  Exercise  Price per share set forth in the Notice of Grant,  subject to the
terms and conditions set forth herein.

     2. EXERCISE OF OPTION.

          (a) Right of Exercise.  This Option may be  exercised,  in whole or in
     part,  subject  to the  terms of this  Agreement,  at any time from time to
     time, after the Date of Grant and prior to the Expiration Date.

          (b) Method of Exercise.  This Option is  exercisable by delivery of an
     exercise notice, in the form attached as Exhibit A (the "Exercise Notice"),
     which shall state the election to exercise the Option, the number of Shares
     in respect of which the Option is being exercised (the "Exercised Shares"),
     and such other  representations  and  agreements  as may be required by the
     Company.  The Exercise  Notice shall be signed by the Optionee and shall be
     delivered in person or by certified  mail to the  Secretary of the Company.
     The  Exercise  Notice  shall be  accompanied  by payment  of the  aggregate
     Exercise Price as to all Exercised Shares. This Option shall be







     deemed to be exercised  upon receipt by the Company of such fully  executed
     Exercise Notice accompanied by such aggregate Exercise Price.

     3. METHOD OF PAYMENT.  Payment of the aggregate  Exercise Price shall be by
any of the following, or a combination thereof, at the election of the Optionee:

          (a) Cash; or

          (b) Check.

     4. REGISTRATION UNDER THE SECURITIES ACT.

          (a)  "Piggyback  Registration".  If the  Company  shall  determine  to
     proceed with the actual preparation and filing of a registration  statement
     under the Securities Act in connection  with the proposed offer and sale of
     any of its  securities  by it or any of its security  holders in an initial
     public offering or otherwise  (other than a registration  statement on Form
     S-4 or S-8 or an offering  statement  on Form 1-A),  then the Company  will
     give  written  notice of its  determination  to all  record  holders of the
     Option and/or any Shares, as the case may be. Upon the written request from
     any  record  holder  or  holders  of an  aggregate  of more than 50% of the
     Options  and  Shares,  considered  in the  aggregate,  within 20 days after
     receipt of any such notice from the Company,  the Company  will,  except as
     herein provided,  cause all such Shares to be included in such registration
     statement,  all to the  extent  requisite  to  permit  the  sale  or  other
     disposition  by the  prospective  seller or  sellers of the Shares to be so
     registered;  provided,  further,  that  nothing  herein  shall  prevent the
     Company from, at any time, abandoning or delaying any registration.  If any
     registration  pursuant to this Section 4(a) shall be  underwritten in whole
     or in part,  the  Company  will  require  that  the  Shares  requested  for
     inclusion  pursuant to this Section 4(a) be included in the underwriting on
     the same  terms and  conditions  as the  securities  otherwise  being  sold
     through  the  underwriters.  In the event  that the  Shares  requested  for
     inclusion  pursuant to this  Section  4(a)  together  with any other shares
     which have similar piggyback registration rights (such other shares and the
     Shares being  collectively  referred to as the "Requested Stock") would, in
     the  sole  discretion  of the  managing  underwriter,  interfere  with  the
     successful  marketing of the shares of stock  offered by the  Company,  the
     number  of  shares of  Requested  Stock  otherwise  to be  included  in the
     underwritten  public offering may be reduced pro rata (by number of shares)
     among the holders thereof requesting such registration or excluded in their
     entirety  if so  required  by the  underwriter.  To the  extent  all or any
     portion of the  Requested  Stock is excluded from the  underwritten  public
     offering,  those shares of Requested Stock which are thus excluded from the
     underwritten  public  offering  shall be  withheld  from the  market by the
     holders  thereof for a period,  not to exceed 120 days,  which the managing
     underwriter  reasonably  determines  is  necessary  in order to effect  the
     underwritten public offering;  provided,  however, that the Shares included
     in  such   Requested   Stock  shall  be  included  in  the  Company's  next
     registration  statement,  subject to the earlier  registration  pursuant to
     Section 4(b).

          The obligation of the Company under this Section 4(a) shall be limited
     to one subsequent  registration  statement and shall not apply in the event
     and for so long as the  Company  has an  effective  registration  statement
     including a current prospectus pursuant to Section 4(b) hereof.

          (b)  Mandatory  Registration.  In the  event  the  undersigned  or its
     transferees  have not had  included in the  registration  statement  all of
     their Shares in connection with the Company's initial public offering, then
     the Company shall effect the  registration of all remaining  Shares as soon
     as  practicable,  but not later than 180 days after the  effective  date of
     such initial public offering;  provided,  however,  that such period may be
     extended or delayed by the Company for


                                       -2-





     one  period  up to 90 days if,  upon  advice  of  counsel  at the time such
     registration  statement is required to filed, or at the time the Company is
     required to exercise best efforts to cause such  registration  statement to
     become effective,  such delay is advisable and in the best interests of the
     Company because of the existence of non-public material information,  or to
     allow the Company to complete any pending audit of its financial statement,
     or any  non-routine  transaction,  such  as a  merger,  reorganization,  or
     acquisition,  which would  require  the filing of a Current  Report on Form
     8-K.

          (c) Registration  Procedures.  If and whenever the Company is required
     by the  provisions  of Section 4(a) or 4(b) to effect the  registration  of
     Registrable Securities under the Securities Act, the Company will:

               i) prepare and file with the SEC a  registration  statement  with
          respect  to such  securities,  and use its best  efforts to cause such
          registration statement to become and remain effective until the Shares
          are freely salable without the volume limitations of Rule 144;

               ii)  prepare  and  file  with  the SEC  such  amendments  to such
          registration  statement and  supplements to the  prospectus  contained
          therein  as may be  necessary  to  keep  such  registration  statement
          effective  until the  Shares are freely  saleable  without  the volume
          limitations of Rule 144;

               iii)  furnish  to the  security  holders  participating  in  such
          registration   and  to  the   underwriters  of  the  securities  being
          registered  such  reasonable  number  of  copies  of the  registration
          statement,  preliminary  prospectus,  final  prospectus and such other
          documents  as such  underwriters  may  reasonably  request in order to
          facilitate the public offering of such securities;

               iv) use its best  efforts to register  or qualify the  securities
          covered by such registration  statement under such state securities or
          blue sky laws of such jurisdictions as such participating  holders may
          reasonably  request in writing  within 20 days  following the original
          filing of such registration  statement,  except that the Company shall
          not for any  purpose  be  required  to  execute a general  consent  to
          service  of  process  or  to  qualify  to  do  business  as a  foreign
          corporation in any jurisdiction wherein it is not so qualified;

               v)  notify   the   holders  of  Shares   participating   in  such
          registration,  promptly after it shall receive notice thereof,  of the
          time  when such  registration  statement  has  become  effective  or a
          supplement  to any  prospectus  forming  a part of  such  registration
          statement has been filed;

               vi) notify  such  holders  promptly of any request by the SEC for
          the  amending  or  supplementing  of such  registration  statement  or
          prospectus or for additional information;

               vii) prepare and file with the SEC,  promptly upon the request of
          any such holders,  any amendments or supplements to such  registration
          statement  or  prospectus  which,  in the  opinion of counsel for such
          holders  (and  concurred in by counsel for the  Company),  is required
          under the  Securities Act or the rules and  regulations  thereunder in
          connection with the distribution of Common Stock by such holder;

               viii) prepare and promptly file with the SEC and promptly  notify
          such  holders of the filing of such  amendment or  supplement  to such
          registration  statement or  prospectus  as may be necessary to correct
          any statements or omissions if, at the time when a prospectus relating
          to such  securities is required to be delivered  under the  Securities
          Act, any event shall have


                                       -3-





          occurred  as the  result  of which  any such  prospectus  or any other
          prospectus  as then in effect would  include an untrue  statement of a
          material fact or omit to state any material fact necessary to make the
          statements  therein,  in the light of the  circumstances in which they
          were made, not misleading; and

               ix) advise such holders,  promptly  after it shall receive notice
          or obtain knowledge thereof,  of the issuance of any stop order by the
          SEC suspending the effectiveness of such registration statement or the
          initiation  or  threatening  of any  proceeding  for that  purpose and
          promptly  use its best  efforts to prevent  the  issuance  of any stop
          order or to obtain its withdrawal if such stop order should be issued.

          (d) Expenses.

               i) With respect to the registration  required pursuant to Section
          4(a) or 4(b) hereof, all fees, costs and expenses of and incidental to
          such  registration,  inclusion  and public  offering (as  specified in
          paragraph  (ii) below) in connection  therewith  shall be borne by the
          Company, provided, however, that any securityholders  participating in
          such registration  shall bear their pro rata share of the underwriting
          discount and commissions and transfer taxes.

               ii) The fees,  costs and expenses of  registration to be borne by
          the Company as provided in paragraph (i) above shall include,  without
          limitation,   all  registration,   filing,  and  NASD  fees,  printing
          expenses,  fees and  disbursements  of counsel and accountants for the
          Company,  and all legal fees and  disbursements  and other expenses of
          complying with state securities or blue sky laws of any  jurisdictions
          in  which  the  securities  to be  offered  are to be  registered  and
          qualified (except as provided in (i) above). Fees and disbursements of
          counsel and accountants for the selling  securityholders and any other
          expenses  incurred  by  the  selling   securityholders  not  expressly
          included above shall be borne by the selling securityholders.

          (e) Indemnification.

               i) The Company will  indemnify  and hold  harmless each holder of
          Shares which are included in a registration  statement pursuant to the
          provisions of Section 4(a) or 4(b) hereof, its directors and officers,
          and any underwriter (as defined in the Securities Act) for such holder
          and each person,  if any, who controls such holder or such underwriter
          within the meaning of the Securities  Act, from and against,  and will
          reimburse such holder and each such underwriter and controlling person
          with respect to, any and all loss, damage, liability, cost and expense
          to which such holder or any such underwriter or controlling person may
          become subject under the Securities Act or otherwise,  insofar as such
          losses,  damages,  liabilities,  costs or  expenses  are caused by any
          untrue  statement or alleged  untrue  statement  of any material  fact
          contained in such  registration  statement,  any prospectus  contained
          therein or any amendment or supplement thereto, or arise out of or are
          based  upon the  omission  or  alleged  omission  to state  therein  a
          material fact  required to be stated  therein or necessary to make the
          statements  therein,  in light of the circumstances in which they were
          made, not misleading;  provided, however, that the Company will not be
          liable  in any such case to the  extent  that any such  loss,  damage,
          liability,  cost or expenses  arises out of or is based upon an untrue
          statement or alleged untrue  statement or omission or alleged omission
          so made in conformity with information  furnished by such holder, such
          underwriter or such controlling person in writing specifically for use
          in the preparation thereof.

               ii) Each holder of Shares included in a registration  pursuant to
          the  provisions of Section 4(a) or 4(b) hereof will indemnify and hold
          harmless the Company, its directors and


                                       -4-





          officers, any controlling person and any underwriter from and against,
          and will  reimburse  the Company,  its  directors  and  officers,  any
          controlling  person and any  underwriter  with respect to, any and all
          loss, damage,  liability,  cost or expense to which the Company or any
          controlling person and/or any underwriter may become subject under the
          Securities  Act  or  otherwise,   insofar  as  such  losses,  damages,
          liabilities,  costs or expenses are caused by any untrue  statement or
          alleged  untrue  statement  of any  material  fact  contained  in such
          registration  statement,  any  prospectus  contained  therein  or  any
          amendment or supplement thereto, or arise out of or are based upon the
          omission or alleged omission to state therein a material fact required
          to be stated therein or necessary to make the statements  therein,  in
          light of the circumstances in which they were made, not misleading, in
          each case to the  extent,  but only to the  extent,  that such  untrue
          statement or alleged untrue  statement or omission or alleged omission
          was so made in reliance  upon and in strict  conformity  with  written
          information  furnished by or on behalf of such holder specifically for
          use in the preparation thereof.

               iii) Promptly after receipt by an  indemnified  party pursuant to
          the provisions of paragraph (i) or (ii) of this Section 4(e) of notice
          of the  commencement of any action involving the subject matter of the
          foregoing indemnity provisions such indemnified party will, if a claim
          thereof is to be made against the  indemnifying  party pursuant to the
          provisions  of  said  paragraph  (i)  or  (ii),  promptly  notify  the
          indemnifying party of the commencement thereof; but the omission to so
          notify the  indemnifying  party will not relieve it from any liability
          which it may have to any  indemnified  party otherwise than hereunder.
          In case such action is brought  against any  indemnified  party and it
          notifies  the  indemnifying  party of the  commencement  thereof,  the
          indemnifying party shall have the right to participate in, and, to the
          extent that it may wish,  jointly  with any other  indemnifying  party
          similarly  notified,  to assume  the  defense  thereof,  with  counsel
          satisfactory to such  indemnified  party,  provided,  however,  if the
          defendants in any action  include both the  indemnified  party and the
          indemnifying  party and the  indemnified  party shall have  reasonably
          concluded  that  there may be legal  defenses  available  to it and/or
          other  indemnified  parties which are different from or in addition to
          those available to the indemnified party, or if there is a conflict of
          interest which would prevent counsel for the  indemnifying  party from
          also  representing  the indemnified  party,  the indemnified  party or
          parties have the right to select  separate  counsel to  participate in
          the  defense  of such  action on behalf of such  indemnified  party or
          parties.  After notice from the indemnifying party to such indemnified
          party  of  its  election  so  to  assume  the  defense  thereof,   the
          indemnifying  party  will  not be  liable  to such  indemnified  party
          pursuant to the provisions of said paragraph (i) or (ii) for any legal
          or other expense  subsequently  incurred by such indemnified  party in
          connection  with the defense  thereof other than  reasonable  costs of
          investigation,  unless (1) the  indemnified  party shall have employed
          counsel in accordance  with the provisions of the preceding  sentence,
          (2)  the   indemnifying   party  shall  not  have   employed   counsel
          satisfactory  to the  indemnified  party to represent the  indemnified
          party within a reasonable time after the notice of the commencement of
          the  action  or  (iii)  the  indemnifying  party  has  authorized  the
          employment of counsel for the indemnified  party at the expense of the
          indemnifying party.

     5.  TRANSFERABILITY  OF  OPTION.  This  Option may only be  transferred  in
compliance  with the Act.  The  Company may  request in its sole  discretion  an
opinion of counsel from the transferor  prior to any transfer to the effect that
the  Option  may be  transferred  by the  transferor  without  violation  of the
registration  provision of the Act.  Transferor  shall notify the Company of any
proposed  transfer.  The  terms  of this  Agreement  shall be  binding  upon the
executors, administrators, heirs, successors, and assigns of the Optionee.



                                       -5-





     6. TERM OF OPTION.  This Option may be  exercised  only within the term set
out in the  Notice  of  Grant,  and may be  exercised  during  such term only in
accordance with the terms of this Option Agreement.

     7.  TERMINATION  OF OPTION.  The Option shall  terminate on the  Expiration
Date; provided,  however,  that if the Company files any registration  statement
(other than a registration statement on Form S-4 or S-8) on or prior to July 10,
2010, the Expiration Date shall be a date that is (i) if the Shares are included
in  that  registration  statement,  90 days  after  the  effective  date of that
registration  statement,  or  (ii)  if the  Shares  are  not  included  in  that
registration  statement,  90 days after the effective  date of the  registration
statement in which the Shares are included in accordance  with the last sentence
of Section 4(a) or with Section 4(b).

     8. DILUTION PROTECTION.

          (a) In the  event the  Company  shall (i)  declare a  dividend  on its
     Common Stock in shares of Common Stock or make a distribution  in shares of
     Common  Stock,  (ii)  declare a stock  split or reverse  stock split of its
     outstanding shares of Common Stock, (iii) combine its outstanding shares of
     Common Stock into a smaller number of shares of Common Stock, or (iv) issue
     by  reclassification  of  its  shares  of  Common  Stock  other  securities
     (including any such  reclassification in connection with a consolidation or
     merger in which the Company or any of its  subsidiaries  is the  continuing
     corporation),  then the  number of shares of Common  Stock of the  Company,
     deliverable  to the  Optionee  hereunder  and the  exercise  price  related
     thereto shall be adjusted so that the Optionee shall be entitled to receive
     the kind and  number of shares of  Common  Stock of the  Company  which the
     Optionee has the right to receive,  upon the happening of any of the events
     described above, with respect to the shares of the Company stock which were
     otherwise  deliverable pursuant herein. An adjustment made pursuant to this
     paragraph shall become  effective  immediately  after the effective date of
     such event;

          (b) Whenever the number of Shares or the exercise price of this Option
     is adjusted pursuant to this paragraph,  the Company shall promptly mail by
     first  class  mail,  postage  prepaid,  to the  Optionee,  notice  of  such
     adjustment or adjustments.

     9.  AVAILABILITY OF COMPANY STOCK.  The Company hereby agrees and covenants
that at all times  during the  Exercise  Period it shall  reserve for issuance a
sufficient  number  of shares of  common  stock as would be  required  upon full
exercise of the rights represented by this Agreement.

     10. NO RIGHT TO EMPLOYMENT.  Nothing in this  Agreement  shall be deemed to
create a relationship of employer to employee. The Company granted the Option to
Optionee in consideration of the performance of certain  consulting  services by
Optionee.

     11. TAX CONSEQUENCES. Some of the federal tax consequences relating to this
Option,  as of the date of this  Option,  are set forth  below.  THIS SUMMARY IS
NECESSARILY INCOMPLETE,  AND THE TAX LAWS AND REGULATIONS ARE SUBJECT TO CHANGE.
THE  OPTIONEE  SHOULD  CONSULT A TAX ADVISER  BEFORE  EXERCISING  THIS OPTION OR
DISPOSING OF THE SHARES.

          (a)  Exercising  the Option.  The Optionee may incur  regular  federal
     income tax  liability  upon  exercise of the Option.  The Optionee  will be
     treated as having received  compensation income (taxable at ordinary income
     tax rates)  equal to the excess,  if any,  of the Fair Market  Value of the
     Exercised  Shares on the date of  exercise  over their  aggregate  Exercise
     Price.  If the  Optionee  is deemed for any reason to be an  employee,  the
     Company will be


                                       -6-





     required  to  withhold  from his or her  compensation  or collect  from the
     Optionee and pay to the applicable taxing  authorities an amount equal to a
     percentage of this compensation income at the time of exercise.

          (b) Disposition of Shares. If the Optionee holds Shares for at least a
     year,  any gain  realized on  disposition  of the Shares will be treated as
     long-term capital gain for federal income tax purposes.

     12.  GOVERNING  LAW. This Agreement is governed by the laws of the State of
New York.

     IN WITNESS WHEREOF, this Agreement is executed this day of April, 1999.


                                        TECH LABORATORIES, INC.



                                        By:
                                           -------------------------------------


                                        OPTIONEE:

                                        MINT CORPORATION



                                        By:
                                           -------------------------------------
                                           Richard Kandel, President


                                       -7-




                             TECH LABORATORIES, INC.

                                 EXERCISE NOTICE

Tech Laboratories, Inc.
955 Belmont Avenue
North Haledon, New Jersey 07508

     1. EXERCISE OF OPTION.  Effective as of today,  _____________,  199___, the
undersigned  ("Purchaser")  hereby  elects to purchase  ___________  shares (the
"Shares") of the Common Stock of Tech  Laboratories,  Inc. (the "Company") under
and pursuant to the Stock Option  Agreement  dated April ____, 1999 (the "Option
Agreement").  The  purchase  price for the  Shares  shall be as set forth in the
Option Agreement, as adjusted.

     2. DELIVERY OF PAYMENT. Purchaser herewith delivers to the Company the full
purchase price for the Shares (either in cash or by check).

     3. REPRESENTATION OF PURCHASER.  Purchaser  acknowledges that Purchaser has
received,  read, and understood the Option  Agreement and agrees to abide by and
be bound by its terms and conditions.

     4.  RIGHTS  AS  SHAREHOLDER.  Until  the  issuance  (as  evidenced  by  the
appropriate  entry on the books of the Company or of a duly authorized  transfer
agent of the Company) of the stock  certificate  evidencing the Shares, no right
to vote or receive  dividends or any other rights as a  shareholder  shall exist
with respect to the Shares,  notwithstanding the exercise of the Option. A share
certificate for the number of Shares so acquired shall be issued to the Optionee
as soon as practicable after exercise of the Option.

     5. TAX  CONSULTATION.  Purchaser  understands  that  Purchaser  may  suffer
adverse tax  consequences as a result of Purchaser's  purchase or disposition of
the Shares.  Purchaser  represents  that  Purchaser has  consulted  with any tax
consultants  Purchaser  deems  advisable  in  connection  with the  purchase  or
disposition  of the Shares and that  Purchaser is not relying on the Company for
any tax advice.

     6.  ENTIRE  AGREEMENT.  The  Option  Agreement  is  incorporated  herein by
reference.  This Exercise Notice and the Option Agreement  constitute the entire
agreement of the parties and supersede in their entirety all prior  undertakings
and  agreements of the Company and Optionee  with respect to the subject  matter
hereof.

Submitted by:                           Accepted by:

OPTIONEE:


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


Address:


                                        By:
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                                        Its:
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