PROMISSORY NOTE

                                                        Dated: December 20, 1999
$50,000
                                                             State of New Jersey
Principal Amount

FOR VALUE RECEIVED, the undersigned hereby promises to pay to the order of
Thomas MeKean, Esq., 59 Temple Place-Ste. 408, Boston, MA 02111, the sum of
Fifty Thousand Dollars ($50,000), together with interest thereon at the rate of
10% per annum on the unpaid balance. Said sum shall be paid in the manner
following:

                          DUE IN FULL FEBRUARY 20, 2000

All payments shall be first applied to interest and the balance to principal.
This note may be prepaid at any time, in whole or in part, without penalty. All
prepayments shall be applied in reverse order of maturity.

Payments not made within ten (10) days of due date shall be subject to a late
charge of 1% of said payment. All payments hereunder shall be made to such
address as may from time to time be designated by any holder hereof.

The undersigned corporation agrees to remain fully bound hereunder until this
note shall be fully paid and waive demand, presentment and protest and all
notices thereto and further agree to remain bound, notwithstanding any
extension, renewal, modification, waiver, or other indulgence by any holder or
upon the discharge or release of any obligor hereunder or to this note. No
modification or indulgence by any holder hereof shall be binding unless in
writing; and any indulgence on any one occasion shall not be an indulgence for
any other or future occasion. Any modification or change of terms, hereunder
granted by any holder hereof, shall be valid and binding upon the undersigned
corporation, notwithstanding the acknowledgment of any of the undersigned. This
note shall take effect as a sealed instrument and shall be construed, governed
and enforced in accordance with the laws of the State first appearing at the
head of this note. The undersigned hereby execute this note as principals and
not as sureties.




Signed in the presence of:

/s/ [ILLEGIBLE]                           TECH LABORATORIES. INC.
- ----------------------------              Borrower
Witness
                                          /s/ Bernard M. Ciongoli
- ----------------------------              ----------------------------
Witness                                   Bernard M. Ciongoli, President
                                          For Tech Laboratories, Inc.