CERTIFICATE OF AMENDMENT

                                     OF THE

                          CERTIFICATE OF INCORPORATION

                                       OF

                            HUDSON TECHNOLOGIES, INC.

                Under Section 805 of the Business Corporation Law

     WE, the undersigned,  being the President and Secretary,  respectively,  of
HUDSON TECHNOLOGIES, INC., hereby certify:

     The name of the  corporation  is HUDSON  TECHNOLOGIES,  INC.  It was formed
under the name REFRIGERANT RECLAMATION INDUSTRIES, INC.

     The  Certificate of  Incorporation  was filed by the Department of State on
January 11, 1991.

     The Certificate of Incorporation is amended as authorized by Section 801 of
the Business  Corporation  Law to increase the aggregate  number of shares which
the corporation  shall have authority to issue from 20,000,000,  $.01 par value,
to  25,000,000,  $.01 par value;  to designate all of the  additional  shares as
Preferred  Stock; and to state the relative  voting,  dividend,  liquidation and
other rights, preferences and limitations relating to the shares of each class.

     To  effectuate  the  foregoing,   Paragraph  (5)  of  the   Certificate  of
Incorporation,  which refers to the  authorized  shares of the  corporation,  is
hereby amended to read as follows:

     "(5).  The total number of shares of capital  stock which the Company shall
have authority to issue is Twenty-Five  Million  (25,000,000)  shares,  of which
Twenty  Million  (20,000,000)  shares shall be Common Stock,  par value $.01 per
share, and Five Million  (5,000,000)  shares shall be Preferred Stock, par value
$.01 per share.

     The Preferred  Stock may be issued from time to time in one or more series.
The Board of Directors of the Company is hereby expressly authorized to provide,
by  resolution  or  resolutions  duly adopted by it prior to  issuance,  for the
creation  of each  such  series  and to fix  the  designation  and  the  powers,
preferences,  rights,  qualifications,  limitations and restrictions relating to
the shares of each such series.  The  authority  of the Board of Directors  with
respect to each series of Preferred Stock shall include,  but not be limited to,
determining the following:

     (a) the designation of the series and the number of shares to constitute
such series (which number may be increased or decreased from time to time unless
otherwise provided by the Board of Directors);


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     (b) the dividend rate (or method of determining such rate), any conditions
on which and times at which dividends are payable, the preference or relation
which such dividends shall bear to the dividends payable on any other class or
classes or of any other series of capital stock including the Preferred Stock,
and whether such dividends shall be cumulative or non-cumulative;

     (c) whether the series will be redeemable (at the option of the Company or
the holders of such shares or both, or upon the happening of a specified event)
and, if so, the redemption prices and the conditions and times upon which
redemption may take place and whether for cash, property or rights, including
securities of the company or another corporation;

     (d) whether the shares of such series shall be subject to the operation of
a retirement or sinking fund and, if so, the extent to and manner in which any
such retirement or sinking fund shall be applied to the purchase or redemption
of the shares of such series for retirement or other corporate purposes and the
terms and provisions relating to the operation thereof;

     (e) the conversion or exchange rights (at the option of the Company or the
holders of such shares or both, or upon the happening of a specified event), if
any, including the conversion or exchange times, prices, rates, adjustments and
other terms of conversion or exchange;

     (f) whether the shares of such series shall have voting rights in addition
to any voting rights provided as a matter of law and, if so, the terms of such
voting rights, which may be general or limited;

     (g) the conditions or restrictions, if any, upon the creation of
indebtedness of the Company or upon the issue or reissue or sale of any
additional stock, including additional shares of such series or of any other
series of Preferred Stock or of any other class;

     (h) the rights of the holders upon voluntary or involuntary liquidation,
dissolution or winding up of the affairs of the Company or upon any dissolution
of the assets of the Company (including preferences over the Common Stock or
other class or classes or series of capital stock including the Preferred
Stock);

     (i) the preemptive rights, if any, to subscribe to additional issues of
stock or securities of the Company;

     (j) the limitations and restrictions, if any, to be effective while any
shares of such series are outstanding upon the payment of dividends or the
making of other distributions on, and upon the purchase, redemption or other
acquisition by the Company of, the Common Stock or shares of stock of any other
class or any other series of Preferred Stock; and

     (k) such other special rights and privileges, if any, for the benefit of
the holders of the Preferred Stock, as shall not be inconsistent with the
provisions of the Certificate of Incorporation, as amended, or applicable law.

         All shares of Preferred Stock of the same series shall be identical in
all


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respects, except that shares of any one series issued at different times may
differ as to dates, if any, from which dividends thereon may accumulate. All
shares of Preferred Stock redeemed, purchased or otherwise acquired by the
Company (including shares surrendered for conversion) shall be cancelled and
thereupon restored to the status of authorized but unissued shares of Preferred
Stock undesignated as to series.

         Except as otherwise may be required by law, and except as otherwise may
be provided in the Certificate of Incorporation, as amended, or in the
resolution of the Board of Directors of the Company creating any series of
Preferred Stock, the Common Stock shall have the exclusive right to vote for the
election of directors and for all other purposes, each holder of the Common
Stock being entitled to one vote for each share thereof held.

         Except as may be stated and expressed in any resolution or resolutions
of the Board of Directors providing for the issue of any series of Preferred
Stock, (i) any amendment to the Certificate of Incorporation which shall
increase or decrease the number of shares of any class or classes of authorized
capital stock of the Company (but not below the number of shares thereof then
outstanding) may be adopted by the affirmative vote of the holders of a majority
of the outstanding shares of the voting stock of the Company, and (ii) no holder
of capital stock shall be entitled as a matter of right to subscribe for or
purchase, or have any preemptive right with respect to, any apart of any new or
additional issue of stock of any class whatsoever, or of securities convertible
into any stock of any class whatsoever, whether now or hereafter authorized and
whether issued for cash or other consideration or by way of dividend."

         The amendment of the Certificate of Incorporation was authorized by
unanimous written consent, setting forth the action taken, signed by all of the
members of the Board of Directors, followed by the vote of the holders of a
majority of the outstanding shares entitled to vote thereon at a meeting of the
shareholders.

         IN WITNESS WHEREOF, we have hereunto executed this Certificate of
Amendment and do affirm the foregoing as true under the penalties of perjury
this 16th day of March, 1999.


                                           /s/ Kevin J. Zugibe
                                           -----------------------------
                                           Kevin J. Zugibe,
                                           Chairman of the Board


                                           /s/ Stephen P. Mandracchia
                                           -----------------------------
                                           Stephen P. Mandracchia,
                                           Secretary


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