Exhibit 3.25

STATE OF DELAWARE
SECRETARY OF STATE
DIVISION OF CORPORATIONS
FILED 04:00 PM 06/06/1991
751157066-2262536



                            CERTIFICATE OF AMENDMENT

                                     OF THE

                          CERTIFICATE OF INCORPORATION

                                       OF

                                   ISP 9 CORP.

                        PURSUANT TO SECTIONS 228 AND 242
                         OF THE GENERAL CORPORATION LAW
                            OF THE STATE OF DELAWARE

                  Stephen A. Block, Senior Vice President of ISP 9 Corp. (the
"Corporation"), does hereby certify as follows:

                  1. The Certificate of Incorporation of the Corporation was
filed in the Office of the Secretary of State of the State of Delaware on the
8th day of May 1991.

                  2. The Corporation elects, pursuant to Section 242 of the
General Corporation Law of the State of Delaware, to amend article "FIRST" of
the Certificate of Incorporation to read in its entirety as follows:

                  "FIRST: The name of the Corporation is ISP Environmental
Services Inc."


                  3. Such amendment has been duly adopted in accordance with the
provisions of Section 242 of the General Corporation Law of the State of
Delaware, by the written consent, in accordance with the provisions of

Section 228 of such statute, of the holder of all outstanding stock entitled to
vote thereon.

                  IN WITNESS WHEREOF, the Corporation has duly caused this
Certificate of Amendment to be executed on its behalf by its Senior Vice
President and attested by its Assistant Secretary, this 28th day of May, 1991.

                                   ISP 9 CORP.



                                   By:    /s/ Stephen A. Block
                                        ________________________________________
                                         Stephen A. Block
                                         Senior Vice President

Attest:

  /s/ Deborah D. Lawson
________________________________________
Deborah D. Lawson
Assistant Secretary


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STATE OF DELAWARE
SECRETARY OF STATE
DIVISION OF CORPORATIONS
FILED 04:30 PM 05/08/1991
751128016-2262536



                          CERTIFICATE OF INCORPORATION

                                       OF

                                   ISP 9 CORP.

                  THE UNDERSIGNED, being a natural person for the purpose of
organizing a corporation under the General Corporation Law of the State of
Delaware, hereby certifies that:

                  First: The name of the Corporation is ISP 9 Corp.

                  Second: The address of the registered office of the
Corporation in the State of Delaware is 32 Loockerman Square, Suite L-100, City
of Dover, County of Kent, State of Delaware. The name of the registered agent of
the Corporation in the State of Delaware at such address is The Prentice-Hall
Corporation System, Inc.

                  Third: The purpose of the Corporation is to engage in any
lawful act or activity for which corporations may be organized under the General
Corporation Law of the State of Delaware, as from time to time amended.

                  Fourth: The total number of shares of capital stock which the
Corporation shall have authority to issue is 100, all of which shares shall be
Common Stock having a par value of $.001.

                  Fifth: The name and mailing address of the incorporator is
Donald Whittaker, c/o Weil, Gotshal & Manges, 767 Fifth Avenue, New York, New
York 10153.

                  Sixth: In furtherance and not in limitation of the powers
conferred by law, subject to any limitations contained elsewhere in these
articles of incorporation, by-laws of the Corporation may be adopted, amended or
replealed by a majority of the board of directors of the Corporation, but any
by-laws adopted by the board of directors may be amended or repealed by the
stockholders entitled to vote thereon. Election of directors need not be by
written ballot.

                  Seventh: (a) A director of the Corporation shall not be
personally liable either to the Corporation or to any stockholder for monetary
damages for breach of fiduciary duty as a director, except (i) for any breach of
the director's duty of loyalty to the Corporation or its stockholders, or (ii)
for acts or omissions which are not in good faith or which involve intentional

misconduct or knowing violation of the law, or (iii) for any matter in respect
of which such director shall be liable under Section 174 of Title 8 of the
General Corporation Law of the State of Delaware or any amendment thereto or
successor provision thereto, or (iv) for any transaction from which the director
shall have derived an improper personal benefit. Neither amendment nor repeal of
this paragraph (a) nor the adoption of any provision of the Certificate of
Incorporation inconsistent with this paragraph (a) shall eliminate or reduce the
effect of this paragraph (a) in respect of any matter occurring, or any cause of
action, suit or claim that, but for this paragraph (a) of this Article, would
accrue or arise, prior to such amendment, repeal or adoption of an inconsistent
provision.

                  (b) The Corporation shall indemnify any person who was or is a
party or is threatened to be made a party to, or testifies in, any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative in nature, by reason of the fact that such
person is or was a director, officer, employee or agent of the Corporation, or
is or was serving at the request of the Corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, employee
benefit plan, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by such person in connection with such action, suit or proceeding to
the full extent permitted by law, and the Corporation may adopt By-laws or enter
into agreements with any such person for the purpose of providing for such
indemnification.

                  IN WITNESS WHEREOF, the undersigned has duly executed this
Certificate of Incorporation on this 8th day of May, 1991.

                                     /s/ Donald Whittaker
                                     ___________________________________________
                                     Donald Whittaker
                                     Sole Incorporator



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