Exhibit 3.19

                                                               STATE OF DELAWARE
                                                              SECRETARY OF STATE
                                                        DIVISION OF CORPORATIONS
                                                       FILED 04:00 PM 06/06/1991
                                                             751157067 - 2262528



                            CERTIFICATE OF AMENDMENT

                                     OF THE

                          CERTIFICATE OF INCORPORATION

                                       OF

                       ISP INTERNATIONAL MANAGEMENT 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 International
Management 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
International Corp."

                  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 INTERNATIONAL MANAGEMENT
                                  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
751128008 - 2262528


                          CERTIFICATE OF INCORPORATION

                                       OF

                       ISP INTERNATIONAL MANAGEMENT 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 International
Management 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
repealed 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 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 S 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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