EXHIBIT 3.1ss


                                                STATE OF DELAWARE
                                                SECRETARY OF STATE
                                             DIVISION OF CORPORATIONS
                                            FILED 09:00 AM 05/17/2000
                                               001253252 - 3230771


                          CERTIFICATE OF INCORPORATION

                                       OF

                      CROMPTON MANUFACTURING COMPANY, INC.

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

   FIRST. The name of this corporation shall be:

                      CROMPTON MANUFACTURING COMPANY, INC.

   SECOND. Its registered office in the State of Delaware is to be located at
1013 Centre Road, in the City of Wilmington, County of New Castle and its
registered agent at such address is CORPORATION SERVICE COMPANY.

   THIRD. The purpose or purposes of the corporation shall be:

   To engage in any lawful act or activity for which corporations may be
organized under the General Corporation Law of Delaware.

   FOURTH. The total number of shares of stock which this corporation is
authorized to issue is:

One Hundred Shares (100) of Common Stock Without Par Value

   FIFTH. The name and address of the incorporator is as follows:

                  Ronald T. Harris
                  Corporation Service Company
                  1013 Centre Road
                  Wilmington, DE 19805

   SIXTH. The Board of Directors shall have the power to adopt, amend or
repeal the by-laws.

   SEVENTH. No director shall be personally liable to the Corporation or its
stockholders for monetary damages for any breach of fiduciary duty by such
director as a director. Notwithstanding the foregoing sentence, a director
shall be liable to the extent provided by applicable law, (i) for breach of
the director's duty of loyalty to the Corporation or its stockholders, (ii)
for acts or omissions not in good faith or which involve intentional
misconduct





or a knowing violation of law, (iii) pursuant to Section 174 of the Delaware
General Corporation Law or (iv) for any transaction from which the director
derived an improper personal benefit. No amendment to or repeal of this
Article Seventh shall apply to or have any effect on the liability or alleged
liability of any director of the Corporation for or with respect to any acts
or omissions of such director occurring prior to such amendment.

   IN WITNESS WHEREOF, the undersigned, being the incorporator hereinbefore
named, has executed, signed and acknowledged this certificate of incorporation
this fifteenth day of May, A.D., 2000.


                                          /s/ Ronald T. Harris
                                          --------------------------------------
                                          Ronald T. Harris
                                          Incorporator