<PAGE>
 
                                                                    EXHIBIT 24.2

                                  CERTIFICATE
                         HOECHST CELANESE CORPORATION
                         ----------------------------


TO WHOM IT MAY CONCERN:

          I, Edmond A. Collins, certify that I am the duly certi fied and
qualified Corporate Secretary of Hoechst Celanese Corpora tion (the
"Corporation"), a Delaware corporation, and that the following is a true,
correct and complete copy of a resolution passed by the Board of Directors of
the Corporation by Unanimous Consent Resolution on February 12, 1996, and said
resolution has not been amended or rescinded and is in full force and effect:

               RESOLVED, that each officer and director who is authorized under
     law to sign (on behalf of the Corpora tion or as an officer or director
     thereof) the Corpora tion's documents that are filed with the Securities
     and Exchange Commission during 1996 is hereby authorized to execute a power
     of attorney appointing Harry R. Benz, Thomas F. Kennedy or David A. Jenkins
     as his true and lawful attorney to execute in his name, place and stead in
     any such capacity and on behalf of the Corporation such documents and all
     amendments and other papers in connection therewith, and to file the same
     with the Securities and Exchange Commission, each of said attor neys to
     have full power to act without the others, and to do and perform, in the
     name and on behalf of the officers and directors who shall have executed
     such power-of-attorney, every act necessary to be done as such officer or
     director could do in person; such documents shall include but not be
     limited to the Annual Report on Form 10-K for fiscal year 1995 that is
     filed pursuant to the Securities Exchange Act of 1934.

          IN WITNESS WHEREOF, I have hereunto set my hand and the
seal of this Corporation this 5th day of March, 1996.



                                              /s/ E. A. Collins
                                              ----------------------------
                                                  E. A. Collins
                                                  Secretary



[SEAL]
<PAGE>
 
                          HOECHST CELANESE CORPORATION
                          ----------------------------

                          UNANIMOUS CONSENT RESOLUTION
                          ----------------------------

                           OF THE BOARD OF DIRECTORS
                           -------------------------


In lieu of a Special Meeting of the Board of Directors of Hoechst Celanese
Corporation, the undersigned, being all the Directors of the Corporation, do
hereby unanimously consent to the following resolution:

     Authorize Powers-of-Attorney to sign documents filed with the Securities
     ------------------------------------------------------------------------
     and Exchange Commission
     -----------------------

WHEREAS, the Corporation files documents with the Securities and Exchange
Commission that are required to be signed by certain officers and directors, and
such documents receive an adequate review before filing;

NOW, THEREFORE, the Board adopts the following resolution which authorizes the
signing of such documents by powers-of-attorney:


     RESOLVED, that each officer and director who is authorized under law to
sign (on behalf of the Corporation or as an officer or director thereof) the
Corporation's documents that are filed with the Securities and Exchange
commission during 1996 is hereby authorized to execute a power of attorney
appointing Harry R. Benz, Thomas F. Kennedy or David A. Jenkins as his true and
lawful attorney to execute in his name, place and stead in any such capacity and
on behalf of the Corporation such documents and all amendments and other papers
in connection therewith, and to file the same with the Securities and Exchange
Commission, each of said attorneys to have full power to act without the others,
and to do and perform, in the name and on behalf of the officers and directors
who shall have executed such power-of-attorney, every act necessary to be done
as such officer or director could do in person; such documents shall include but
not be limited to the Annual Report on Form 10-K for fiscal year 1995 that is
filed pursuant to the Securities Exchange Act of 1934.
<PAGE>
 
The foregoing action is taken pursuant to section 141 (f) of the Delaware
General Corporation Law and shall be of the same force and effect as if
taken at a meeting of the Board of Directors called and held for the
purpose of taking the action set forth above.

IN WITNESS WHEREOF, all of the Directors of the Corporation have affixed
their signature hereto as of the date below written.

 /s/ Harry R. Benz                        /s/ Wiliam B. Harris
------------------------                  -------------------------
    Harry R. Benz                             William B. Harris



/s/ David A. Jenkins                      /s/ Thomas F. Kennedy
------------------------                  ------------------------
    David A. Jenkins                          Thomas F. Kennedy



/s/ Dr. Guenter Metz                       /s/ Dr. Klaus Warning
-------------------------                  ------------------------
    Dr. Guenter Metz                           Dr. Klaus Warning


DATED: February 12, 1996