<PAGE>

                           LYONDELL CHEMICAL COMPANY

                               POWER OF ATTORNEY
                               -----------------

  Each person whose signature appears below hereby constitutes and appoints Dan
F. Smith, Robert T. Blakely, Charles L. Hall, and Kerry A. Galvin and each of
them, his or her true and lawful attorneys-in-fact and agents, with full power
of substitution and resubstitution, for him or her and in his or her name, place
and stead, in any and all capacities, in connection with any outstanding
securities of Lyondell Chemical Company (the "Company"), or any public offering
or other issuance of any securities of the Company authorized by the Board of
Directors of the Company, or by the Executive Committee thereof pursuant to due
authorization by such Board, (1) to execute and file, or cause to be filed, with
the United States Securities and Exchange Commission (the "Commission"), (A)
registration statements and any and all amendments (including post-effective
amendments), and exhibits thereto and any and all other documents in connection
therewith as required by the Commission in connection with such registration
under the Securities Act of 1933, as amended, and (B) any report or other
document required to be filed by the Company with the Commission pursuant to the
Securities Exchange Act of 1934, as amended, (2) to execute and file, or cause
to be filed, any application for registration or exemption therefrom, any report
or any other document required to be filed by the Company under the Blue Sky or
securities law of any state and to furnish any other information required in
connection therewith, (3) to execute and file, or cause to be filed, any
application for registration or exemption therefrom under the securities laws of
any jurisdiction outside the United States of America, including any reports or
other documents required to be filed subsequent to the issuance of such
securities, and (4) to execute and file, or cause to be filed, any application
for listing such securities on the New York Stock Exchange, or any other
securities exchange in any other jurisdiction where any such securities are
proposed to be sold, granting to such attorneys-in-fact and agents, and each of
them,
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full power and authority to do and perform each and every act required to
be done as he or she might or could do in person, hereby ratifying and
confirming all that such attorneys-in-fact and agents, and each of them, may
lawfully do or cause to be done by virtue of this power of attorney.  Each
person whose signature appears below may at any time revoke this power of
attorney as to himself or herself only by an instrument in writing specifying
that this power of attorney is revoked as to him or her as of the date of
execution of such instrument or at a subsequent specified date.  This power of
attorney shall be revoked automatically with respect to any person whose
signature appears below effective on the date he or she ceases to be a member of
the Board of Directors or an officer of the Company.  Any revocation hereof
shall not void or otherwise affect any acts performed by any attorney-in-fact
and agent named herein pursuant to this power of attorney prior to the effective
date of such revocation.

Dated:  February 8, 2002

<TABLE>
<CAPTION>
                  SIGNATURE                                           TITLE
                  ---------                                           -----
<S>                                              <C>

/s/ DAN F. SMITH                                 President, Chief Executive Officer and Director
----------------------------------------------
Dan F. Smith

/s/ ROBERT T. BLAKELY                                     Executive Vice President and
----------------------------------------------               Chief Financial Officer
Robert T. Blakely

/s/ CHARLES L. HALL                                       Vice President and Controller
----------------------------------------------
Charles L. Hall

/s/ KERRY A. GALVIN                               Vice President, General Counsel and Secretary
----------------------------------------------
Kerry A. Galvin


</TABLE>
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<TABLE>
<CAPTION>
                  SIGNATURE                                           TITLE
                  ---------                                           -----

<S>                                              <C>
/s/ DR. WILLIAM T. BUTLER                                     Chairman and Director
----------------------------------------------
Dr. William T. Butler


/s/ CAROL A. ANDERSON                                               Director
----------------------------------------------
Carol A. Anderson


/s/ TRAVIS ENGEN                                                    Director
----------------------------------------------
Travis Engen


/s/ DAVID J. LESAR                                                  Director
----------------------------------------------
David J. Lesar


/s/ STEPHEN F. HINCHLIFFE, JR.                                      Director
----------------------------------------------
Stephen F. Hinchliffe, Jr.


/s/ DUDLEY C. MECUM II                                              Director
----------------------------------------------
Dudley C. Mecum II


/s/ DR. WILLIAM R. SPIVEY                                           Director
----------------------------------------------
Dr. William R. Spivey


/s/ PAUL R. STALEY                                                  Director
----------------------------------------------
Paul R. Staley

</TABLE>