POWER OF ATTORNEY PRIVATE  
The undersigned, an "officer" of Lyondell Chemical Company ("Lyondell") within the meaning of 
Section 16 of the Securities Exchange Act of 1934 (an "Executive Officer"), does hereby make, constitute 
and appoint for a term commencing November 30, 2005 and expiring the date I cease to hold office as an 
Executive Officer, Kerry A. Galvin, Senior Vice President, General Counsel and Secretary and Gerald A. 
O'Brien, Vice President, Deputy General Counsel, and each of them, my true and lawful attorney for me 
in my name and on my behalf to approve, execute, acknowledge and deliver from time to time, as 
appropriate a Report on Form 3, Form 4 or on Form 5 that is required to be filed by me with the Securities 
and Exchange Commission pursuant to Section 16(a) of the Securities Exchange Act of 1934. The said 
Kerry A. Galvin and Gerald A. O'Brien are each severally empowered, as Attorney in Fact, to approve, 
execute and deliver any such Reports as fully as if I had personally signed any such Report.
The undersigned hereby grants to each such attorney-in-fact full power and authority to do and perform 
any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise of any of 
the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could 
do if personally present, with full power of substitution or revocation, hereby ratifying and confirming all 
that such attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall lawfully do or cause to 
be done by virtue of this power of attorney and the rights and powers herein granted.  The undersigned 
acknowledges that the foregoing attorney-in-fact, in serving in such capacity at the request of the 
undersigned, are not assuming, nor is the Company assuming, any of the undersigned's responsibilities to 
comply with Section 16 of the Securities Exchange Act of 1934.
Executed this 30th day of November, 2005.
By:         /s/ Edward J. Dineen                                                                
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