Westlake operations producing petrochemicals and plastics have earned the prestigious ISO 9001:2000 certification. ISO certification signifies that a company has an ongoing program of continual quality improvement. The ISO 9001:2000 certification indicates that Westlake's production facilities meet rigid standards and supplier requirements.

Westlake Chemical Corporation operations with ISO 9001:2000 certification include the following:

(Click on location below to view certificate)

•  Westlake CA&O
•  Westlake Longview
•  Westlake Monomers
•  Westlake Petrochemicals
•  Westlake Polymers
•  Westlake PVC
•  Westlake Styrene