Our commitment to quality products is so strong that it is symbolized through the two check marks that make up the "W" in our logo. We seek to maintain this commitment through an intensive practice of "never-ending process of improvement".

Several of Westlake's operations which produce petrochemicals, plastics, and chlor/alkali & derivatives products have earned the prestigious ISO 9001certification. ISO certification signifies that a company has an ongoing program of continual quality improvement and satisfies customer requirements. ISO 9001:2015 certification indicates that Westlake's production facilities meet rigid quality standards, demand supplier performance, and are committed to continual improvement in order to meet the needs of customers.

Westlake's operations with ISO 9001 certification include the following:

(Click on location below to view certificate)


Axiall Canada Inc., a Westlake company, Beauharnois, Canada (English)

Axiall Canada, Inc., a Westlake company, Beauharnois, Canada (French)

Westlake Aberdeen MS

Westlake Lake Charles South Plant LA

Westlake Natrium WV

Westlake Op-Co Lake Charles LA

Westlake Plaquemine LA

Westlake Gallman, Madison & Prairie MS

Westlake Geismar LA

Westlake Longview TX

Westlake Polymers Sulphur LA

Westlake Styrene Sulphur LA

Westlake Vinyls, Inc. and/or Westlake OpCo: LP, Calvert City KY