Westlake is a highly integrated chemical company based in Houston, Texas, and produces both olefin chemicals as well as vinyl products. The firm's olefin segment contributed more than two thirds of Westlake's 2008 sales, and consists of ethylene, polyethylene, and styrene chemicals. Westlake's vinyls segment produces caustic soda as well as PVC and fabricated PVC products, such as pipes and window profiles. Westlake became a publicly traded company in August 2004.