OxyChem Corporate Headquarters, Texas

Headquartered in Dallas, OxyChem is the chemical subsidiary of the Occidental Petroleum Corporation, based in Los Angeles. OxyChem is a major producer of PVCs, chlorine, and caustic soda, used as base materials in the plastics, chemicals, and water treatment industries. As of 2014, OxyChem is the world's largest producer of caustic potash and calcium chloride. The company operates over 20 plants in the U.S., six of them in Texas; in Dallas, Deer Park, Laporte, Pasadena, and Ingleside.