Company expands its building products business with a leading recycled plastic materials processor Acquisition supports Westlake’s growth trajectory and meeting its ESG commitments Westlake Chemical Corporation (NYSE: WLK) today announced that it has completed the acquisition of Dimex LLC, from Grey Mountain Partners, a private equity firm. “The acquisition of Dimex underscores our longstanding commitment to stewardship of the environment and recycling, and to taking actions that contribute to a sustainable, circular economy,” said Robert Buesinger, Executive Vice President, Vinyl Products of Westlake Chemical Corporation. “We are at an important societal inflection point where consumers prefer and are willing to pay for products made with recyclable materials. Dimex produces a variety of consumer products made from post-industrial-recycled polyvinyl chloride, polyethylene and thermoplastic elastomer materials, which will make this transaction an important piece of Westlake’s growth

Westlake Chemical Corporation (NYSE: WLK) today issued a statement regarding Hurricane Ida, which made landfall near its plants in Louisiana and Mississippi. Westlake’s primary concern is for the safety of our employees and the communities in which we operate. We are working to assist our employees and their families as needed. Following initial facility assessments, Westlake believes it has incurred limited physical damage. Restart of the facilities, which Westlake shut down as a precautionary measure in advance of the storm, will primarily depend upon the availability of electricity, industrial gases, and other utilities and feedstocks. The statements in this release relating to matters that are not historical facts, such as Westlake’s belief that it has incurred limited physical damage and the anticipated restart of its facilities, are forward-looking statements. These forward-looking statements could be adversely affected by a variety of known and unknown risks, uncertainties and

North American Pipe Corporation (NAPCO), a subsidiary of Westlake Chemical Corporation (NYSE: WLK), today announced that it acquired LASCO Fittings LLC, a Brownsville, Tennessee-based, leading designer, engineer and manufacturer of injected-molded PVC fittings, from Aalberts, NV. “We are pleased to complete this important strategic acquisition and to welcome LASCO Fittings and its talented team into the Westlake family of companies,” said Andre Battistin, vice president, NAPCO Pipe & Fittings. “By adding LASCO Fittings to our product mix, NAPCO will expand into additional markets, particularly as LASCO specializes in half-inch to four-inch fittings and serves the plumbing, pool and spa, industrial, irrigation and retail markets in the United States. LASCO’s product mix is very complementary to our existing range of pipe and fittings products primarily with diameters of four or more inches and will bring additional fittings products to NAPCO’s offerings.” LASCO Fittings will