Propylene is an olefin molecule of chemical formula C3H6 produced from natural gas liquids and refinery streams in steam crackers. Chevron Phillips Chemical uses propylene internally to manufacture polyethylene, polypropylene, alpha olefins, and styrene and sells it to external customers who produce these and other materials such as polyester, acrylics, ethylene glycol antifreeze, polyvinyl chloride (PVC), propylene oxide, oxo alcohols, and isopropanol.