This life cycle assessment of olefins was commissioned and funded by the American Chemistry Council (ACC) Plastics Division to update the original data in the 2011 report, Cradle-to-Gate Life Cycle Inventory of Nine Plastic Resins and Four Polyurethane Precursors, as well as the U.S. life cycle inventory (LCI) plastics database. The report was made possible through the cooperation of ACC member companies, who provided data for the production of olefins.