ACC 1,3-butadiene TSCA Risk Evaluation Consortium is comprised of companies that manufacture or process 1,3-butadiene. In an effort to inform the U.S. EPA risk evaluation of 1,3-butadiene as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act of 2016 the TSCA Risk Evaluation Consortium compiled and analyzed existing industrial hygiene data to support EPA’s exposure assessment of workers and occupational non-users associated with the Manufacturing and Processing (Processing as a Reactant) conditions of use, as described in EPA’s Final Scope of the Risk Evaluation for 1,3-Butadiene (Scoping Document).