Reinforced Plastic Composites Production: National Emission Standards for Hazardous Air Pollutants

January 19, 2024



Contact Information

For further information concerning applicability and rule determinations, contact the appropriate State or local agency representative. For information concerning the analyses performed in developing the NESHAP, contact Keith Barnett, U.S. EPA, Emission Standards Division, Minerals and Inorganic Chemicals Group, C504-05, Research Triangle Park, North Carolina 27711, (919) 541-5605,


This action promulgates national emissions standards for hazardous air pollutants (NESHAP) for new and existing reinforced plastic composites production facilities. The NESHAP regulate production and ancillary processes used to manufacture products with thermoset resins and gel coats. Reinforced plastic composites production facilities emit hazardous air pollutants (HAP), such as styrene, methyl methacrylate (MMA), and methylene chloride (dichloromethane). These HAP have adverse health effects including headache, fatigue, depression, irritation of skin, eyes, and mucous membranes. Methylene chloride has been classified as a probable human carcinogen. The NESHAP will implement section 112(d) of the Clean Air Act (CAA) by requiring all major sources in this category to meet HAP emissions standards reflecting the application of the maximum achievable control technology (MACT). We estimate the final NESHAP will reduce nationwide emissions of HAP from these facilities by approximately 7,682 tons per year (tpy) (43 percent).