September 10, 2008 - Responses to the collection are mandatory under 40 CFR part 63, subpart U--National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins. Respondents/Affected Entities: Manufacturers of acrylonitrile butadiene styrene resin, styrene acrylonitrile resin, methyl methacrylate acrylonitrile butadiene styrene resin, methyl methacrylate butadiene styrene resin, polystyrene resin, and nitrile resin.