US lawFederal (United States)RegulationsTitle 40 CFR — Protection of EnvironmentChapter I — ENVIRONMENTAL PROTECTION AGENCYPart 63 — NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIESSubpart XX — National Emission Standards for Ethylene Manufacturing Process Units: Heat Exchange Systems and Waste Operations63.109140 C.F.R. § 63.1091What do the waste requirements do?Last amended: 2016Year: 2026Length: 35 wordsOfficial source Cite as 40 C.F.R. § 63.1091 (2026)This subpart requires you to comply with 40 CFR part 61, subpart FF, National Emission Standards for Benzene Waste Operations. There are some differences between the ethylene production waste requirements and those of subpart FF.Previous40 C.F.R. § 63.1090Next40 C.F.R. § 63.1092