{"data":{"id":"us/40-cfr-appendix-table-1-to-subpart-hhh-of-part-63","jurisdiction":"us","citation":"40 CFR Appendix: Table 1 to Subpart HHH of Part 63","heading":"Appendix: Table 1 to Subpart HHH of Part 63—List of Hazardous Air Pollutants (HAP) for Subpart HHH","body":"CAS Number a Chemical name\n75070 Acetaldehyde\n71432 Benzene (includes benzene in gasoline)\n75150 Carbon disulfide\n463581 Carbonyl sulfide\n100414 Ethyl benzene\n107211 Ethylene glycol\n75050 Acetaldehyde\n50000 Formaldehyde\n110543 n-Hexane\n91203 Naphthalene\n108883 Toluene\n540841 2,2,4-Trimethylpentane\n1330207 Xylenes (isomers and mixture)\n95476 o-Xylene\n108383 m-Xylene\n106423 p-Xylene\na CAS numbers refer to the Chemical Abstracts Services registry number assigned to specific compounds, isomers, or mixtures of compounds.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER C—AIR PROGRAMS","PART 63—NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES","Subpart HHH—National Emission Standards for Hazardous Air Pollutants From Natural Gas Transmission and Storage Facilities"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"bbd4bbd458c5a299db852078474803557ecd8e17ecf0f3f652864726dfaa9dab","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-63.1288-63.1289","next":"us/40-cfr-appendix-table-2-to-subpart-hhh-of-part-63"},"notice":"GroundRules: Original legal text. Not legal advice."}