CFR›Title 42›Chapter I›Part 21›Subpart A ContainsSection 21.1CorpusDaily eCFRDisplayed edition2026-04-15Last updated2026-04-15 Subpart A—Definitions Sections 21.1 § 21.1 Meaning of terms. AuthoritySec. 215, 58 Stat. 690, as amended; 42 U.S.C. 216. Next B Subpart B—Appointment