40 CFR 82.82: Definitions.

(a) Class I substance means any substance designated as class I by EPA pursuant to 42 U.S.C. 7671(a), including but not limited to chlorofluorocarbons, halons, carbon tetrachloride and methyl chloroform.

(b) Class II substance means any substance designated as class II by EPA pursuant to 42 U.S.C. 7671(a), including but not limited to hydrochlorofluorocarbons.

(c) Controlled substance means a class I or class II ozone-depleting substance.

(d) Department, agency and instrumentality of the United States refers to any executive department, military department, or independent establishment within the meaning of 5 U.S.C. 101, 102, and 104(1), respectively, any wholly owned Government corporation, the United States Postal Service and Postal Rate Commission, and all parts of and establishments within the legislative and judicial branches of the United States.