[Code of Federal Regulations] [Title 24, Volume 1] [Revised as of April 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 24CFR21.610] [Page 245] TITLE 24--HOUSING AND URBAN DEVELOPMENT PART 21_GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) --Table of Contents Subpart F_Definitions Sec. 21.610 Controlled substance. Controlled substance means a controlled substance in schedules I through V of the Controlled Substances Act (21 U.S.C. 812), and as further defined by regulation at 21 CFR 1308.11 through 1308.15.