CFR›Title 10›Chapter II›Part 431›Subpart S ContainsSections 431.321–431.322; Subject groups Energy Conservation Standards–Test ProceduresCorpusDaily eCFRDisplayed edition2026-05-07Last updated2026-05-07 Subpart S—Metal Halide Lamp Ballasts and Fixtures Contents 431.321 § 431.321 Purpose and scope. 431.322 § 431.322 Definitions concerning metal halide lamp ballasts and fixtures. Energy Conservation Standards Energy Conservation Standards Section 431.326 Test Procedures Test Procedures Sections 431.323–431.324 Source74 FR 12075, Mar. 23, 2009, unless otherwise noted. Previous R Subpart R—Walk-in Coolers and Walk-in Freezers Next T Subpart T—Compressors