---identifier: "/us/cfr/t40/s279.21"source: "ecfr"legal_status: "authoritative_unofficial"title: "40 CFR § 279.21 - Hazardous waste mixing."title_number: 40title_name: "Protection of Environment"section_number: "279.21"section_name: "Hazardous waste mixing."chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"subchapter_number: "I"subchapter_name: "SOLID WASTES"part_number: "279"part_name: "STANDARDS FOR THE MANAGEMENT OF USED OIL"positive_law: falsecurrency: "2026-04-05"last_updated: "2026-04-05"format_version: "1.1.0"generator: "[email protected]"authority: "Sections 1006, 2002(a), 3001 through 3007, 3010, 3014, and 7004 of the Solid Waste Disposal Act, as amended (42 U.S.C. 6905, 6912(a), 6921 through 6927, 6930, 6934, and 6974); and sections 101(37) and 114(c) of CERCLA (42 U.S.C. 9601(37) and 9614(c))."regulatory_source: "57 FR 41612, Sept. 10, 1992, unless otherwise noted."cfr_part: "279"---
Identifier
/us/cfr/t40/s279.21
Currency
2026-04-05
Positive Law
No
Updated
2026-04-05
Chapter
Environmental Protection Agency
Authority
Sections 1006, 2002(a), 3001 through 3007, 3010, 3014, and 7004 of the Solid Waste Disposal Act, as amended (42 U.S.C. 6905, 6912(a), 6921 through 6927, 6930, 6934, and 6974); and sections 101(37) and... Sections 1006, 2002(a), 3001 through 3007, 3010, 3014, and 7004 of the Solid Waste Disposal Act, as amended (42 U.S.C. 6905, 6912(a), 6921 through 6927, 6930, 6934, and 6974); and sections 101(37) and 114(c) of CERCLA (42 U.S.C. 9601(37) and 9614(c)).
# 279.21 Hazardous waste mixing.(a) Mixtures of used oil and hazardous waste must be managed in accordance with § 279.10(b).(b) The rebuttable presumption for used oil of § 279.10(b)(1)(ii) applies to used oil managed by generators. Under the rebuttable presumption for used oil of § 279.10(b)(1)(ii), used oil containing greater than 1,000 ppm total halogens is presumed to be a hazardous waste and thus must be managed as hazardous waste and not as used oil unless the presumption is rebutted. However, the rebuttable presumption does not apply to certain metalworking oils/fluids and certain used oils removed from refrigeration units.[57 FR 41612, Sept. 10, 1992, as amended at 58 FR 26425, May 3, 1993]