{"data":{"id":"us/30-cfr-57.22220","jurisdiction":"us","citation":"30 CFR 57.22220","heading":"Air passing unsealed areas (I-A, II-A, III, and V-A mines).","body":"Air that has passed by or through unsealed abandoned or unsealed inactive areas and contains 0.25 percent or more methane shall—\n(a) Be coursed directly to a return airway;\n(b) Be tested daily for methane by a competent person; and\n(c) Not be used to ventilate work places.","path":["Title 30—Mineral Resources","CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR","SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH","PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES","Subpart T—Safety Standards for Methane in Metal and Nonmetal Mines"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-30.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:24Z","sha256":"8b195ff1cf316600e09cd5702464f94bdd3beb948453e359b9a411034809b961","source_id":"us-cfr","stale":true,"prev":"us/30-cfr-57.22219","next":"us/30-cfr-57.22221"},"notice":"GroundRules: Original legal text. Not legal advice."}