CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH (parts 56 to 58) > PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES > SUBPART T—Safety Standards for Methane in Metal and Nonmetal Mines (§57.22001 to §57.22608) > 57.22608—Secondary blasting (I-A, II-A, and V-A mines).

57.22608—Secondary blasting (I-A, II-A, and V-A mines).

Prior to secondary blasting, tests for methane shall be made in the mine atmosphere at blast sites by a competent person. Secondary blasting shall not be done when 0.5 percent or more methane is present.