30 C.F.R. § 57.6603 Air gap.
Title 30 - Mineral Resources
At least a 15-foot air gap shall be provided between the blasting circuit and the electric power source.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart E—Explosives
Extraneous Electricity—Surface and Underground
§ 57.6603 Air gap.
