30 C.F.R. § 75.1711-2 Sealing of slope or drift openings.
Title 30 - Mineral Resources
Slope or drift openings required to be sealed under §75.1711 shall be sealed with solid, substantial, incombustible material, such as concrete blocks, bricks or tile, or shall be completely filled with incombustible material for a distance of at least 25 feet into such openings.
Title 30: Mineral Resources
PART 75—MANDATORY SAFETY STANDARDS—UNDERGROUND COAL MINES
Subpart R—Miscellaneous
§ 75.1711-2 Sealing of slope or drift openings.
