30 C.F.R. § 75.1711-2

Sealing of slope or drift openings

Read at: eCFRecfr.gov CornellLII GovInfogovinfo.gov CasesGoogle Scholar

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.