§57.22217. Seals and stoppings (I-A, I-B, and I-C mines).
30 C.F.R. § 57.22217
All seals, and those stoppings that separate main intake from main return airways, shall be of substantial construction and constructed of noncombustible materials, except that stoppings constructed of brattice materials may be used in face areas.
Notes, amendments, and revision history
Authority
Authority: 30 U.S.C. 811.
Source
Source: 52 FR 24941, July 1, 1987, unless otherwise noted.
Authority
Authority: 30 U.S.C. 811.
Source
Source: 50 FR 4082, Jan. 29, 1985, unless otherwise noted.