30 C.F.R. § 77.201-2 Methane accumulations; change in ventilation.
Title 30 - Mineral Resources
If, at any time, the air in any structure, enclosure or other facility contains 1.0 volume per centum or more of methane changes or adjustments in the ventilation of such installation shall be made at once so that the air shall contain less than 1.0 volume per centum of methane.
Title 30: Mineral Resources
PART 77—MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES
Subpart C—Surface Installations
§ 77.201-2 Methane accumulations; change in ventilation.
