30 C.F.R. § 57.8532 Opening and closing ventilation doors.
Title 30 - Mineral Resources
When ventilation control doors are opened as a part of the normal mining cycle, they shall be closed as soon as possible to re-establish normal ventilation to working places.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart G—Ventilation
Underground Only
§ 57.8532 Opening and closing ventilation doors.
