(a) When auxiliary fans and tubing are used for face ventilation, each auxiliary fan shall be-
(b) If a deficiency exists in any auxiliary fan system, the deficiency shall be corrected or the auxiliary fan shall be deenergized immediately.
(c) If the air passing through an auxiliary fan or tubing contains 1.0 percent or more methane, power to electrical equipment in the working place and to the auxiliary fan shall be deenergized, and other mechanized equipment in the working place shall be shut off until the methane concentration is reduced to less than 1.0 percent.
(d) When an auxiliary fan is stopped-
053-4 Wyo. Code R. § 75.331