If 1.5% or higher concentration of flammable gas is detected in air returning from an underground area or areas, the persons shall be withdrawn and the power cut off to the portion of the mine endangered by such flammable gas until the concentration of such gas is reduced to 1.0% or less.
4 Va. Admin. Code § 25-40-5320
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.