Instruments shall be provided to test the mine atmosphere quantitatively for carbon monoxide, nitrogen dioxide, and other gases that occur in the mine. Tests shall be conducted as frequently as necessary by the operator to ensure that the required quality of air is maintained.
4 Va. Admin. Code § 25-40-3220
Statutory Authority
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.