Removal of gases from underground mines

(1) The manager shall ensure that the air in all parts of the mine where persons are working or travelling, or may work or travel, is free from injurious or dangerous concentrations of noxious gases and contains sufficient oxygen to obviate danger to the health of anyone in the mine. mines. (2) Any concentration of a contaminant in excess of the permissible concentration of threshold limit values and biological exposure indices published by the American Conference of Governmental Industrial Hygienists (ACGIH) and as amended from time to time, shall not be exceeded. Permissible concentrations of (3) The return air from all working places shall, as far as practicable, be routed directly to the exhaust airway. Exhaust airways. (4) Where the main system of ventilation for an underground mine is stopped, other than through a brief interruption of the Interruption of 100 power supply, all persons shall be withdrawn to the surface or an approved refuge station and no one shall enter the mine until the ventilation has been restored. Auxiliary (5) The manager shall ensure that every mine working that is advanced more than 20 meters (66 feet) from the main ventilation circuit, and every raise and sub-drift more than 10 meters (33 feet) from the main ventilation circuit shall be provided with auxiliary ventilation. Prevention of recirculation of air. (6) The manager shall ensure that every auxiliary fan is supplied with sufficient fresh air and installed in such a manner as to prevent recirculation of the air. Major ventilation (7) The manager shall ensure that measurements of the quantity of air flowing at the main fan, in all main airways, and at all major ventilation splits, are taken at intervals not exceeding 3 months. (8) In an underground mine or part of a mine where diesel equipment is operating, measurements of the quantity of gas air flowing shall be taken at intervals not exceeding one week and tests shall be made at least once a shift, in the general body of air, on the exhaust side of the operating diesel equipment, for nitrogen dioxide, carbon monoxide and any other gases specified by the Inspector. Ventilation and gas measurements. Recording measurements. (9) The results of measurements and tests shall be recorded in a book kept for that purpose and made available to the doors. (10) All doors for regulating or controlling ventilation shall close automatically or be provided with a device for opening and closing them. Barricading inactive (11) The manager shall ensure that any part of the underground mine that is not being ventilated shall be effectively barricaded and posted with signs warning that entry 101 is prohibited and before anyone is permitted to enter that part of the mine that a qualified person examine it for oxygen deficiency, the presence of toxic or noxious gases or any other dangerous condition. (12) A worker shall not return, or be permitted to return to a workplace after a blasting operation until the worker is sure that the gases produced by the explosives have been removed or diluted by the ventilation system. Ventilation after