S-2.1, r. 14 - Regulation respecting occupational health and safety in mines

Full text
89. Main fans and auxiliary fans shall not recirculate air to ventilate an underground work station.
However, reuse of air in a main ventilation circuit or an auxiliary circuit is permitted under the following conditions:
(1)  the concentration of carbon monoxide in the ambient air must be measured at the inlet of each circuit where air is reused;
(2)  these measurements must be taken at least once a week during mucking operations carried out with diesel equipment and each time the ventilation equipment is altered; and
(3)  when the concentration of carbon monoxide exceeds 11.4 mg/m3 (10 ppm), a response plan must be implemented to reduce and maintain the concentration below that level.
The results of those measurements must be recorded in a register.
O.C. 213-93, s. 89; O.C. 42-2004, s. 3.