85. Where, before recommencing work in an underground mine that has been abandoned or part of an underground mine located outside a ventilation circuit, the air quality must be inspected for compliance with in sections 40 and 41 of the Regulation respecting occupational health and safety (chapter S-2.1, r. 13) and its Schedule I, the workers making the check shall:(1) work in groups of at least 2 and remain constantly in sight of each other;
(2) wear a self-contained breathing apparatus as prescribed in subparagraph 1 of the first paragraph and in the second paragraph of section 13;
(3) have measurement instruments for detecting the concentration of oxygen and any contaminant likely to be found in the mine or part of the mine.