Ignition risks
23.—(1) The mine operator must ensure that when in any zone, or at any place within a zone, classified in accordance with regulation 7(1) of DSEAR—
(a)the concentration of a flammable gas exceeds 25% by volume of the lower explosive limit of that gas in the general body of air, all activities that present a significant ignition risk are halted until the concentration is reduced so that it is below that level; and
(b)in the event that the concentration exceeds 40% by volume of the lower explosive limit of that gas in the general body of air, persons are withdrawn from that place or zone until the concentration has been reduced so that it is below that level.
(2) The mine operator must ensure that none of the following is taken below ground—
(a)tobacco or other materials for smoking; or
(b)objects used to produce a flame for the purposes of smoking.