Section 141(4)(c) in The Coal Mines Regulations, 2011
(c)there shall be kept available, at or near all places belowground:(i)adequate number of self-rescuers and at least two smoke helmets or other suitable apparatus for use in emergency;(ii)an apparatus for detecting carbon monoxide gas approved by the Chief Inspector; and(iii)a flame safety lamp or other means of detecting carbon dioxide gas and oxygen deficiency, approved by the Chief Inspector.