Section 194(5)(d) in The Coal Mines Regulations, 2011
(d)any other duties assigned to him, whether statutory or otherwise, and shall not in any case exceed-(i)in the case of a gassy seam of second or third degree or a fiery seam, forty, if a single shot exploder is used and eighty; if a multi-shot exploder is used;(ii)in the case of other seams fifty, if a single-shot exploder is used and hundred, if a multi-shot exploder is used; and(iii)in the case of open cast mines sixty, if a single shot exploder is used or if blasting is done with ordinary detonators and one hundred and twenty, if a multi-shot exploder is used: