Section 190(5)(c) in The Coal Mines Regulations, 2017
(c)the assistance, if any, available to him in the performance of his said duties; 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 multishot exploder is used;(iii)in the case of opencast 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: