If there are any misfires while using cap and fuse, all persons shall remain away from the charge for two hours. If electric blasting caps are used, the waiting period may be reduced to thirty minutes. Misfires shall be handled under the direction of the person in charge of the blasting and all wires shall be carefully traced and a search made for unexploded charges. (Ord. 65-105. Passed 6-1-65.)