U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 28, 2025
When a misfire is suspected, persons shall not enter the blast area—
(a) For 30 minutes if safety fuse and blasting caps are used;
(b) For 15 minutes if any other type detonators are used; or
(c) For 30 minutes if electronic detonators are used, or for the manufacturer-recommended time, whichever is longer.