30 CFR § 56.6310 - Misfire waiting period.
(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.
The following state regulations pages link to this page.