29 CFR 1926.910 : Labor (§ 0.735-1 To Parts 4908-4999) — (§ 1926.1 To Appendix A To Part 1926) — Regulations Relating To Labor (Continued) (§ 1926.1 To Appendix A To Part 1926) — Occupational Safety And Health Administration, Department Of Labor (Continued) (§ 1926.1 To Appendix A To Part 1926) — Safety And Health Regulations For Construction (§ 1926.1 To Appendix A To Part 1926) — Blasting And The Use Of Explosives (§ 1926.900 To § 1926.914) — Inspection after blasting.

(a) Immediately after the blast has been fired, the firing line shall be disconnected from the blasting machine, or where power switches are used, they shall be locked open or in the off position.

(b) Sufficient time shall be allowed, not less than 15 minutes in tunnels, for the smoke and fumes to leave the blasted area before returning to the shot. An inspection of the area and the surrounding rubble shall be made by the blaster to determine if all charges have been exploded before employees are allowed to return to the operation, and in tunnels, after the muck pile has been wetted down.