30 CFR § 57.6404 - Separation of blasting circuits from power source.

---
identifier: "/us/cfr/t30/s57.6404"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 57.6404 - Separation of blasting circuits from power source."
title_number: 30
title_name: "Mineral Resources"
section_number: "57.6404"
section_name: "Separation of blasting circuits from power source."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "K"
subchapter_name: "METAL AND NONMETAL MINE SAFETY AND HEALTH"
part_number: "57"
part_name: "SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 811."
regulatory_source: "50 FR 4082, Jan. 29, 1985, unless otherwise noted."
cfr_part: "57"
---


# 57.6404 Separation of blasting circuits from power source.

(a) Switches used to connect the power source to a blasting circuit shall be locked in the open position except when closed to fire the blast.

(b) Lead wires shall not be connected to the blasting switch until the shot is ready to be fired.