StacksVerified U.S. regulatory reference

30 CFR §57.6404

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (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.
  2. (b)Lead wires shall not be connected to the blasting switch until the shot is ready to be fired.