Electrical Safety
De-energize First
1910.333(a) requires live parts to be deenergized before employees work on or near them unless de-energizing introduces an additional or increased hazard, or is infeasible because of equipment design or operational limitations. Once de-energized, apply lockout/tagout under 1910.147, verify the absence of voltage with a tester rated for that voltage, and treat the circuit as energized until verification is complete.
Qualified vs. Unqualified Persons
1910.332 requires training for any employee exposed to electrical hazards; qualified persons receive additional training on specific hazards and safe work practices. Unqualified persons must keep at least 10 feet from exposed live parts up to 50 kV. Qualified persons may work closer, using the minimum approach distances in the standard's table plus appropriate PPE, and only when necessary.
Cords, Tools, and GFCIs
Flexible cords may not be used as permanent wiring, spliced, run through doorways or walls, or daisy-chained; damaged cords are removed from service; grounding pins are never removed. Portable tools must be grounded or double-insulated and inspected before use. Ground-fault circuit interrupter protection (tripping in the range of about 5 milliamps) is required for temporary receptacles and construction receptacles.
Traps and a Rule of Thumb
Traps: blending 1910.147 lockout/tagout with 1910.333 work practices; assuming lockout is always required (cord-and-plug equipment unplugged and under exclusive control is an exception); assuming rubber gloves alone make live work acceptable; mixing up 10 feet (unqualified) with closer qualified-person distances.
Rule of thumb: de-energize, lock, tag, test, then touch - never the reverse.