Hazards: Electric shock and electrocution from a damaged cord · Ground path lost through a missing ground prong · Fire from an overheated or pinched cord · Trip and fall from cords in walkways
Why it matters
Ordinary voltage is what hurts most people. Of nonfatal direct-contact electrical injuries in construction from 2011 to 2019, only 15.1% involved more than 220 volts — the rest happened at the voltage running through every cord on this site (BLS survey data, CPWR Data Bulletin, November 2022).
On April 9, 2022, a worker digging under a house plugged a drop light into his extension cord to see better (OSHA Accident Search, Summary Nr 145407.015). The light had cuts in its cord, a missing ground pin and a failed strain relief. He plugged his chipping hammer into that light and was electrocuted. Every one of those defects is on the list you look for before the shift.
Key points
- Look at every cord before the day's use. 1926.404(b)(1)(iii)(C) and 1910.334(a)(2)(i): check for external defects — deformed or missing pins, cut jacket, loose parts.
- Read the jacket. 1926.405(g)(2)(ii): S, SO, ST, SJ and the rest must be durably marked with type, size and number of conductors. An unmarked household cord is not jobsite cord.
- Taped splices are not repairs. (g)(2)(iii): cords are used in continuous lengths without splice or tap. Only hard service cord No. 12 or larger may be repaired, and the splice must restore insulation and outer sheath.
- Pull the plug, not the cord. (g)(2)(iv) requires strain relief so tension never reaches the terminals. A plug that spins or shows copper has already lost it.
- Cord is not building wiring. (g)(1)(iv): not through walls, ceilings, floors, doorways or windows, not fastened to the building. 1926.416(e)(2): no staples, no nails, no wire.
- Bad cord leaves today. 1926.416(e)(1): worn or frayed cords shall not be used. Cut the plug off and bin it, or it comes back out of the gang box tomorrow.
Do / Don't
Do
- Lay the cord out flat and run it through your hands before you plug it in.
- Route it overhead or along a wall, hung on non-conductive hooks.
- Keep every cord out of standing water, mud and drive lanes.
- Tag and remove any cord you would not want your own hands on.
Don't
- Cut off a ground prong to make a plug fit.
- Tape over a nick and keep using the cord.
- Daisy-chain three light-duty cords to reach the far corner.
- Hang a cord on a nail or staple it to a stud.
Quick site check
- Empty the gang box, lay every cord out and pull the failures now — before someone needs one in a hurry.
- Walk the run from the receptacle to the tool: doorways, standing water, pinch points under a plate or a wheel.
- Check the plug ends for missing prongs, cracked bodies, and a jacket that still grips the plug.
- Pick up the cord closest to you right now and look at the plug end: all three prongs, no cracks, no tape over a splice?
- Where on this site are we running cord through a doorway, a window, or a hole in a wall today?
- Who inspected the cords in the gang box before this shift, and what did they do with the bad ones?
- If you found a cord with a cut jacket right now, where would you put it so nobody plugs it back in an hour from now?
- Are the cords we are using marked S, SO, ST or SJ on the jacket, or did somebody bring a household cord from home?