Trenching and cave-ins

Key points

1. 1Any trench 5 feet deep or more needs a protective system: sloping, benching, shoring, or a trench box. Don't trust the soil just because it looks solid.
2. 2The competent person inspects the trench before work starts each day, after rain, and after anything changes. If they haven't checked it, you don't go in.
3. 3Keep spoil piles, tools, and materials at least 2 feet back from the edge. Keep heavy equipment back too, because its weight and vibration can bring the wall down.
4. 4In trenches 4 feet or deeper, there must be a ladder or ramp within 25 feet of where you are working. Know your way out before you need it.
5. 5Stay inside the trench box or shored area. Never stand outside the protection, even for a minute, and never ride the box while it's being moved.
6. 6Watch for warning signs: cracks along the edge, water seeping in, bulging walls, or dirt falling. If you see any of these, get out and tell the foreman right away.
7. 7Never stand under a loaded bucket or near the excavator swing. Stay clear while loads are lifted or dumped.

Talk it over

• Who is the competent person on our site, and how do you know they checked the trench today?
• Where is the closest ladder or ramp out of the trench you're working in right now?
• What would you do if you saw a crack open up along the edge while someone was down in the trench?

Also in the other language: Zanjas y derrumbes

Official sources

• 29 CFR 1926.651 — Excavations — specific requirementsecfr.gov
• 29 CFR 1926.652 — Requirements for protective systemsecfr.gov

More toolbox talks

• Safe lifting and back care
• Silica dust
• Struck-by hazards