Trench Safety: Simple Rules That Prevent the Worst
Most trench incidents don’t give a warning. Walls can fail in seconds, and even a shallow cave-in can be fatal. The good news: the biggest risks are well understood and preventable.
1) Protect against cave-ins
Use one of the three protective systems any time you’re at risk: sloping/benching, shoring, or a trench box (shielding). OSHA requires a protective system for excavations 5 feet or deeper unless you’re in stable rock and a competent person confirms no cave-in hazards. When in doubt, protect it. eCFR
2) Safe ways in and out
If a trench is 4 feet or deeper, provide a ladder, stairway, ramp, or other safe egress. Workers in the trench shouldn’t have to travel more than 25 feet to reach it. OSHA+1
3) Keep weight off the edge
Set spoil piles, materials, and equipment at least 2 feet back from the trench lip, and keep heavy machinery away from edges that could undermine the walls. OSHA
4) Inspect—every shift and after changes
A competent person should inspect trenches, adjacent areas, and protective systems daily before work and after events like rain, vibration, or other conditions that could destabilize the trench. If conditions change, stop and reassess. OSHA
5) Know what’s underground and what’s in the air
Locate utilities before digging, and test the atmosphere when there’s a reasonable chance of a hazardous environment (e.g., landfills/contaminated soil) — particularly for excavations deeper than 4 feet. OSHA+1
Quick field checklist
Protective system in place (slope, shore, or shield) as required. eCFR
Spoils/materials set back 2+ feet; equipment kept off edges. OSHA
Ladder/stair/ramp within 25 lateral feet in trenches ≥4 ft deep. OSHA
Daily inspection by a competent person; re-inspect after rain/vibration. OSHA
Utilities located and marked; hazardous atmospheres considered/tested. OSHA+1
Why it matters
Every year, workers are killed or seriously injured in trench collapses — events that are entirely preventable when these basics are followed. If you lead a crew, make trench protection non-negotiable and empower your competent person to pause work when conditions change. CDC