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Home / OSHA / Excavation & Trenching

OSHA Trenching Requirements — The 5-Foot Rule, Sloping & Egress

Excavation work is governed by 29 CFR 1926 Subpart P. The controlling number is 5 feet: any trench 5 feet or deeper requires a protective system — sloping, benching, shoring, or a trench shield — unless it is entirely in stable rock.

RequirementOSHA StandardSection
Protective system trigger5 ft depth (any depth if a competent person sees signs of cave-in hazard)1926.652(a)(1)
EgressLadder, stairway, or ramp within 25 ft of lateral travel in trenches 4 ft or deeper1926.651(c)(2)
Spoil setbackExcavated material and equipment kept at least 2 ft from the edge1926.651(j)(2)
Maximum slopesType A soil 3/4:1 (53°) · Type B 1:1 (45°) · Type C 1 1/2:1 (34°)1926.652 App. B
Deep excavations20 ft or deeper: protective system designed by a registered professional engineer1926.652(b)(4), (c)(4)
InspectionsDaily by a competent person before work starts, and after rain or other hazard-changing events1926.651(k)(1)
Hazardous atmospheresAir testing before entry in excavations over 4 ft deep where a hazardous atmosphere could reasonably be expected1926.651(g)(1)
UtilitiesLocate underground installations before digging (call 811); support or protect exposed lines1926.651(b)

Worth knowing

  • If a competent person has not classified the soil, it must be treated as Type C — the flattest slope.
  • Water accumulation requires special precautions: removal equipment monitored by a competent person (1926.651(h)).
  • A trench box does not eliminate the depth rules — workers may not be in the shield during installation or removal, and the shield must extend per manufacturer tabulated data.
  • Trench collapses are consistently among the deadliest construction incidents — a cubic yard of soil weighs about 3,000 lb.
Source: 29 CFR Part 1926, Safety and Health Regulations for Construction (U.S. Department of Labor, public domain) — read the full standard at osha.gov. State-plan states may impose stricter rules, and your local building code applies in addition — find it on your jurisdiction page.
Fall Protection →Ladders & Stairways →Scaffolds →