CSLB C-36 Plumbing ContractorSafetyEasy
A plumbing contractor is tasked with repairing a burst water pipe in a trench that is 5 feet deep and 3 feet wide. The soil is stable clay. According to OSHA regulations, what is the minimum requirement for trench protection in this scenario?
- AInstalling a trench box or shoring system.
- BOnly a ladder for egress is required.
- CNo protective system is required as the trench is less than 6 feet deep.
- DSloping the trench walls to a 1.5:1 ratio (horizontal to vertical).
Show answer & explanationAnswer & explanation
Correct answer: C. No protective system is required as the trench is less than 6 feet deep.
OSHA regulations, specifically 29 CFR 1926.652(a)(1), state that each employee in an excavation 5 feet (1.52 m) or more in depth shall be protected from cave-ins by an adequate protective system, unless the excavation is made entirely in stable rock or is less than 5 feet in depth and a competent person determines that there is no indication of a potential cave-in.
Why the other options are wrong
- A. Trench boxes or shoring are protective systems, but they are not the minimum requirement if the trench is 5 feet deep and deemed safe by a competent person.
- B. Egress is a separate safety requirement; it does not substitute for cave-in protection.
- D. Sloping is one type of protective system, but the question asks about the minimum requirement. For a 5-foot trench, if a competent person determines there's no risk, no system is needed.
OSHA Trench Protection Depth
OSHA mandates protective systems for trenches 5 feet (1.52 m) or deeper, unless a competent person determines that trenches less than 5 feet deep pose no cave-in risk.
- 5 feet or more in depth requires protection.
- Less than 5 feet deep may not require protection if deemed safe by a competent person.
- Protective systems include sloping, shoring, and trench boxes.
Memory trick: Five feet or more, make sure the trench is secure, or risk a safety roar!