OSHA's excavation regulations for construction activities cover the safe work practices employees and supervisors must follow at excavation sites. OSHA requires employers to use a protective system in all excavations and trenches 5 feet (ft) or deeper to protect employees exposed to potential cave-ins and other related hazards. Since cave-ins at excavations present the greatest threat of injury or death to workers, the regulations contain detailed appendices on soil types and approved protective systems such as sloping, shoring, and the use of shields.
The rules also require extensive training for the "competent person" who must daily inspect and oversee excavation and trenching operations. Finally, they provide performance criteria for protective systems that are required when there is risk of a cave-in.
The most common causes of trenching and excavation accidents include:
- No protective systems in place
- Failure to inspect the trench and protective systems
- Unsafe placement of the spoil pile
- Unsafe entry and exit to and from the trench
Other hazards and site conditions regulated by the excavation standards include:
- Underground installations
- Surface vehicular traffic and obstacles
- Adjacent structures
- Entry and exit
- Rainfall, runoff, and standing water
- Hazardous atmospheres (confined spaces)
- Equipment for moving and unloading
- Installation and removal of the protective systems
The excavation rules. The excavation rules for construction are located at 29 CFR 1926 Subpart P, specifically:
- 29 CFR 1926.650—Scope, application, and definitions
- 29 CFR 1926.651—Specific excavation requirements (hazard removal or support to safeguard employees)
- 29 CFR 1926.652—Protective systems (sloping, benching, shoring, and shielding)
- 29 CFR 1926 Subpart ...