OSHA Trenching and Excavation Safety Questions & Answers Part 1 Introduction
OSHA defines an excavation as any man-made cut, cavity, trench, or depression in the Earth’s surface formed by earth removal. A trench is defined as a narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth of a trench is greater than its width, but the width of a trench (measured at the bottom) is not greater than 15 feet (4.6 m).
2) What are the dangers of trenching and excavation operations?
Trenching and excavation work presents serious hazards to all workers involved. Cave-ins pose the greatest risk and are more likely than some other excavation-related incidents to result in worker fatalities. One cubic yard of soil can weigh as much as a car. An unprotected trench can be an early grave. Employers must ensure that workers enter trenches only after adequate protections are in place to address cave-in hazards. Other potential hazards associated with trenching work include falling loads, hazardous atmospheres, and hazards from mobile equipment.
3) What do the OSHA Excavation standards cover, and how do they protect workers?
The standards apply to all open excavations made in the Earth’s surface, including trenches. Following the requirements of the standards will prevent or greatly reduce the risk of cave-ins and other excavation-related incidents.
4) What are the soil classification categories?
Some of the compliance methods permitted under the Excavation standards require a competent person to classify soil and rock deposits as:
- Stable rock;
- Type A soil;
- Type B soil;
- Type C soil.
5) What is a competent person?
A competent person is an individual, designated by the employer, who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous or dangerous to workers, and who is authorized to take prompt corrective measures to eliminate them.
Under the Excavation standards, tasks performed by the competent person include:
- Classifying soil;
- Inspecting protective systems;
- Designing structural ramps;
- Monitoring water removal equipment; and
- Conducting site inspections.