Trenching & Excavation

As a contractor, your company likely performs work that involves trenching and excavation. These tasks are extremely dangerous, and without proper precautions they can prove to be deadly. In fact, according to OSHA, two workers are killed every month in trench collapses. Go over this Toolbox Talk with your employees to ensure their safety in all trenching and excavation tasks.

Guidelines for Discussion:

First, let’s go over some basic definitions. An excavation is a cavity in the earth’s surface, intentionally formed via earth removal. A trench is a specific kind of excavation. Trenches are narrow excavations that extend below the surface of the ground. In general, the depth of a trench is greater than the width.

Trenching and excavation are dangerous tasks because they pose the risk of cave-ins. Workers involved in trenching and excavation also risk falls, falling loads, hazardous atmospheres, and vehicle collisions. For these reasons, your company must take extra precautions to only work in protected trenches.

Trench Safety Measures

Trenches with a depth of five feet or more require a protective system unless the excavation is made entirely of stable rock.

Trenches with a depth of twenty feet or more require a protective system that is designed or approved by a registered professional engineer.

If a trench is less than five feet deep, a specialist (known as a competent person) may determine that a protective system is not required. A competent person is a trained individual who is capable of identifying existing and predictable hazards within a work site. A competent person is also authorized to make changes that correct and eliminate any found hazards.

According to OSHA guidelines, a competent person must inspect any and all trenches at the beginning of every workday, and whenever the condition of the trench changes. A competent person must grant approval before any employees enter or perform work involving a trench.

OSHA standards also require safe access (including ladders, steps, ramps, or other means of exit) for employees working in trench excavations that are four feet or deeper. These means of access must be located within twenty-five feet of all workers.