Working Safely in Trenches

Source: Tracy Fox - 123RF

Trench fatalities are a serious problem in construction.  Bureau of Labor Statistics data shows that about 25 workers are killed each year in trench-related mishaps. 

Cave-ins cause about three out of every four fatalities; the remainder are commonly due to struck-bys or electrocutions.

According to the Laborers’ Health and Safety Fund of North America (LHSFNA), in 2003, the nation experienced a spike in trench fatalities (53, according to preliminary data, later reduced to 48), inviting a detailed OSHA investigation which highlighted important facts about trench dangers. 

Following its investigation, OSHA undertook a national emphasis campaign, distributing more information about trench hazards and stepping up enforcement.  As a result, annual trench fatalities declined.

According to OSHA, the primary hazard of trenching and excavation is employee injury from collapse. Soil analysis is important in order to determine appropriate sloping, benching, and shoring.

Additional hazards include:

  • Working with heavy machinery;
  • Manual handling of materials;
  • Working in proximity to traffic;
  • Electrical hazards from overhead and underground power-lines; and
  • Underground utilities, such as natural gas.

When done safely, trenching operations can reduce worker exposure to cave-ins, falling loads, hazardous atmospheres, and hazards from mobile equipment.

The following references aid in recognizing and controlling some of the hazards associated with trenching and excavation: