The Hazards of Leading Edges – Part II: Excavation

This week we’ll look at leading edge hazards in excavation work. OSHA regulates hazardous elevations starting at 48 inches (four feet) in general industry, and 72 inches (6 feet) in construction. However, proactive safety management programs look for leading edge hazards at any height and create plans to protect workers.

The leading edge of an excavation project poses several potential injury scenarios, including falls and cave-ins. The danger to workers and equipment is great if the edge warning is limited or non-existent. Devastating impact injuries occur from falling into excavation holes, especially if the worker lands on an object, such as a concrete pipe or concrete forms.

Never pile excavated material (spoils) too close to the edge of a trench/excavation. It obscures the view of the edge, which makes it possible for equipment to drive off the edge and into the excavation.

Soil at the leading edge of an excavation site has a low, unconfined compressive strength, meaning the soil does not have anything to push against when it is compressed. An edge with low compressive strength can result in the soil giving way, and anyone or anything at that edge will cascade into the hole.

Provide leading edge protection on an excavation site by doing one or more of the following:

  • Use snow fencing or other visual warning material to create a warning barrier.
  • Set spoils and equipment at least two feet from the excavation.
  • Where the site does not permit a two-foot set back of materials, temporarily haul spoils to another location.

Leading edges exist in all types of construction. Make sure your jobsite safety audit includes an inspection of all leading edges and provides a plan of action for protecting workers.