In the United States, trench and excavation hazards cause more than 100 deaths and 1,000 injuries every year. Eventually, all excavations and trenches will cave-in, but knowing proper safety procedures and what hazards to watch for will greatly reduce the risk of injury.

The National Utility Contractor’s Association (NUCA) is holding a safety stand down week for trench and excavation safety from June 18-23. This event, endorsed by OSHA, provides companies with an opportunity to have a conversation with employees about trench and excavation hazards and best practices to prevent injury. Take a break to talk about trench and excavation safety, plan a safety event or provide training for all workers.

Cave-ins pose the greatest risk and are much more likely than other excavation-related accidents to result in worker fatality. Keep an eye out for warning signs, such as bulges in the walls of the excavation and cracks running parallel to the edge.

Other trench and excavation risks include:

• Asphyxiation due to lack of oxygen
• Inhalation of toxic materials
• Exposed utility lines, underground and overhead
• Falling objects
• Water in the excavation
• Moving machinery near the edge of the excavation could cause a collapse
• Vehicle traffic

Trench and excavation safety recommendations

When doing trenching and excavation work, a competent person capable of identifying and correcting hazards and who has the authority to stop work must be present. Prior to beginning work, underground utilities should be located. Before an employee enters the excavation, test the area for hazardous atmospheres such as oxygen deficiency and high concentration of combustible gas or other hazardous substances. If detected, clear away prior to entry.

Depending on the depth of a trench, different safety requirements are necessary. Access or egress must be provided for an excavation of four feet or greater. If an excavation is more than five feet then a protective system of either a bench, slope or shield must be in place. When the excavation exceeds six feet, fall protection is required.

Examine equipment used for protective systems for damage that could impair its function. Remove and replace damaged equipment.

Spoil piles should be a minimum of two feet away from an excavation’s edge and placed so that rainwater runs away from the excavation. Ladders are required to enter or exit a trench and must be within 25 feet of all workers. Employees should not work outside of a trench box or shoring. All workers need appropriate personal protection equipment: hard hats, safety boots, safety glasses and Class II high visibility vests.

By following these safety recommendations and keeping aware of your surroundings, you can significantly reduce the risk of injury.

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