Many risks involved with working in and around trenches. The following measures should be taken to control the risk of cave-ins and other potential hazards associated with trenching operations, including:
• According to OSHA (Occupational Safety and Health Administration), trenches 5 ft. (1.5 meters) deep or greater
require a protective system unless the excavation is made entirely in stable rock. If less than 5 feet deep, a
competent person may determine that a protective system is not required
• Trenches 20 ft. (6.1 meters) deep or greater require that the protective system be designed by a
registered professional engineer or be based on tabulated data prepared and/or approved by a registered
professional engineer in accordance with 1926.652(b) and (c)
• Trenches should be inspected daily and as conditions change by a competent person before worker entry to
ensure elimination of excavation hazards
• All excavations should have safe access and egress, including ladders, steps, ramps, or other safe means of exit for
employees working in trench excavations 4 feet or deeper
• Keep heavy equipment away from trench edges
• Identify other sources that might affect trench stability
• Keep excavated soil (spoils) and other materials at least 2 feet from trench edges
• Call OKIE811 to locate lines before digging
• Test for atmospheric hazards such as low oxygen, hazardous fumes and toxic gases when > 4 feet deep
• Inspect trenches before beginning a new job and at the start of each shift and after any other occurrence that
could have changed the trench conditions
• Inspect trenches after rain
• Do not work under suspended loads
• Wear high visibility or other suitable clothing when exposed to vehicular traffic
