On average, two workers are killed every month in trench collapses. To ensure your health and safety, it’s important for employees to have an understanding of various rules related to trenching and excavating safety.

Let’s examine some of the trenching and excavating rules by the numbers:

1. The 18-inch rule—In situations where sloping is being used in combination with protective systems, but the protective system does not reach ground level, shoring or shielding must extend a minimum of 18 inches above the vertical side of the trench.
2. The 2-foot rule—Those working around a trench must keep soil piles and heavy equipment at least 2 feet away from the edge of trenches. This helps to prevent cave-ins and crushing injuries.
3. The 4-foot rule—For your safety, access and egress to all excavations will be provided, including ladders, steps, ramps or other safe means of exit for employees working in trench excavations 4 feet or deeper. These devices will be located within 25 feet of you at all times to ensure you can exit a trench quickly in an emergency.
4. The 5-foot rule—Trenches 5 feet deep or greater require a protective system, unless the excavation is made entirely in stable rock. Protective systems are determined by the designated competent person and refer to sloping, shoring and shielding. If the trench is less than 5 feet deep, a competent person may determine that a protective system is not required. If you have questions regarding who the employer-designated competent person is, ask your supervisor.
5. The 20-foot rule—Trenches 20 feet deep or greater require protective systems designed by a registered professional engineer.

While it’s the competent person’s responsibility to do formal inspections of the trenches, employees should speak up if they notice worksite issues.

For questions related to trenching and excavating safety, speak to your supervisor.