Home / Standards guides / Trenching and Excavation Safety for Workers (Caught-In/Between)

Black Belt Safety · Free guide

Trenching and Excavation Safety for Workers (Caught-In/Between)

For workers who enter or work around trenches and excavations: when cave-in protection is required, how to get in and out safely, the hazards at the edge and in the hole, and what to do when conditions change.

Based on OSHA 29 CFR 1926 Subpart P (1926.650–1926.652) · about 5 min read

Need proof of training? The full course (20 min) adds practice questions, a job scenario, the final quiz and a certificate your employer can verify.

Take the course

When protection is required

Cave-ins and the 5-foot rule

These rules apply to all open excavations in the earth's surface, including trenches. A trench is a narrow excavation: in general deeper than it is wide, and no more than 15 feet wide at the bottom.

A cave-in is when soil or rock separates from the side of an excavation, or soil is lost from under a trench shield or support system, and moves suddenly into the hole in enough quantity to trap, bury, or otherwise injure and immobilize a person.

The rule

Every worker in an excavation must be protected from cave-ins by an adequate protective system, except when:

The excavation is made entirely in stable rock, or
It is less than 5 feet deep and a competent person has examined the ground and found no sign of a possible cave-in.

Remember: under 5 feet is not automatically safe. It still takes a competent person's examination.

Reference: 29 CFR 1926.650(a) · 29 CFR 1926.650(b) "Cave-in" · 29 CFR 1926.650(b) "Trench (Trench excavation)" · 29 CFR 1926.652(a)(1)

When protection is required

Protective systems you will see

There are four main types of protective system you will see. Learn to recognize each one.

◢

SlopingThe sides are cut back at an angle, away from the excavation. Unless the employer uses another allowed method, the slope can be no steeper than 1½ horizontal to 1 vertical (34 degrees from horizontal).

▟

BenchingThe sides are cut into one or more horizontal levels or steps.

╫

ShoringA structure, such as a metal hydraulic, mechanical or timber shoring system, that supports the sides of the excavation to prevent cave-ins.

▭

Shield (trench box)A structure strong enough to withstand a cave-in and protect the workers inside it. In trenches, often called a trench box or trench shield.

Reference: 29 CFR 1926.650(b) "Protective system" · 29 CFR 1926.650(b) "Sloping (Sloping system)" · 29 CFR 1926.650(b) "Benching (Benching system)" · 29 CFR 1926.650(b) "Shoring (Shoring system)" · 29 CFR 1926.650(b) "Shield (Shield system)" · 29 CFR 1926.652(b)(1)(i)

Getting in and out

Ladders, ramps and trench boxes

A way out within 25 feet

In trenches 4 feet or more deep, there must be a stairway, ladder, ramp or other safe way out located so you never have to travel more than 25 feet sideways to reach it.

Trench boxes

You must be protected from cave-ins while entering and leaving the area a shield protects.
Stay out of a shield while it is being installed, removed or moved vertically.

Crossing over

Use a walkway to cross an excavation where crossing is required or permitted. Walkways 6 feet or more above the lower level need guardrails.

Reference: 29 CFR 1926.651(c)(2) · 29 CFR 1926.652(g)(1)(iii) · 29 CFR 1926.652(g)(1)(iv) · 29 CFR 1926.651(l)

Hazards at the edge and in the hole

At the edge

Spoil and materials: excavated soil, materials and equipment must be kept at least 2 feet from the edge, or held back by retaining devices, or both, so they cannot fall or roll in.
Loads: never stand under loads handled by lifting or digging equipment. Stand away from any vehicle being loaded or unloaded so spillage or falling material cannot hit you.
Traffic: if you are exposed to public traffic, you must be given and must wear a warning vest or other garment made of or marked with reflective or high-visibility material.
Equipment near the edge: when mobile equipment works next to an excavation or approaches its edge, and the operator cannot clearly see the edge, a warning system such as barricades, hand or mechanical signals, or stop logs must be used.
Utilities: the estimated location of underground utilities must be determined before the excavation is opened.

Reference: 29 CFR 1926.651(j)(2) · 29 CFR 1926.651(e) · 29 CFR 1926.651(d) · 29 CFR 1926.651(f) · 29 CFR 1926.651(b)(1)

Hazards at the edge and in the hole

In the hole: water and bad air

Water

Do not work in an excavation where water has collected or is collecting unless adequate precautions have been taken to protect you from the hazards of that water.

Air

Where low oxygen (less than 19.5 percent) or a hazardous atmosphere exists or could reasonably be expected, such as in landfill areas or near stored hazardous substances, the air must be tested before anyone enters an excavation deeper than 4 feet.

Where hazardous air exists or may develop, emergency rescue equipment, such as breathing apparatus, a safety harness and line, or a basket stretcher, must be readily available.

Reference: 29 CFR 1926.651(h)(1) · 29 CFR 1926.651(g)(1)(i) · 29 CFR 1926.651(g)(2)(i)

When conditions change

Inspections, and getting out

A competent person must inspect the excavation, the area around it and the protective systems every day that workers can be expected to be exposed, looking for signs of a possible cave-in, failing protective systems, hazardous air or other hazards.

Before work starts
As needed during the shift
After every rainstorm or other event that increases the hazard

When the competent person finds one of those hazards, exposed workers must be removed from the hazardous area until the needed precautions are in place.

If shoring, a shield or other protective equipment is damaged, a competent person must examine it before it stays in use.

A good practice is to tell the competent person right away about anything you notice, such as cracks at the edge, water seeping in, or a damaged trench box, and to get out of the hole until they have looked at it.

Reference: 29 CFR 1926.651(k)(1) · 29 CFR 1926.651(k)(2) · 29 CFR 1926.652(d)(3)

Need proof of training? The full course (20 min) adds practice questions, a job scenario, the final quiz and a certificate your employer can verify.

Take the course

Sources

29 CFR 1926 Subpart P

Fact-checked against the regulation text on October 09, 2026. This certificate records completion of awareness training based on OSHA 29 CFR 1926.650, 1926.651 and 1926.652. It is not an OSHA card or license, and it does not make anyone a competent person. Subpart P has no training paragraph of its own, and this certificate does not by itself meet the general training requirement of 29 CFR 1926.21(b)(2). Your employer must still instruct you in the recognition and avoidance of unsafe conditions and the regulations applicable to your work environment to control or eliminate any hazards.

This guide explains the rule in plain words. Always read the regulation itself and your employer's site-specific procedures.