Who must inspect a trench and how often?

A competent person — someone able to identify hazards and authorized to correct them — must inspect the excavation daily before workers enter, as conditions change, and after any rain or vibration event. Entry must stop if hazardous conditions are found.

How do workers safely enter and exit a trench?

Trenches four feet or deeper must have a ladder, ramp, or stairway for egress located within 25 feet of any worker, so they never have to travel far to climb out. Jumping or climbing the walls is never acceptable.

Do rain and standing water affect trench safety?

Yes. Water weakens trench walls and increases collapse risk, so workers must not enter a trench with accumulated water unless special precautions like water-removal equipment and continuous monitoring are in place, and a competent person re-inspects after rain.

How accurate is OSHA Scan at detecting trench hazards?

OSHA Scan detects trenching and excavation hazards. It estimates depth and wall condition, checks for protective systems and safe spoil placement, and returns the specific location and OSHA citation.

OSHA Scan

A Cubic Yard of Soil Weighs as Much as a Car

Catch an unprotected trench before anyone climbs in

Trench cave-ins are among the most lethal hazards in construction because they happen without warning and bury workers in seconds under soil that weighs thousands of pounds per cubic yard. An unshored, unsloped trench can collapse from vibration, moisture, or its own weight while a worker is inside. OSHA Scan analyzes excavation photos to flag missing shoring, unsafe sloping, absent trench boxes, and spoil piled too close to the edge before a worker enters.

A trenching and excavation hazard is any trench five feet or deeper — and shallower trenches showing signs of instability — where no protective system such as sloping, benching, shoring, or a trench box is in place, or where soil, water, or spoil placement makes the walls likely to collapse. It shows up as sheer vertical trench walls with a worker inside, a trench box that stops well below the surface, or excavated spoil heaped right at the edge.
In practice, the hazard forms when a crew digs a 'quick' utility trench and skips protection to save time, when a trench box is set too low to protect the working level, or when rain, a nearby road, or vibrating equipment loosens walls that looked stable that morning. Standing water, previously disturbed soil, and underground utilities all compound the danger.
The danger is that a trench can look perfectly solid right up to the instant it fails. There is no groan, no crack, and no time to climb out — a wall shears away and buries a worker before they can react. That sudden, silent collapse is exactly why photo-based detection of trench protection matters.

At what depth does OSHA require trench protection?

OSHA requires a protective system for any trench five feet or deeper unless it is made entirely of stable rock (29 CFR 1926.652). Trenches shallower than five feet may also require protection if a competent person finds signs of a potential cave-in.

What are the accepted trench protective systems?

The main options are sloping or benching the walls to a safe angle, shoring the walls with hydraulic or timber supports, and shielding workers with a trench box. The choice depends on soil type, depth, water, and nearby loads, as determined by a competent person.

Why is spoil placement so important?

Excavated soil, or spoil, piled at the trench edge adds weight that pushes on the walls and can slide back into the trench. OSHA requires spoil, materials, and equipment to be kept at least two feet from the edge to reduce cave-in and struck-by risk.

What are the OSHA penalties for an unprotected trench?

A serious violation of 29 CFR 1926.652 can exceed $16,000 per instance, and willful or repeat violations can top $165,000. Because cave-ins are so often fatal, OSHA treats trenching violations as a national priority and pursues them aggressively.