20 Mar Engulfment Hazards

Engulfment Hazards

Engulfment can occur when a worker is surrounded, buried, or submerged by a flowing or collapsing material. Soil, sand, gravel, grain, seed, sawdust, powders, water, chemicals, and other materials can move unexpectedly and trap a worker within seconds.

Engulfment can cause suffocation, drowning, crushing, constriction, or other serious injuries and death. Never enter or work around material capable of engulfing you unless the hazards have been evaluated and proper controls are in place.

Where Engulfment Hazards Occur

Engulfment hazards may be present in:

• Trenches and excavations;
• Grain bins and silos;
• Hoppers and bunkers;
• Tanks and vats;
• Storage bins and containers;
• Piles of soil, sand, gravel, grain, or other loose material;
• Pits, sumps, and similar spaces; and
• Areas where liquids or flowing materials can unexpectedly enter or accumulate.

Many locations with engulfment hazards may also meet the definition of a permit-required confined space, requiring additional entry procedures.

Trenches and Excavations

A cave-in can engulf and crush a worker with little or no warning. Even a relatively small amount of soil can weigh hundreds or thousands of pounds.

Before employees enter an excavation:

• A competent person must inspect the excavation and surrounding conditions as required.
• An appropriate protective system, such as sloping, benching, shoring, or shielding, must be used when required.
• Spoil piles, materials, and equipment must be kept far enough from the edge to prevent material from falling or rolling into the excavation.
• Water accumulation must be controlled.
• Safe access and egress must be provided as required.
• Excavations must be reinspected when conditions change, including after rainstorms or other events that could increase hazards.

Never enter an unprotected excavation when a cave-in hazard exists.

Loose and Flowing Materials

Granular materials can behave much like liquids. Grain, sand, gravel, powders, and similar materials may shift, collapse, or begin flowing when disturbed.

Never walk or stand on accumulated material when there is a possibility that it could collapse, bridge, or flow beneath you.

A particularly dangerous condition occurs when material forms a bridge over an empty space. The surface may appear solid but can collapse under a worker’s weight, resulting in engulfment.

Workers must also stay clear of material being discharged from bins, hoppers, silos, and similar equipment. Flowing material can quickly pull a person downward and make self-rescue impossible.

Bins, Silos, Tanks, and Hoppers

Before entering a bin, silo, hopper, tank, or similar container, determine whether it is a confined space or permit-required confined space.

Before authorized entry:

• Identify and evaluate engulfment and atmospheric hazards.
• Stop the flow of material into and out of the space when necessary for safe entry.
• Lock out/tag out augers, conveyors, agitators, feeders, and other equipment that could move or introduce material.
• Isolate hazardous energy and material sources.
• Test and monitor the atmosphere when required.
• Provide required PPE and retrieval equipment.
• Maintain communication with workers outside the space.
• Follow the applicable confined-space entry procedure.
• Have an appropriate rescue plan established before entry begins.

Never rely on a coworker simply standing outside the space as the entire rescue plan.

Preventing Engulfment

The safest approach is to eliminate the need for employees to enter or stand on materials that could engulf them.

When exposure cannot be eliminated:

• Identify the hazard before work begins.
• Use engineering controls to prevent material movement.
• Isolate equipment and energy sources.
• Prevent unexpected introduction of liquids or materials.
• Use fall protection or retrieval systems when required.
• Restrict access to authorized and properly trained employees.
• Maintain reliable communication.
• Establish emergency and rescue procedures before beginning work.

Rescue

Never enter an engulfment situation to attempt an unplanned rescue.

A second worker entering a bin, excavation, tank, or other hazardous area without proper equipment and procedures can quickly become another victim.

Immediately initiate the site’s emergency procedures and summon the designated rescue service. Only properly trained, equipped, and authorized personnel should perform entry rescue.

Remember

Engulfment can happen quickly, and once a worker is trapped, self-rescue may be impossible.

Never enter a trench, bin, silo, hopper, tank, pile of loose material, or other engulfment hazard until the conditions have been evaluated and the required protective measures are in place.

Control the material, isolate the energy, follow established procedures, and plan the rescue before the work begins—not after an emergency occurs.