August 16, 2021 Safety Tip of the Week delivered to your inbox each Monday by GrainnetSafety.com
Engulfment – Bridging Grain
Bridging occurs when grain has a high moisture content, is moldy, or contains foreign material. Grain kernels and foreign material often stick together, forming clumps or a crust on the surface of the grain.
When grain is reclaimed from below, a hollow cavity can form under the bridge or crust. Even though the grain surface looks normal, it cannot support a worker’s weight. If a worker walks onto the surface of the grain, the bridge will collapse, causing the worker to fall into the hollow cavity below.
Grain on the sides of the cavity can bury a worker in seconds. If the reclaim equipment is running, the worker will be pulled deeper into the grain and most likely suffocate.
If entry into a grain storage structure is required, an effective permit process can help ensure that hazards are identified and required safety precautions are implemented including use of specialized entry equipment, atmospheric monitoring, ventilation, lockout tagout, and use of a trained observer.
To prevent grain engulfment:
Never walk on the surface of the grain to restore grain flow within or out of the structure.
Never enter onto or below a bridging condition or where grain is built up on the side of a storage structure.
Never enter a bin when grain is being reclaimed.
Wear a body harness when entering a grain storage structure from a level at or above the level of the stored grain or when walking or standing stored grain. The body harness should be connected a lifeline that is positioned and of sufficient length to prevent the worker from sinking farther than waist deep in grain.
Use an observer, sometimes referred to as an attendant. The observer must be stationed outside of the storage structure and ensure that communications (voice, visual or signal line) are maintained between the observer and the workers inside the structure.
Lock out and tag out equipment that presents a danger to persons inside the grain storage structure.
*For more information on grain bin entry requirements please consult OSHA 29 CFR 1910.272
