Grain storage bins and hoppers pose severe hazards, including entrapment and suffocation. Each year, numerous people suffocate and die while working on or under the unstable materials contained in grain silos. Grain materials are unpredictable and they move quickly — entrapment, burial, and suffocation can occur within seconds.

In some cases, the surface material in a grain bin acts like quicksand. When a storage bin is emptied from the bottom, the grain material forms a funnel. The flow rate of this funnel can be strong enough to trap a worker and make rescue virtually impossible.

In other cases, a condition known as bridging can create serious hazards. A bridge occurs when grain or other loose material sticks to the side of a bin that is being emptied from below. The bridge is highly unstable and dangerous. If it collapses, it can trap any worker either on or below it.

Follow these guidelines to reduce the risks associated with grain storage:

• Assume that all stored materials are bridges and that the potential for entrapment and suffocation is constant.
• Do not enter a storage area from the bottom if material is adhering to the sides.
• If you must enter a storage area, use a safety belt or h arness with a lifeline. Always stay above the highest level of material. Never stand on top of stored material.
• Lock out supply and discharge equipment whenever a worker enters the storage area.
• Post signs that indicate the hazards of working with stor ed materials.
• Ensure that storage areas are equipped with mechanical devices so that workers are not required to enter the area.