Engulfment and Suffocation HazardsGrain storage bin entry is very dangerousand exposes workers to serious suffocationhazards - a leading cause of fatalities in thisindustry. Suffocation can occur when work-ers are engulfed (buried or covered) by grainor when bins develop hazardous atmos-pheres or a lack of oxygen.

Engulfment can occur when a worker doesthe following:

• Stands on moving/flowing grain (see fig-ure 1) – The moving grain acts like “quick-sand” and buries the worker in seconds.

• Stands on or below a “bridging” condition(see figure 2) - “Bridging” occurs whengrain clumps together, because of moistureor mold, creating an empty space beneaththe grain as it is unloaded. If a workerstands on or below the “bridged” grain, itcan collapse, either under the worker’sweight or unexpectedly, thus, burying theworker.

• Stands next to an accumulated pile of grainon the side of the bin (see figure 3) – Thegrain pile can collapse onto the workerunexpectedly or when the worker attemptsto dislodge it.

The grain’s behavior and weight make itextremely difficult for a worker to get out ofthe grain without assistance. Tragically, inci-dents in grain bins often result in multiplefatalities because coworkers attempt rescueand fall victim as well. These fatalities arepreventable if employers follow work prac-tices and provide training and equipmentas required by OSHA’s Inspection of GrainHandling Facilities standard, 29 CFR 1910.272.

Where Workers Enter Storage Bins,Employers Must:• De-energize (turn off) and disconnect, lock-

out and tag, or block off all mechanical,electrical, hydraulic and pneumatic equip-ment that presents a danger, particularlygrain-moving equipment. Grain must notbe emptied or moved into or out of the bin

FactSheetWorker Entry intoGrain Storage Bins

From the time theauger starts, youhave 2-3 secondsto react.

In 4-5 secondsyou are trapped!

After 22 seconds,you are completelycovered.

Figure 1. Flowing grain can bury a worker in seconds.

A dangerous situa-tion created by aprevious partialunloading of the bin.

As unloading begins,bridged grain fallsinto the air spaceand the worker isinstantly trapped.

Before the grainflow can be stopped,the worker is cov-ered. In seconds,suffocation occurs.

Figure 2. “Bridging” condition that results in engulfment.

Beware of a steeppile of grain...

because it maytumble down...

and result insuffocation.

Figure 3. Accumulation on bin side that results in engulfment.

The person on theinside of the bin issecured to the out-side of the bin.

The person on theroof can passinstructions andassist in lifting.

The person on theground can go forhelp or assist inpulling.

Figure 4. Illustration of successful rescue of worker during“bridging” condition.

while workers are inside because it createsa suction that can pull the worker into thegrain in seconds.

• Prohibit walking down grain and similarpractices where a worker walks on grain tomake it flow.

• Prohibit entry onto or below a bridgingcondition, or where grain is built up on theside of the bin.

• Provide each worker entering a bin from alevel at or above stored grain, or when aworker will walk or stand on stored grainwith a body harness with a lifeline, or aboatswain’s chair. Ensure that the lifeline ispositioned and of sufficient length to pre-vent a worker from sinking further thanwaist-deep in grain.

• Provide workers with rescue equipment,such as winch systems that are specificallysuited for rescue from the bin (see figure 4).

• Station an observer who is equipped toprovide assistance and perform rescueoperations outside the bin (see figure 4).

• Ensure that communications (visual, voiceor signal line) are maintained between theobserver and the workers who entered thebin.

• Test the air within a bin for oxygen contentand the presence of hazardous gasesbefore entry.• Provide and continue ventilation until

any unsafe atmospheric conditions areeliminated.

This is one in a series of informational fact sheets highlighting OSHA programs, policies orstandards. It does not impose any new compliance requirements. For a comprehensive list ofcompliance requirements of OSHA standards or regulations, refer to Title 29 of the Code of FederalRegulations. This information will be made available to sensory impaired individuals upon request.The voice phone is (202) 693-1999; teletypewriter (TTY) number: (877) 889-5627.

• If toxicity or oxygen deficiency cannot beeliminated, workers must wear appropriaterespirators.

• Issue a permit each time a worker enters abin, unless the employer is present duringthe entire entry operation. The permit mustcertify that the above precautions havebeen implemented before workers enterthe bin.

© 2002, University of Kentucky Cooperative ExtensionService. Images reproduced with permission.

Additional Guidance• For additional information on safe work

practices in grain handling facilities, pleasesee:• 29 CFR 1910.272, Inspection of Grain

Handling Facilities.• OSHA’s Grain Handling Safety and Health

Topics Page: www.osha.gov/SLTC/grainhandling/index.html.

• For additional information on safe workpractices in confined spaces, see 29 CFR1910.146, Permit-Required ConfinedSpaces.

• For additional information on respirators,see 29 CFR 1910.134, Respiratory Protection.

• For additional information on preparingyoung workers to work safely, please visit:• www.osha.gov/SLTC/teenworkers/index.

html, and• www.osha.gov/SLTC/youth/agriculture/

index.html

U.S. Department of Laborwww.osha.gov(800) 321-OSHA

For more complete information:

DEP 8/2010