Fall Protection for Grain Bins
From 2013 to 2014, grain bin entrapments notably increased, signaling that they are on the rise. In fact, grain worker entrapments increased by 15 percent in 2014, totaling 38 entrapments compared to 33 recorded in 2013 (“Grain entrapments” 30). According to Bill Field, a professor at Purdue University, young or inexperienced workers have an increased risk of injury due to grain entrapment or engulfment because working with grain is dangerous and requires special training. Field also explains that farmers over the age of 55 have an increased risk of injury because they can become complacent about the dangers involved after working so many years on the job (Field 2011).
What makes grain work such a dangerous field? There are two common ways grain workers become entrapped or engulfed:
- Grain unloading equipment is activated while a worker is on top of the grain inside the bin.
- After the grain in emptied from the bin, workers enter the bin at ground level to dislodge trapped grain above them.
A worker may find himself or herself in the first scenario above if the grain unloading equipment malfunctions. That worker then enters the grain bin without properly locking out the unloading equipment to see if he or she can fix the clogged equipment. Without knowing the first worker entered the grain bin, a second worker might start the unloading equipment. Assuming the unloading equipment is working at a low rate of 2,000 bushels per hour, that gives the worker inside the grain bin two to three seconds to react, four to five seconds until entrapment, and 11 to 22 seconds until engulfment (Nix 5).
A worker can also find himself or herself in the second scenario listed above. After the grain bin has been unloaded, grain is left clumped together and stuck to the sides of the bin. The worker then attempts to free the clumped grain. What the worker doesn’t know is that depending on the size of the grain bin, those clumps can be thousands of pounds. These large clumps can engulf workers—leading to severe injury or death.
Here are several tips to avoid grain bin entrapment or engulfment:
- Stay out of the bin unless there is no other option.
- Never enter the bin alone or without telling someone you are entering the bin.
- Lockout unloading equipment.
- Ensure workers are secured to the appropriate fall protection system.
Properly securing a lifeline is tricky because it requires an anchorage point. Typical farm grain storage bins do not provide adequate anchorage points because they are designed to store grain, not endure the forces of a fall event. In fact, roof components or bin ladders are not designed to provide sufficient anchor points and could fail if overloaded. There have been documented cases in which the victim tied himself or herself off to an internal or external bin ladder as an anchor point. The forces of the grain flow were so great that the ladder mounting bolts failed and pulled the ladder into the grain along with the victim (Field et. al. 2014 “Against”).
Not only do most grain bins lack adequate anchorage points, but the overwhelming majority of farm grain storage structures were designed and fabricated prior or without consideration to OSHA standards. The cost of meeting the current standards that apply to commercial (non-exempt) facilities would be significant or prohibitive under the current grain marketing system (see Figure 6.1) that farmers are required to use. Many older structures would have to be removed from service (Field et. al. 2014 “Basic”). Because farming is often multi-generational, farmers have been working in these old bins for years, so convincing them to make their bins OSHA compliant or to invest in a new OSHA compliant bin is difficult.
Before any changes are made to a grain bin, an engineer must determine its structural integrity and whether or not the structure can withstand fall event forces. After the grain bin has been approved, a fall protection expert should be called in to determine possible fall protection solutions. Remember that a self-retracting lanyard (SRL) should never be used as a “sole” fall protection device in grain bin applications because it’s possible for a worker to sink into the grain at a rate slower than the SRL engages. Fixed length lifelines should be used instead.
Purdue University and OSHA have great resources for grain bin safety. Although grain bin entrapment and engulfment seems to be steadily increasing, with proper training and equipment, workers can end this trend.
“Grain entrapments on the rise: report.” Safety + Health, July 2015. 30.
Field, Bill. 2011. “Grain Bin Safety” (video). National Corn Growers Association and the National Grain and Feed Foundation. http://extension.entm.purdue.edu/grainsafety/videos.php.
———, Charlene Cheng, Salah Issa, Brian French, Brandi Miller, Lamar Grafft, Matt Roberts, Don Haberlin, and Mike Manning. 2014. “Against the Grain.” Purdue University, Agricultural Safety and Health Program, and Department of Agricultural and Biological Engineering. 34. http://extension.entm.purdue.edu/grainsafety/pdf/classInfo/Safe%20Grain%20Instructor%20Manual/Instructors%20Guide.pdf
———, Steve Wettschurack, Steve Riedel, Matt Roberts, Gail Deboy, Pam O’Conner, Don Haberlin, Salah Issa, Lamar Grafft, and Charlene Cheng. 2014. “Basic First Responder Training Curriculum for Incidents Involving Grain Storage, Processing, and Handling Facilities.” Purdue University, Agricultural Safety and Health Program, and Department of Agricultural and Biological Engineering. 54. http://extension.entm.purdue.edu/grainsafety/pdf/classInfo/Instructor%20Manual/Instructor%20Guide.pdf
Nix, Damon C. [2011?] “Safe Grain Bin Entry” (PowerPoint). Georgia Tech Research Institute. http://oshainfo.gatech.edu/grain/module2-slides.ppt.
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