Buried Alive – Grain Suffocation Hazards
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BURIED ALIVE GRAIN SUFFOCATION HAZARDS WSI North Dakota Workforce Safety & Insurance 1600 E Century Ave Ste 1 PO Box 5585 Bismarck ND 58506-5585 (701) 328-3800 1-800-777-5033 This publication is produced by the Loss Prevention Education Unit and the Communications Department of Workforce Safety & Insurance (WSI) with contributing writers noted. Photo credit: Lisa Gerving, Connie M. Johnson, Zach Knoop, and Comstock Images. June 2002; Edited and Reprinted June 2006 Disclaimer Although the information and recommendations contained in this publication have been compiled from sources believed to be reliable, WSI makes no guarantee as to, and assumes no responsibility for, the correctness, sufficiency, or completeness of such information or recommendations. Other or additional safety measures may be required under particular circumstances. Contents Suffocation Hazards in Grain Bins ...................................................... 3 Grain Bin Rescue Procedures ............................................................ 10 Don’t Go With the Flow .....................................................................11 Handle Your Grain Harvest With Care .............................................. 12 Lockout/Tagout: An Essential Safety Procedure ............................... 14 OSHA Regulations: Entry Into Grain Storage Structures .............................................. 16 Grain Handling Safety on the Web .................................................... 19 Video Resource Library ..................................................................... 20 Introduction Suffocation in flowing grain is the most common cause of death associated with grain storage structures in the United States. The Occupational Safety and Health Administration (OSHA) estimates that 15 to 20 employees each year are suffocated during storage bin and grain elevator accidents, and this, according to OSHA, is a very conservative estimate. Since 1995, three suffocation fatalities have been reported to WSI that were the result of engulfment in grain - with the most recent being in 2002. The information contained in this publication indicates that suffocations in grain bins are a continuing source of preventable occupationally-related deaths among workers in the agriculture industry. Occupational safety and health training remains a fundamental element of hazard control in the workplace, and there is great potential to reduce these incidents through pre-employment training. Effective pre-employment training should in- clude realistic environments and hands-on exercises. This publication is designed to engage the learner in recognizing, evalu- ating, and controlling engulfment hazards associated with grain storage facilities. 2 Loss Prevention Education Unit (701) 328-5913 or 1-800-777-5033 Suffocation Hazards In Grain Bins The number of suffocations in grain storage systems investment closely and frequently. You may enter has been increasing over the past several years. There a grain bin to visually check the grain’s condition appear to be at least five basic reasons: and may probe the bin to determine the grain’s temperature and moisture content to ensure that 1. The increase in harvesting and handling of grains, there are no “hot-spots” developing in the center of 2. Grain bins on the farm are getting bigger, the bin. 2. Grain being removed from a bin equipped with a 3. Grain handling rates are faster, bottom-unloading auger may fail to flow because 4. More operators are working alone due to increased of clogging or bridging. The operator may feel that mechanization, and the only option is to go inside the bin and remove 5. Some operators are not aware of how grain flows the obstruction or break up the bridged grain. from bins and, therefore, do not understand the 3. When drying grain, the successful operator will dangers involved. check the incoming grain closely. You may feel that the wet holding bin is the best place to make Don’t make the mistake of your life. Be aware of the observations. dangers of flowing grain. 4. Children may find that a storage bin filled with grain is an ideal place to play. There are several reasons why you might enter a bin filled with grain… … and there are several reasons why you may not 1. The successful manager of stored grain checks this come out alive. [email protected] 3 Why is flowing grain so dangerous? To better com- bin or a bottom-unloading auger is started, grain flows prehend the hazard, the way in which most farm from the top surface down a center core to the un- storage bins unload must be understood. Grain storage loading port or auger. This is called “enveloping flow” structures should be, and usually are, unloaded from and is illustrated in Figure 1. the center. When a valve is opened in the center of the Auger stopped Unloading begins Unloading continues Figure 1. When bins unload, the grain at the top of the bin is removed first. The grain across the bottom and around the sides of assuming an average body diameter of 15 inches. the bin does not move. The rate at which the grain This means that the entire body could be submerged is removed is what makes the enveloping flow so in the envelope of grain in approximately 22 seconds. dangerous. A typical rate for a bin unloading auger is Even more importantly, you could be up to your 1,000 bu/hr. This is equivalent to 1,250 cubic feet per knees in grain and totally helpless to free yourself in hour or approximately 21 cubic feet per minute. A less than 5 seconds (Figure 2). person 6’ tall displaces about 7.5 cubic feet, From the time the auger In 4-5 seconds, After 22 seconds, you starts, you have 2-3 you are trapped! are completely covered. seconds to react. Figure 2. Twenty-two seconds to suffocation. 4 Loss Prevention Education Unit (701) 328-5913 or 1-800-777-5033 You must remember that flowing grain is like water in merged children from grain have commented on how that it will exert pressure over the entire area of any hard they had to pull and, frequently, that shoes were object that is submerged in it. However, the amount pulled off in the grain. This may mean that rescue ef- of force required to pull someone up through grain forts will fail unless the movement of grain is stopped. is much greater than required in water because grain Grain that bridges across a bin can be another hazard. exerts no buoyant force and has much greater internal Bridging grain may create air spaces in a partially friction. People who have helped pull partially sub- unloaded bin (Figure 3). Before unloading, Air space is created Air space remains a condition that may as unloading begins. after unloading stops. cause bridging. Figure 3. Potential hazard created by bridging. Note also that when the air space becomes large enough, the bin walls may buckle. This situation presents several dangers. The first is trapped instantly in the flowing grain (Figure 4). that the person may break through the surface and be A dangerous situation As unloading begins, the Before the grain flow can created by a previous bridged grain falls into be stopped, the man is partial unloading of the air space and the covered. In a matter of the bin. man is instantly trapped. seconds - suffocation. Figure 4. Two basic principles were violated. First, the person entered a bin of grain that was out of condition without seriously considering its previous unloading history. Second, he didn’t ensure that unloading could NOT occur while he was inside. [email protected] 5 Another danger is that a large void may be created under the grain and suffocate even though the unloading under the bridged grain by previous unloading so that auger may not be in operation at the time (Figure 5). a person who breaks through the crust may be buried Probing bridged grain It may very well result ...with suffocation presents a dangerous in a breakthrough to occurring in a situation... disaster... matter of seconds. Figure 5. Bridged grain presents a danger, even when the bin is not being unloaded. A third hazard is that, if the grain is wet enough to limited to those with bottom unloading augers. Grav- mold and bridge across a bin, there may be little ity unloaded bins may present a similar danger through oxygen present in the cavity because of microbial bridging or unloading. A definite danger exists with action. Therefore, a person falling into this void may wet holding bins that feed automatic-batch grain dryers. be forced to breathe toxic gases and microbial spores When the dryer completes its drying cycle and reloads, even if the head stays above the level of the sur- a person in the wet holding bin can be drawn below the rounding grain. Safety hazards in grain bins are not surface of the grain in a matter of seconds (Figure 6). Inspecting grain in the wet hold- ...may result in death during the ing bin during the drying cycle... refilling cycle. Figure 6. In a modern grain facility, bins may load or unload automatically, thereby adding to the suffocation hazard. 6 Loss Prevention Education Unit (701) 328-5913 or 1-800-777-5033 Flowing grain hazards, in addition to mold and dust wall of grain may look perfectly safe, but one scoopful health hazards, exist when working with grain that has could pry out the “foundation” and start an avalanche gone out of condition or has built up in a tall pile. A or “cave-off” (Figure 7). Beware of a steep because it may and result in pile of grain... tumble down... suffocation. Figure 7. Beware of a tall pile of grain. A person lying prone and covered by 1 foot of grain will be subjected to a force of over 300 pounds. Grain is heavy. For example, a 6’ tall person, prone body harness connected to a mechanical lifting device and covered by 1 foot of corn, will be under about 300 (hoist, block and tackle, etc.) that is secured outside lbs.