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Grain entrapment, or grain engulfment, occurs when a person becomes submerged in grain and cannot get out without assistance. This more frequently occurs at storage facilities such as silos or grain elevators, but has been known to occur around any large quantity of grain, even freestanding piles outdoors. Usually, unstable grain collapses suddenly, wholly or partially burying workers who may be within it. Entrapment occurs when victims are partially submerged but cannot remove themselves; engulfment occurs when they are completely buried within the grain. Engulfment has a very high fatality rate.
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While the death rate from workplace accidents on American farms has declined in the first decade of the 21st century, grain-entrapment deaths have not, reaching an all-time annual high of 26 in 2010. Many of those victims have been minors. Agricultural organizations have worked to protect them and improve rescue techniques, as well as spread awareness among farmers of prevention methods. Primary among these is a federal regulation that forbids opening an auger or other opening at the bottom of a grain storage facility while someone is known to be "walking down the grain" within.
Smaller family farms, however, are exempt from most federal labor regulation specific to agriculture, and no safety regulations govern children working for their parents. In 2011 the US Department of Labor proposed sweeping new regulations that would have changed this, prohibiting underage workers from being allowed to enter silos, among other provisions. They were withdrawn after protests from farmers and politicians of both US parties.
Occurrence
At some grain-handling facilities, employees "walk down the grain" on top of it to expedite the flow of grain from the top when it is being allowed to flow out the bottom. This is the most common cause of grain entrapments. Regulations issued by the Occupational Safety and Health Administration (OSHA) specifically forbid this at larger commercial facilities subject to them; most smaller farms are not. It may also be necessary to enter a grain storage facility to remove damp, clumped grain (usually from early spoilage) stuck on the walls. Entrapments have also occurred to children in grain transportation vehicles, or to those outside when grain is released from a storage facility or next to large freestanding grain piles.
Workers in the grain can become entrapped in three different ways. An apparently stable surface may in fact be a "grain bridge" over an area underneath where the grain has already settled. A vertical mass of grain settled against a wall may suddenly give way while being cleared. Moving grain will not support the weight of an average person.
Once entrapment begins, it happens very quickly due to the suction-like action of the grain. A human body in grain takes seconds to sink, minutes to suffocate, and hours to locate and recover. Recovered bodies have shown signs of blunt force trauma from the impact of the grain; one victim was found to have a dislocated jaw.
However, suffocation does not occur from the weight of the grain, rather from the grain itself. If a victim's airway remains unobstructed, or they find an air pocket within the grain, they may be able to keep breathing and be rescued. In one instance a trapped person was able to survive for three hours.
Rescue
Several factors complicate the rescue of entrapment victims even if their heads remain above the grain. Most grain storage and handling facilities are located on farms in rural areas, often distant from trained rescuers such as fire or ambulance services. They are also confined spaces, posing hazards to rescuers.
Foremost among them is the air within. Toxic gases, such as carbon dioxide or nitrogen oxides, accumulate from spoiling grain. They can cause asphyxiation in great enough concentrations without proper ventilation of the area. The dust can also sometimes have molds or spores that may be toxic or cause allergic reactions. There is at least one documented instance of a first responder requiring treatment as a result of such inhalation; rescuers are advised to wear at least dust masks or even self-contained breathing apparatus (SCBA).
As soon as an entrapment occurs, in addition to immediately notifying local emergency services, the workers at the facility should shut off anything causing motion in the grain, or close any outlet. The aeration fan should be turned on to improve ventilation, but without any heat source activated. Rescuers must always take care not to make the situation worse, or take action that would result in they themselves becoming entrapped or engulfed. They should wear proper safety equipment such as lifelines. No more than two should walk on the surface of the grain at any time.
Temperature extremes can cause problems for both rescuers and victims. Stored grain is often kept fresh by blowing dry air over it. This, combined with any moisture in the grain, can chill its core to 30-40 °F (-1–5 °C), creating a risk of hypothermia for the victim, especially one fully engulfed. Conversely, the air within the bin may be warmer than usual due to the heat released by decaying grain, the lack of exterior ventilation (especially on hot days) and any rescue activity; there is thus a risk of heat illness for those trying to free the victim.
Even if a living victim is roped, they cannot simply be removed that way. Grain creates friction that resists the force used to pull them out. It requires 400 pounds (180 kg) of force to lift a victim buried up to their waist; removing a human completely trapped in grain takes 900 pounds (410 kg). Both of these amounts are above the level that can cause permanent spinal column injury.
Rescues of an entrapped victim usually entail building makeshift retaining walls in the grain around them with plywood, sheet metal, tarpaulins, snow fences or any other similar material available. Once that has been done, the next step is creating the equivalent of a cofferdam within the grain from which grain can then be removed by hand, shovel, grain vacuum or other extraction equipment. While some of these techniques have been used to retrieve engulfed victims or their bodies as well, in those cases it is also common to attempt to cut a hole in the side of the storage facility; this requires consulting an engineer to make sure it can be done without compromising the facility's structural integrity. There is also the possibility of a dust explosion, although none are known to have occurred yet during a rescue attempt.
Prevention
The best way to prevent grain entrapments is to store grain properly. If kept at the proper moisture level of 14% or less and protected from the elements, grain will not form the kind of clumps that create grain bridges or other areas of unequal density within. Entrapments are more likely when grain is more spoiled. "Coring" grain by removing some of it from the center after the facility has been filled also reduces spoilage since it generally takes the broken and smaller grains where insects tend to start growing within.
Strict policies about entering the area where grain is stored further prevent entrapments. Workers should never be alone, but if they must be they should have a radio or cell phone to communicate. Signs indicating the potential hazard should be posted at the entry, and anyone who does not have a good reason to be in the grain should never be there.
OSHA's regulations require that employees who enter stored grain do so attached to either a lifeline or boatswain's chair, that one other employee be assigned to observe them, and that rescue equipment adequate to the task be available. At farms and feedlots not subject to those regulations, it is sometimes common to tie a permanent lifeline to the inside of the storage facility. This has not been found to be effective, as the grain's suction often pulls the victim under the surface too fast for them to reach it, and most are not secured firmly enough that they would not fail under the load.
Statistical trends
Since 1978, the Agricultural Health and Safety Program at Purdue University in Indiana has documented grain-entrapment incidents. Its National Agricultural Confined Space Incident Database has, as of 2011, records on 900 reported entrapments dating to 1964. The program has analyzed them to find consistent patterns in the hope of improving prevention and rescue efforts. Among the statistically significant patterns it has found are the type of grain in which incidents predominantly occur, the geographic locations of incidents, the type of facility they occur in and the demographics of victims.
More than half the recorded entrapments and engulfments have occurred in corn. Other grains in which victims have become entrapped include soybeans, oats, wheat, flax and canola. Given the predominance of corn as an entrapment medium, most incidents occur in the Corn Belt states (Illinois, Indiana, Iowa, Minnesota and Ohio) where that grain is grown and stored in quantity. Farms in states in the Upper Midwest and West, where humidity is lower and smaller grains are preferred, report fewer incidents. Over 70% of entrapments have occurred on small or family farms of the type exempt from OSHA grain-handling regulations.
Victims have been exclusively male. Three-quarters of them have been farmers, farm workers, or members of farm families. The average age of victims is in the 40s, but a disproportionate share are under 18 (youths 16 or older can work in agriculture without any restrictions).
In 2010, the researchers noted that 38 incidents had occurred during 2009, when the national corn harvest set a new record. This was not only the highest since 1993, it capped a period in which the five-year average had steadily increased. This rose to a record-setting 51 in 2010, when a similarly large corn harvest had a high moisture content and low test weight. Observers speculate that the demand for ethanol fuel production has fostered the increase of corn in storage. The record entrapments ran counter to the trend of declining accidents in agriculture.
At the same time, more victims are being successfully rescued. Before 2005, a quarter of the victims were saved. Since then, the rate has improved to half. In 2011, when entrapments declined to 27, only 8 resulted in fatalities.
2011 proposed regulations
After a 2010 entrapment at a commercial grain elevator complex in Illinois killed two workers aged 14 and 19, while a third survived with injuries, OSHA assessed fines of over half a million dollars against the operators (eventually collecting little over a quarter-million). It sent letters to other grain-handling facilities afterwards reminding them of their legal and moral obligations to prevent such deaths. A year later, after another incident in Oklahoma where two teenaged boys lost legs to a sweep auger, the agency proposed new rules on child labor in agriculture.
They were the most extensive changes proposed in that area in a half century. Most minors working in agriculture work for farms with fewer than ten employees, which are exempt from most federal workplace-safety laws and regulations. Children who work on their parents farm are completely outside the scope of those laws, since it is believed that their parents would not let them do hazardous work. The proposed regulations, which took up 49 pages in the Federal Register, would have changed that. In its preface to the proposed regulations, the department noted that while agriculture employs only 4% of the country's underage workers, those workers account for 40% of overall deaths on the job.
However, the regulations drew opposition. While they preserved the exemption for small family farms, many observers, even proponents, felt they had overreached in scope and would prevent children of farm families from learning important skills at an early age. Even some of the family members of teenage boys who had died in entrapments told the media that the proposed rules went too far. Opposition mounted in Congress, where it was claimed that the proposed regulations were so broad they could have prevented children from doing chores on their parents' farms. Several Democratic senators from rural states facing hotly contested elections, such as Jon Tester, Claire McCaskill and Debbie Stabenow, complained about them personally to President Barack Obama.
In 2012, the Labor Department withdrew them, taking the unusual step of indicating, as it did so, that "this regulation will not be pursued for the duration of the Obama administration." Instead, the department said it would continue to work with youth-oriented agricultural organizations like the 4-H and FFA to increase awareness of safe work practices on farms. It has also begun levying more and heavier fines for safety violations.