Grain-handling Presents a Variety of Safety Hazards
By Safety Management Group
When most people think about farming, they imagine a quiet, peaceful life in the country. Few realize agriculture has long been one of the most dangerous occupations, with high injury and death rates.
One of the most hazardous areas within agribusiness is the handling of grain. With the development of the ethanol industry, many new jobs have been created related to the storage and processing of tremendous volumes of corn and other grains. Most of these operations are in rural areas, where workers are more accustomed to the hazards of agricultural work, but those who haven’t grown up around farming may not be aware of the inherent potential for danger.
There’s a long list of hazards associated with grain handling, including suffocation caused by engulfment and entrapment; falls, fire and explosions; crushing and amputations; and breathing difficulties. We’ll examine each more closely and provide suggestions for safe work practices.
Engulfment and entrapment
Purdue University reported that 26 of the 51 grain-industry workers who became engulfed by grain in bins during 2010 died as a result of the incidents. Piles of grain may appear to be fairly solid, but the reality is that grain — especially when moves — exhibits properties that are very similar to quicksand. Movement or voids beneath the surface can create powerful suction that trigger surface collapses, drawing workers on the surface deep into the pile. The risk increases when the surface gain has developed a crust, or when spoiled grain has begun to form clumps.
Engulfment accidents typically occur when workers try to clear build-ups of grain within bins or on devices such as conveyors. Sometimes they occur when workers try to use the surface of the grain as a short path to another area. It’s important to prohibit workers from walking on grain piles for any reason.
Anytime workers have to enter a bin or silo for work reasons, they should use the proper personal protective equipment (PPE), including a body harness and a properly tied-off lifeline (or a similar device). Workers in those environments should always be observed by another employee who can monitor their safety and provide or obtain emergency assistance. All mechanical devices such as augers inside the bin or silo must be shut off and locked out.
Grain handling equipment is often among the highest structures in an area. Ladders, catwalks, roofs, manways, and other surfaces are typically far enough above the ground (and any equipment below) that a fall would lead to serious injury or death.
That’s why workers should wear proper fall protection devices such as lanyards. Proper engineering, such as safety cages around exposed ladders, will limit the potential hazards. Workers must also be conscious of safe practices such as not climbing ladders when they are wet or icy.
Fires and explosions
The dust created in storage and processing tends to be highly flammable and explosive. Grain elevator explosions are spectacular and surprisingly deadly. In the past 25 years, more than 180 workers have died in explosions in grain-handling facilities. There are many potential ignition sources in these facilities, including hot engine parts, electrical shorts, and maintenance activities such as welding.
Proper ventilation is the first step in preventing fires and explosions. An ongoing program to reduce dust creation and accumulation, and to identify and address potential ignition sources, is an important step. As little as one-eighth of an inch of accumulated grain dust on an exposed surface is enough to fuel a catastrophic fire. Dust collection systems must be cleaned and checked regularly, and filters must be in good operating condition. Bucket elevators and similar equipment should be designed and maintained to minimize the creation of static electricity, friction, and excessive heat. Also, the air inside bins and silos should be tested for combustible gas before any interior work begins. If gases are above safe levels, the area should be properly ventilated and tested again before work proceeds.
Crushing injuries and amputations
Workers who are in close proximity to mechanical equipment such as conveyors and augers face the risk of being entangled, leading to crushing injuries or the accidental amputation of limbs. The guards, covers, and shields that are designed to protect workers can only serve their function when used properly. Workers who defeat or disable such protection place themselves at significantly greater risk for injury.
Workers should also be protected by a lockout-tagout program to ensure that machinery is not energized when they are performing maintenance or clearing clogged equipment.
Grain storage and processing facilities can also contribute to the development of airborne contaminants. These range from gases produced by decaying grain to molds and toxic fumigants applied to control insects or other pests. A large enough amount may displace oxygen in the facility and cause a worker to become overcome and fall into the grain.
The natural process of decay can create poisonous gases such as hydrogen sulfide, nitrogen dioxide and tetroxide, and ammonia. Even common gases like methane and carbon dioxide can reduce oxygen to unsafe levels within enclosures. That makes testing and ventilation even more important. It’s also why workers should wear the correct type of respirator for the situation. They should never enter a confined space without being observed by at least two other workers who can initiate emergency assistance if needed.