Post written by: Jay Myer, CPCU, CIC, ARM, CRM, AFIS
The ingredients for grain dust explosion are common in a farm environment: fuel (the dust), oxygen — which suspends the dust in the air — and an ignition source. All three ingredients can be found in grain elevators or feed mills. But the ignition source of most explosive fires is material handling equipment, such as legs and conveyors.
How explosions happen
Grain dust — from corn, wheat, wheat flour, wheat bran, soybeans, rice flour, rice bran, rice hulls, barley or oats — is the particulate fuel that makes a combustible dust explosion possible. Dust must hang in the air to fuel a fire, so heavier particles that fall to the ground are not a threat.
Like dust, ignition sources are plentiful on most farms, ranging from a lit cigarette to a welding or cutting torch to bearing or electrical failures. In dry conditions even seemingly benign events, such as a boot scuffing the ground, a lightning bolt or a truck backfiring, can spark a fire, making it even more critical to be aware of potential sources of combustible dust.
Minimizing the risk
Following a few common-sense rules can help you protect farmworkers, equipment and your property from the threat of combustible dust and reduce the risk of an explosion.
- Don’t smoke around equipment in operation. Ever. Post signs to that effect and let people know you strictly enforce “no smoking” regulations.
- Invest in grain dust explosion (GDE) prevention equipment. This includes explosion vents and motion sensors on legs, hot bearing detectors, inspection doors, plastic buckets (rather than metal) and magnets at conveyor receiving points, to pull out tramp metal debris that could spark fires. Also, consider the use of dust collection systems, sometimes called cyclone systems.
- Seal off dusty areas and equipment. Keep your electrical room sealed tightly behind a door and keep the space free of debris. Likewise, seal legs, conveyors and other handling equipment to prevent or reduce dust leakage.
- Choose dust-approved equipment. Only use trouble lights, heaters, extension cords and other electrical equipment that are designed to handle dust.
- Apply mineral oil to keep dust from suspending in the air. Most grain elevators already do this to protect their workers.
Finally, educate your employees and family members about the risks of combustible dust and the practices they can use to stay safe. For more information about insuring your farm against the risks of combustible dust, contact a local independent insurance agent. A list of agents in your area can be found here.