Officials requested a voluntary evacuation by residents within a one-mile radius of the Sanderson Farms feed mill and hatchery in Adel, Georgia, Saturday morning when a smoldering fire broke out in one of the plant’s silos.
Grain dust can be highly explosive. In 1977, two grain elevator explosions only five days apart in Texas and Louisiana killed 56 people. More recently, a 1997 grain dust explosion in Blaye, France, killed 11.
“By Sanderson Farms policy, all personnel were evacuated from the facility,” the Adel Fire Department Facebook page states. “A specialized team contracted by Sanderson Farms is in route to the facility to mitigate the situation.”
The voluntary evacuation request would stay in place more than seven hours until it was determined that the immediate danger had been removed.
Several factors must come together for a dust explosion. The critical parameter for grain particle size is 0.1 mm or smaller. As the size of the particle decreases, the risk of a deflagration or explosion increases.
Dust concentration contributes to flammability. The concentration must be between 40 grams per cubic meter and 4,000 grams per cubic meter, depending on particle size and composition. Also, the dust must be in suspension in order for an explosion to take place.
Further complicating the issue, the exact location of smoldering fires buried deep inside a grain filled silo can be difficult to detect even using thermal imaging equipment.