For flour to explode, it must form a highly dispersed dust. Approximately two ounces (56 grams) of flour suspended in a cubic yard (one cubic meter) of air will have explosive properties. If a flame is introduced to the flour dust, the individual flour particles will burn. If the dust cloud is large enough, a flash fire inside the dust cloud will result, which can create a serious explosion.

Flour explosions are a much larger risk in areas where large amounts of flour are handled. Although a small dust cloud of flour might ignite in a home kitchen, the damage would probably not be severe. In a grain elevator or flour mill, however, the potential for a very large cloud of flour or grain dust is much higher.… Read on...