Flour: found in bread, cookies, cakes, … and explosives?
Normally, the average flour you see in your kitchen isn’t that explosive. It would take a lot of matches to start a fire with flour, and even then, you might not get it to light. But flour’s flammability changes in an instant once it become airborne.
Flour is a starch, meaning that it is comprised of many long chains of highly flammable glucose. When packed tightly together, these glucose chains don’t have enough oxygen between each other to ignite. However, once there is air between the flour particles, one particles catches fire, which makes two others burn, which makes four others burn, and so on until all the flour particles have exponentially set each other on fire, making the fire very fast, very hot, and very explosive – even more explosive than coal dust. With flour suspended in air, the tiniest flame can light a whole room on fire, as has been proven in many tragic example, such as the one shown above.
(via Environmental Graffiti)