Eli5: Why is flour, the most potentially disastrous food substance outside of liquid. Typically kept in paper bags, the worst at disaster prevention.

Question

Edit: sorry I was a little sarcastic and misunderstood. I didn’t mean literally disastrous (like explosive as some have you mentioned). I meant just really annoying when spilled.

In: Other

Answer 1

Flour burns aggressively when it’s dispersed, because of its very large surface area (due to very fine milling). When it’s packed into bricks, the available surface area is a lot lower because the particles are packed together tightly and there isn’t a lot of air (i.e. oxygen) between them. So if you hold a lighter up to a paper-bagged brick of flour it may catch on fire but it won’t be an instant explosion like what you’d get at a flour mill where there is flour in the air and spread out all over the place