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



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

Because paper bags are cheap and because the rate of this causing serious problems is approximately zero.

For flour to be dangerous you have to set it on fire and burn a lot of it at once. That means spreading lots of it in the air. If you run a mill, this can be a problem and you should be very careful about sources of flame. If you store packed flour or bake a cake at home, the danger is negligible.

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

Paper bags are cheap. There’s no other reason really. It’s not liquid or chemically reactive so you don’t need plastic/glass/metal. Many people will dump the flour into a reusable plastic container once they get home anyways, so there’s no real benefit in bundling a more expensive package with the flour when it’s just gonna get thrown awyay.