Aha. No, I edited.

OK. Dat 'splain it.

fi wah

Salt, man, SALT!! By throwing flour on a fire you could actually cause a fireball/explosion. We had a flour warehouse explosion two miles from my house years and years ago. It rattled our windows, leveled the building, and burned for four days. The cause? Flour in the air inside the warehouse, and a single spark. No one hurt though.

Grease and flour...hmm, gravy?

That's too bad. Probably prior to the explosion flour was selling like...er, hotcakes.

Old apartment buildings in Boston, all had small door in the wall of the hallway, on each floor.
The doors were a hopper that tipped out like a mailbox so you could put your trash in the hopper and when you close the door the trash would drop down a common chute to the incinerator.
When a woman found worms in a 5 pound bag of flour, she dropped it down the chute. The bag hit each hopper on the way down filling the whole chute with flour dust by the time it reached the flames in the incinerator.
The building was condemned and torn down.