I read on some government website that if there were a lot of sugar particles or flour particles in a space that with a source of ignition you could cause a small explosion.
You could actually cause a very large explosion with anythink like sugar or flour. I think any substance full of carbohydrates will explode if its ground fine enough and theres enough of it floating in the air.
There was a serious explosion at a flour factory possibly in america where several people lost their lives.