Any time there's an oxidizable powder that can get into the air, people get very nervous that it can cause a fuel air explosion. While technically true, the most flammable air-suspended powders you're likely to find are powdered sugar and flour, and somehow kitchens remain generally unexploded.

While plastic and metal powders are unplesant in the lungs, they aren't light enough to get into the air in the first place unless you have a kid throwing it around like confetti...