if you use mineral powder cosmetics, you probably use bismuth oxychloride, commonly called BOC, for its shimmer and pearlescent luster. Bismuth is the only heavy metal classified on the Material Safety Data Sheet, MSDS, as non-toxic in all of its commonly used forms, including BOC. Side effects are rare and usually mild, but certain cautions are still advised by the U.S. Centers for Disease Control, or CDC. Respiratory, skin and neurological side effects have been documented.
Inhaling BOC powder, perhaps while applying dry cosmetics, produces an irritant effect on your nose, throat and lungs, making you sneeze and cough, according to the CDC. The crystalline, particulate nature of the powder rather than a direct toxicity causes this irritation. BOC in your eyes will cause redness, watering and burning.