, also known as hydrous magnesium silicate, is a toxic ingredient similar to asbestos
. Listed on the Environment Canada Domestic Substance List
as a substance that is "expected to be toxic or harmful," talc is commonly found in eye shadow, baby powder, face powder, and other loose-mineral cosmetics, where it's used as an absorbent, anti-caking agent. Asbestos-containing talc particles have been known to cause tumors in human ovaries and lungs, according to the American Cancer Society
. Although asbestos-free talc has been widely used since the '70s, evidence about its safety remains fuzzy.