Would you consider eating a slice of moldy bread? Chances are there may be just as many gross microbes present in your favorite beauty products that you diligently put on your skin every day—and the tools you use to apply them.
According to a 2019 study published in the Journal of Applied Microbiology, 70-90% of all products tested, including lipsticks and makeup sponges, were contaminated with fungus and bacteria.
"Mold can grow on skincare and makeup items for a variety of reasons. When the product is past its expiration date, when they aren't stored properly and when the applicators are not cleaned regularly and thoroughly, to name a few," says Michael Rubino, air quality expert and author of The Mold Medic.