A new study revealed that "unclean makeup brushes, regardless of where they are stored, are much dirtier than one might think, and can contain a shocking amount of bacteria that may exceed that found on a toilet seat." The study was conducted on the cosmetic brand Spectrum Collections, where researchers swabbed clean and "dirty" makeup brushes at the end of a two-week testing period while examining several common storage methods including a makeup bag, brush bags, and drawers or brush holders in the bathroom.
When comparing the results to a toilet seat swab, the study found that "the bacteria count is either the same as or more than that found in the toilet regardless of where the brush is stored." Beauty expert Carly Musleh stated for Spectrum Collections: "Makeup brushes can transfer bacteria, dead skin cells, and oils from the face to the product, which could lead to fungal infections on the skin upon reuse." The sample results disclosed that "all unclean makeup brushes contained potential traces of E. coli, yeast, and mold, which can lead to fungal infections, while clean makeup brushes contained significantly fewer."
