Elizabeth Brooks, a professor at Jefferson Medical College in Philadelphia, has some advice for people trying out makeup when they’re out shopping. As most people know, makeup can harbor bacteria and viruses, and shared testers are the worst offenders: Brooks tested hundreds of makeup counter samples for a study and found 100% of it was contaminated with things like staph, strep, and E. coli.

Here’s what she told the Los Angeles Times:

• Avoid trying jar lotions and only test ones you can squeeze or pump out.
• Clean the surface of the tester with a tissue or a tissue dipped in alcohol before trying it.
• Don’t use communal makeup brushes; the ones made from animal hair are especially hard to keep clean.
• Ask for disposable brushes or pads to apply makeup. Brooks says every counter they tested had these things behind the counter, but not on public display.
• If you insist on trying out lipstick, first debride it with a disposable applicator.
• Avoid any makeup testers that come in contact with the eyes, nose or mouth.

“Handle those store makeup testers with care” [Los Angeles Times]

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