ABC News' Elisabeth Leamy and Vanessa Weber report:
Women everywhere are drawn to the makeup counter by the allure, glamour and intrigue of achieving a new look.
But what else could you be putting on your face along with the sparkle of a new blush, the glitter of eyeliner and the glamour of a new lipstick when you sample products from a store's makeup counter?
If you're not careful, it could be everything from yeast to mold to dangerous bacteria strains that have accumulated on the samples over time. Those strains could lead to rashes, infections, break-outs and more on your skin.
An undercover test conducted by " Good Morning America" found that one out of every five, or 20 percent, of samples we tested from 10 stores across two states showed significant growth of mold, yeast or fecal matter.
"You don't have to panic," Dr. Philip Tierno, director of microbiology at New York University's Langone Medical Center, told "GMA." "You just have to realize that if you have an open cut, you might not want to go that route of using makeup that has been used by other people before you."
Linda Wells, Editor-in-Chief of Allure magazine and an expert in the field of make-up and beauty, agrees.
"To me, makeup testers are like petri dishes," she told "GMA." "I would not want to go near one or put anything in that tester on my face."
Luckily, Wells says there are ways to avoid exposing yourself to germs while still testing out new beauty looks.
Here are Wells' top safety tips to try the next time you're in the market for new makeup.
1) Research the makeup you want online before you go to the store, so your choices are narrowed and you don't have to try as many.
2) Be wary of even disposable wands because you never know how many people double-dip the samples.
3) Stay away from open jars of lip gloss, moisturizer and foundations, because people may have dipped their fingers into them -and hands are hotbeds of germs.
4) When testing eyeshadow and eyeliner, use a disposable applicator and test it on your hand, not your eyes.
5) To test a new foundation, apply it to your neck, away from your face and lips.
6) Ask the salesperson to sterilize lipstick tubes with alcohol before you try them. Our "GMA" tests showed that kills the bacteria.
7) To try a new lipstick shade, apply it to the pad of your finger, not anywhere near your mouth.
8) Test concealer on your inner wrist, not your face, where the lighter coloring will usually match your under-eye area.
9) Never test mascara from a used tester bottle. Ask the clerk to open a fresh tester and give you a disposable wand. Dip each wand only once, to avoid contaminating the sample for the next customer. If a new tester isn't an option, don't test at all. Instead, ask the salesperson to describe the mascara to you.
10) Many stores now have a "buy and try" policy, where you can purchase cosmetics, take them home to try on, and then get a full refund if you're not happy.