1. You let hair collect in your hairbrush.Verdict: Gross, but harmless It’s normal to lose up to 150 hairs a day, and many of those strands pile up in your brush, along with residue from styling products, natural scalp oils, and dead skin. While a fuzzy brush isn’t necessarily a threat to your health, it will affect the way your hair looks. “That buildup can make your freshly-washed hair greasy,” says Francesca Fusco, MD, assistant clinical professor of dermatology at Mount Sinai Hospital in New York City. The fix: Use a comb or your fingers to remove the fallen strands from your brush’s bristles daily, and wash the brush (whether it’s natural or plastic) in a mixture of water and shampoo at least once a month, says Fusco.  MORE: 6 Gross Ingredients Lurking In Your Beauty Products
  2. You keep cotton pads and swabs on your countertop.Verdict: Gross, but harmless When you flush your toilet, little bits of bacteria spray into the air and land on exposed surfaces in the bathroom, so you don’t want cotton swabs—or anything else you’ll be putting directly on your face—sitting on the countertop, says Keri Peterson, MD, an internal medicine specialist in New York City. While it’s unlikely you’ll catch an infection this way (it would be more of a risk if you were to, say, stick that cotton swab up your nose or in your mouth), it is pretty unsanitary.  The fix: Close the lid when you flush your toilet to contain the spray, and move cotton swabs to a drawer, cabinet, or a closed container on your countertop. 
  3. You keep your facial brush in the shower.Verdict: Gross, but harmless All the steam and humidity in your shower makes it tough for your sonic facial brush to dry out between uses, and wet bristles are a breeding ground for mold and bacteria, says Ranella Hirsch, MD, a Boston-based dermatologist. Though infection is unlikely (unless your skin’s barrier is broken due to a popped zit or scratch), washing your face with a moldy brush is pretty darn icky.The fix: After every use, wash bristles with anti-bacterial soap and warm water. Then let the brush dry and store it in a well-ventilated spot, like your nightstand drawer (your bathroom cabinet gets hits of humidity every time you shower). To further protect the bristles against bacteria, consider a skin brush with anti-microbial silver threads woven into its bristles; while you’ll still need to clean it, it’ll slow bacteria growth. Try Clinique’s Sonic System Purifying Cleansing Brush ($89.50, clinique.com). 
  4. You dip your fingers into your face cream.Verdict: Flirting with infection If you dip anything but just-washed fingers into the container, you’re introducing dirt, oil, and germs to your cream—and thereby your face. But even if you cleanse your hands and face right before slathering it on, double dipping is a threat to your skin’s health, Hirsch says. If you rub the cream over any open acne spots or cold sores and then stick your fingers back the jar, it’ll be contaminated with bacteria. While it’s unlikely the acne bacteria would cause another breakout, there is a chance to you could be in for another cold sore, she says.  The fix: Always wash your hands before applying any product on your skin, and use a plastic spatula (many creams come with one) or cotton swab to scoop a dime-size dollop into the palm of your hand.
  5. You don’t wash your makeup brushes.Verdict: Flirting with infection If you rarely cleanse your cosmetic brushes (one British study found that 72% of women never do), you’re putting on more than makeup when you swipe them across your skin. “Brushes pick up dirt, oil, and grime, and you’re putting that on your face,” says Peterson. At the very least, this bad habit can clog pores and cause breakouts; at worst, dirty eyeliner and shadow brushes can lead to nasty infections like pink eye. The fix: At least once a week, spritz your brushes with an anti-bacterial brush spray after use—prioritize eye and lip products, since these can transmit the most germs, says Fusco. Try Japonesque Makeup Brush Cleanser ($14, ulta.com). Once a month, give brushes a deep clean with a gentle, sulfate-free shampoo and water. Place them flat to air dry (this helps the brush maintain its shape). MORE: 10 Beauty Products You Should Never Use After 40
  6. You use a loofah in the shower.Verdict: Full-on health hazard If it’s hanging out in the humid shower, your scrubber is a breeding ground for mold, fungus, and bacteria, including serious ones like staphylococcal (staph). “Staph lives on the skin naturally, but becomes a problem if it gets into the skin,” says Peterson. “If you have any open cuts or you scratch your skin with the loofah, the bacteria can get in and cause an infection.” Even if you let it dry between uses, research shows that loofahs can harbor a type of bacteria that causes a skin rash known as folliculitis, which results in red, itchy bumps around the hair follicles. The fix: Lose the loofah. Instead, slough off dead skin cells by hand using an exfoliating body wash, says Peterson. Try Softsoap Fresh & Glow Exfoliating Fruit Polish Body Wash ($4; walgreens.com), which is made with biodegradable ground apricot seeds, not the typical environmentally hazardous plastic microbeads. 
  7. You share a razor.Verdict: Full-on health hazard Borrowing your husband’s razor is no big deal, right? Wrong. “Sharp objects that can cut the skin pose the biggest health risks,” says Peterson. Razors can transmit viruses like hepatitis B and C and herpes (which can live on the skin, even if you don’t have a current outbreak) bacterial infections such as folliculitis, and staph infections like MRSA, a tough-to-treat bug that can be life-threatening. Even your own razor can become problematic if you hang onto it too long, since bacteria and mold can grow on it. “And if you nick your skin, which is more likely to happen with an old, dull blade, you can get an infection,” Peterson says.  The fix: Get your own—and care for it properly. Rinse your razor after each use and let it dry in a spot outside of your shower. “Keep it upright in a glass or use a suction cup holder so the water drips down,” says Fusco. (Once the razor dries, cover the blade to protect it from spray from your toilet.) If you shave daily, change the blade at least every two weeks so it’s sharp and less likely to nick you. 
  8. You “try before you buy” at the cosmetic counter. Verdict: Full-on health hazard Using the disposable applicator provided isn’t enough to keep mystery microbes off your lips and lids. You can’t be sure that everyone is following the rules and not touching the product directly or double dipping, says Fusco. “Even if you apply a tester lipstick with a cotton swab, you can still be exposed to viruses—anything from the common cold to herpes.” No exaggeration: research done at Rowan University in New Jersey revealed that makeup “testers” commonly contain staph, strep, and even E. coli. The fix: Skip the testers and ask for free samples, says Fusco. “Many cosmetic companies stock mini-sized products for sampling,” she says. If you must test, ask the salesperson to wipe the surface of the product with alcohol first and scrape off or sharpen the top layer. Then try it on your neck or inner wrist instead of putting it on your face (test foundations on your décolletage, which has similar coloring), and wash up immediately after. MORE: 10 Slimming Style Tricks That Take Off Years
  9. You pluck your nose hairs.Verdict: Full-on health hazard As easy a fix as it may seem, yanking nose hairs out with tweezers is a bad idea. If your tweezers aren’t clean, you’re putting germs in direct contact with a mucous membrane, which gives the bugs a fast-pass to your bloodstream, says Peterson. The other issue is that nose hairs are meant to trap germs. “By removing those hairs, you’re leaving yourself more vulnerable to illnesses like the common cold.” The fix: Trim, don’t pluck. Sanitize the clippers beforehand with rubbing alcohol and trim just enough so the hairs are no longer visible outside your nostrils. To play it safer, use a motorized nostril trimmer so you’re less likely to nick yourself, says Peterson. One to try: Panisonic Vortex Nose & Facial Hair Trimmer ($15, walgreens.com).