Is it bad to share makeup?

Using makeup in a hygienic way can help you avoid picking up an unpleasant disease. Many women get so involved in their routines that they may not even realize that what they're doing each morning is, in fact, putting them at risk of infection.

First, examine how you store your cosmetics. Make sure that you close your makeup containers tightly after using them each day. This helps keep the product in good, safe condition for a longer period of time. Cosmetics normally contain preservatives that help prevent bacteria growth, but storing products incorrectly can mean germs will be able to grow. An important aspect of this is keeping products at room temperature; storing them in a hot place or in direct sunlight will make it much easier for bacteria to thrive. Anything above 85 degrees Fahrenheit (29 degrees Celsius) becomes dangerous for makeup storage [source: FDA].

You should never add water to makeup, either, as this can spur germ growth in a previously clean environment and lessen the effects of any preservatives added to the makeup that keep it more sanitary. And using saliva is an even bigger makeup don't: It can spread bacteria from your mouth, where they are harmless, to your eyes, which are much more sensitive [sources: Connolly and FDA].

Now you know not to share makeup with friends -- but what about with strangers? Sounds obvious, right? Well, what do you think you're doing when you try the latest lipstick shade at your local department store's makeup counter? If you must use a tester or plan to have a makeover done by a department store makeup consultant, insist on disposable applicators, learn about cleaning procedures (make sure they follow them) and request a new tester product, if necessary [source: Wu].

Wondering what could be lurking on that lipstick tester? Read on to learn about the different infections that can be spread via makeup.

Although a group makeover can seem like fun at the time, an outbreak of pink eye or another infection is not. Diseases aren't just spread through close friends; you can also pick them up if you use the tester products at the local beauty counter, or if you have a department store makeup consultant give you a makeover. In fact, one study found staph, strep and E. coli bacteria in department store makeup tester products [source: Wu]. Without safety precautions, a carefree makeover day can turn into a visit to the doctor.

One potential, and particularly pesky, result of sharing eye makeup is getting pink eye, also known as conjunctivitis. This infection of the lining of the eyelid results in red, itchy, watery eyes and can last for up to two weeks [source: Mayo Clinic]. Pink eye is very contagious, so it is easy to spread among people sharing the same makeup. If you come down with this disease, a doctor can prescribe medicated eye drops to clear it up within a few weeks, but you won't be able to wear eye makeup or contact lenses in the meantime.

Swapping lipstick with a friend who is infected with the herpes simplex virus, which causes cold sores, can pass the virus on to you. You can contract herpes even without visible cold sores present on the infected person -- and remember, there's no cure for the herpes viruses. Just one incidence of sharing your lipstick can lead to a lifetime of contending with the condition if you contract the virus.

In addition to keeping your cosmetics to yourself, ensuring that what you own is still in working order can also prevent disease. Keep reading to learn how to avoid makeup contamination.

Open up that bathroom drawer, and you may discover makeup that is well beyond its normal usage date. However, the U.S. Food and Drug Administration, which oversees cosmetics, does not require that manufacturers set an expiration date for such products. On top of that, some types of makeup can expire faster than normal if they are stored incorrectly. That means that it's up to you to decide when it's time to toss your beauty products.

Since eyes are one of the areas of the body that are most susceptible to disease, you should be especially careful when keeping track of how long you've had your current mascara. The closed container creates a dark environment that allows germs to thrive. Most manufacturers suggest tossing mascara just after the three-month mark. Of course, if it smells odd, has become dried out or has been exposed to drastic temperature changes, you might want to chuck it sooner than that. And if you've had a recent eye infection, no matter how long (or little) you've had it -- you should replace all of your eye makeup [source: FDA].

Other liquid products, or those that contain a large amount of water, also are breeding grounds for bacteria and should be replaced on a regular basis. After six months, get rid of liquid foundation, creamy-formula eye shadow and blush. And, like mascara, after three months, discard liquid eyeliner [source: Matlin].

Powder-based products, which contain little water, can last for up to two years. These include pencil eyeliner and lip liner, and powder eye shadow, foundation, blush and bronzer. But this doesn't mean that every type of makeup will necessarily last this long. If a cosmetic changes color or starts to smell, throw it out right away.

To learn more about the dangers of poor makeup hygiene, visit the links on the following page.