Ah, springtime, glorious springtime. You made it through the winter, you’ve shed those heavy, cold weather clothes and now you have boundless energy for spring cleaning. When it comes to spring cleaning, most people think of traditional house cleaning and organizing, but what about spring cleaning for your beauty products?

Clearing out your makeup drawer and/or makeup case once a year makes room for new products and updated colors. This is especially true if you’re like most women and you accumulate cosmetics by the bagful over the course of a year. You’ll likely find products at the bottom of your makeup case or drawer that you forgot about – like that fabulous scarlet lipstick you bought but never wore.

As you clean out your makeup, take time to wash your brushes thoroughly. Natural oils and embedded makeup accumulate deep in the bristles over time, which invites bacteria. Dawn dish washing liquid is a quick way to thoroughly remove oil from brushes. It’s even used to clean birds and other wildlife that have been exposed to oil spills. If it can clean the birds, it can certainly remove oil from your brushes.

If you’re a little reluctant to get rid of half-full bottles of mascara or an almost-full eye shadow container, you’re not alone. We spend a lot of money on those products! After all, the revenue of the U.S. cosmetic industry amounted to about 62.46 billion U.S. dollars in 2016, according to Statista.com. That’s a lot of green to be throwing away.

But experts say outdated makeup could make you sick. Do you know what’s crawling in your makeup?

“Most women do have a drawer full of cosmetics that have been partially used,” says Angela Bowers, M.D. of Southlake Dermatology in Texas.

Unfortunately, even makeup that appears “functional” could be harming you. Eye products like mascara and eye liner are some of the worst offenders.

“Bacteria can get in there and the preservatives might not be working quite as well as they were when you first opened it. If you get some of that in your eye you may develop conjunctivitis which we know as pink eye,” explains Dr. Bowers.

Outdated cosmetics also could cause breakouts or lead to even more serious skin problems. Sharing certain cosmetics, such as lipstick, could even spread viruses that may lead to viral meningitis.

Most cosmetics don’t list expiration dates, so it’s hard to know when to discard them, especially if they still look okay (or are just barely used).

Experts suggest you keep track of the day you open your makeup.

The following are some expiration dates for you to go by, courtesy of Marie Claire magazine and Dr. David Schlessinger, a board-certified oculoplastic surgeon and ophthalmologist, and medical director of Schlessinger Eye & Face:

Powders and shadows: 2 years
Cream shadows: 12 to 18 months
Foundation: 1 year
Lipstick & lip liner: 1 year
Mascara & eyeliners: 3 months
Makeup brushes: Clean weekly using a mild detergent, such as Dawn dish washing detergent for getting the oils out.
Makeup sponges: Replace weekly, or when the sponge becomes soiled.