How many months or years you should hold on to your eye shadows, blushes, lipsticks, and other cosmetics depends on several factors. Among important considerations when deciding time to toss and replace beauty products: type of make up, how it’s been stored, and whether you’ve had an eye infection. Some make up shouldn’t be kept longer than 3 months, but you can hang on to other paints and varnishes for a couple years.

The United States doesn’t have any laws that require cosmetic manufacturers to include expiration dates on their packaging. Guidelines for when to discard make up are usually doled out by people who work within the cosmetics industry. The Food and Drug Administrationkeeps an eye on cosmetics manufacturers, and they provide some general advice for consumers.

To get maximum longevity from your make up, buy only cosmetics that haven’t been opened. When you get your goodies home, store them in a cool, dry place, away from direct sunlight. Always close the lids tightly after use.

Here are some common cosmetics and the recommended shelf life for each after it has been opened for the first time.

• Mascara: Toss your mascara after 3 months. Mascara has the shortest life span of all make up because the risk of transferring bacteria back and forth from your eye into the mascara tube is so great. If your mascara starts to dry out before its 90 days is up, throw it away. Don’t add water or saliva to your mascara to rewet it. Doing so will only increase your chances of getting an eye infection.

• Eye pencils: Eye pencils can be kept up to 2 years. To make sure you’re using a clean tip, sharpen before each application.

• Eye shadows: Keep your applicators clean and your liquid shadows should last 12 months. Powder shadows will keep 2 years.

  If you’ve had an eye infection, you’ll need to throw out all the eye make up and applicators you used from the time you developed symptoms. The virus or bacteria that caused the infection has probably taken up residence in your make up, so using those cosmetics again could cause you to develop another infection.

• Lipsticks: You can stow your tube lipsticks and your lip pencils for 2 years. As with eye pencils, sharpen your lip pencils before each use.

• Blushes and powders: Discard your cream blushes after a year, powder blushes and powders after 2 years.

  Think of your make up a bit like you do your food. If it smells weird, develops a film, or has a mold-green tint to it, it’s gone bad and needs to be tossed out.

• Foundations and concealers: Moisturizing foundations and stick concealers can hang around for 18 months. A 12-month shelf life applies to both oil-free foundations, which can dry out quickly, and liquid concealers.

  Using clean brushes and sponges will help lengthen the life of your cosmetics. Be sure and wash or replace your applicators frequently.

When you open a cosmetic for the first time, write the date on the product. It will help you keep track of how long you’ve had the make up so you’ll know when it’s time to throw it away.