Cosmetics aren’t required by law to have expiration dates, so you can’t always consult a label to determine if your makeup is still good. Even dated items may be misleading because a product can expire long before the printed date if it's not stored properly.
From the time you open that bottle of foundation or tube of mascara, the life and effectiveness of the product decreases. While preservatives kill some bacteria, FDA studies show that a little bacteria is present in makeup even before you buy it, and whenever you open it or touch it, you’re introducing more. At some point, aging cosmetics lose their ability to fight bacteria no matter how carefully you store them.
Here are some tips that will extend the shelf life of your cosmetics and protect you from infection — plus some advice on when it’s time to replace everything from eye liner to lipstick. (Text: Laura Moss)