Check out this great article on when it’s time to throw out your cosmetics. Cosmetics have a limited shelf life. Acne and eye infections could result from using expired or contaminated cosmetics. I personally do the smell test and I know right away!
Also, here’s a site for a cosmetic calculator, which helps you to determine the manufacture date of cosmetics or perfume by the batch code or lot number, and provides general information about product shelf life.