Telling when makeup is past its prime can be very hard, as there is no expiration date on it, but one way to be sure is that if a product is damp or wet it is going to to have a shorter shelf life.

“The things that are most likely to give you an infection are creams, or things that are wet or dark or damp,” the New York Daily News quoted Dr Andrea Thau, a New York optometrist and a spokesperson for the American Optometric Association, as telling MSNBC.

The FDA recommends being careful with cosmetics, especially products applied around the eyes.

Using an old mascara can lead to some unsightly skin issues, including blepharitis, an itchy inflammation of the eyelid, and conjunctivitis, also known as “pink eye”. Experts recommend dumping eye makeup after three months, getting rid of creams, liquids or moisturisers after about a year (less if you are constantly sticking your fingers in the pots), and tossing powders, pencils, lipsticks or gloss after about 18 months.

Once you open a product, it is a countdown to contamination, so try to remember when you started using it so that you can toss it.

Stay away from makeup store testers! If you must try out a colour, use a clean cotton swab, recommends the FDA’s cosmetic information page.  Still, don’t forget that you are sticking that swab into a potential pot of germs.

Don’t apply eyeliner inside your lashline, said Thau.

This beauty faux pas interferes with your meibomian glands, which help in the production of tears. If the glands can’t secrete properly, you could get dry eye.