Expiration Dates Matter: When To Toss Your Beauty Products

NEW YORK (CBSNewYork) -- Beauty products can be expensive, so it's no surprise that most of us try to squeeze every last drop out of them.

But experts warn, there are dangers to using makeup that's past its prime. The very products that are meant to enhance your beauty can do the complete opposite if used past their expiration date.

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The truth is, expiration dates serve a bigger purpose than merely forcing you to buy more products, CBS2's Alex Denis reported. Old makeup works less efficiently and can do major damage to your skin because of a build up of excess bacteria.

Beauty expert Bennett Jason says most products have what's called a "period after opening" symbol.

"There is an open little product marker that has the amount of time, once it's opened to use it," Jason said.

If you can't locate the symbol, follow these averages -- mascara should be tossed every three months along with liquid or gel eyeliner. Lip gloss should be switched every nine months, and creamy products, like moisturizer, concealer and foundation, will show signs when it goes bad.

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"When the formula begins to separate," Jason said.

Lipsticks and liners typically keep color for 12 months. Powders, including blush and bronzers, stay fresh anywhere from 18 to 24 months and nail polish can up to last two years.

To help keep things fresh, use cleaners. Brushes should be cleaned once a week, and you can prolong the life of your creamy products by keeping them in the fridge to keep the formula intact.