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At least once a year, I take some time to go through all of my bathroom drawers and cabinets, taking inventory and throwing away a slew of cosmetic and hair products. I'm always surprised by the quantity of makeup I had long forgotten about -- from Urban Decay palettes to dozens of lipsticks in every shade. The question pops into my mind: "Is this expired yet?" This question has lead me down a rabbit hole of researching the shelf life of different makeup products.

Yes, makeup does expire, and most products expire much faster than I expected -- making me realize I'd been using them well past their prime. I'm not alone, though. According to one study, nearly 98% of participants said that they've worn makeup past its expiration date.

It's hard to throw away your favorite lipstick or an eyeshadow palette that still looks like it's in great shape, especially considering how expensive some brands are. However, using products past their expiration date comes with health risks, including increased chances of eye and skin irritation, bacterial growth and possible infection.

To avoid any complications or reactions, it's important to practice good makeup hygiene. Here's a breakdown of when different cosmetic products expire and what can happen if you continue using them past that date.

Read More: 10 Easy Ways You Can Boost Your Eye Health Every Day

There's a common misconception that makeup is safe to use past its expiration date, but that isn't always the case. The potential of breakouts, skin reactions and infection is too high to ignore, so it's important to be mindful of how long your makeup has been open to avoid health hazards.

Powder products and water-based products have different shelf lives. Powders, like blush or bronzer, are safe to use for up to two years if properly stored and free of any moisture. Water-based makeup products, like liquid foundation, are very susceptible to bacterial growth, giving them a shorter shorter shelf life of up to one year. In general, makeup products last about one year from the date of manufacture before expiring, according to the Mayo Clinic. However, there are variations. Below is a breakdown of how long makeup lasts and when to toss it.

Here's the typical shelf life for eye makeup and products:

Here's the usual lifespan for skin cosmetics:

With so many products applied to or near your skin, it's crucial to know when they should be thrown out.

These are just general rules of thumb, as many products can expire faster if not properly stored or if they're exposed to moisture. It's best to discard any products that have changed color, dried out, cracked, separated, clumped, thickened or developed a strange odor.

Cosmetics are not required to have expiration dates printed on labels in the US. The good news is that many products do anyway.

To find them, first examine the label and see if you can find an open jar icon -- known as the Period After Opening (PAO) symbol -- which will have a number printed inside it. This icon determines the shelf life of the product. For instance, if there's a 12 printed within the jar icon, the product is safe to use for a year after you've opened it. If there's a 24, the makeup is good for up to two years after opening.

If you don't see a PAO symbol, you can use the above recommendations to determine how long you can use the product before it expires.

Using expired makeup can result in various health issues and adverse reactions, including:

With good hygiene and habits, you can greatly reduce the likelihood of being exposed to bacteria, infection or adverse skin and eye reactions. Here are some additional tips to keep your eyes and skin healthy when applying makeup and cosmetic products.