There are makeup users who are not aware on the expiration of makeup foundations they use. Once a foundation has expired, do yourself a favor. Toss it away regardless the brand and price before it cost your whole face. Continuously using it will only cause harm than beauty to your skin. Also, the efficiency of active ingredients become compromised over time. Your skin may react and cause you skin lesions, rashes, blisters, acne or even redness and swelling.

For your own safety, it is best to learn determine if the foundation you use is already expired. In case you don't know, here are some ways on how to figure out:

Liquid Foundation:
Most often, first thing you will get to notice is the odd scent. The original scent is replaced with a mild sour smell. Once you noticed the change in scent, just stop using. Also, when oils rise to the top and there is separating formulas, your liquid foundation is supposed to be thrown.

Powder Foundation:
Most of the time, no manifestation in scent once a powder foundation is out of date, but will initially notice in texture. It hardly adheres on face regardless you wear primer. Depending on the ingredients, a powder foundation may get hard like stone on the inside the compact when expired or may become softer. Either way, your face appears dry and powders crumble on your skin with an expired powder foundation on.

Cream Foundation:
Just like any liquid foundation, you can tell by the smell if your cream foundation is already expired. Normally for creams, the consistency thickens and it becomes hard to blend.

Most of the time, there is an icon below the product which determines the number of months before it expires. The icon looks like the photo below:

If you see any sign of expiration mentioned above, well its toss-time!