using make up that is over a year old is a bad idea. Even if the make-up is not opened bacteria will grow inside of it. Makeup bags contain products that are used often and can become a breeding ground for germs and bacteria. Dermatologists say a messy makeup kit can lead to infection, allergic reaction, and even acne. here is the shelf life for the following:
* Mascara: Mascara lasts 3-6 months and is the most prone of all makeup to harbor bacteria because the wand is constantly being dipped. A general rule is anything that is a liquid has a shorter life.
* Concealer: Has a life of about 18 months due to emulsion (the ingredients will begin to separate). Also, remember you’re generally using concealer to cover blemishes, which can be more sensitive and prone to infection than other parts of your face.
* Liquid Foundation: You should never use liquid foundation after more than one year. Always use a sponge, and not your germ-laden fingers! If the foundation separates or smells bad, throw it out.
* Loose Powder: This item can last for years.
* Eye Shadow: Lasts 12-18 months if it is a cream, 2 years if it’s a powder.
* Lip Pencil: Can last 3 years due to the wood and wax. Remember to sharpen and cover between uses.
* Lipstick: Can hold up for 2-3 years, but if there is a color change or rancid smell, throw it out.
* Lip gloss: Don’t keep more than 18 months due to a different formulation chemical composition and the same dipping problem as mascara.