Concealer: They should last about a year. When the colors start to turn, that's when you know it's time to toss it. Continuing use can result in breakouts.
Face Powders and Blush: These babies can last up to two years before needing to replace them! The reason being is that powders contain a tiny amount of, if any, water so there is less of a chance of bacteria growth. Another indication of expiration is when your powders are too hard to pick up on the brush.
Mascara and Eyeliner: Mascara is the fastest product to expire; it should be replaced every 3-4 months. Every time you coat your lashes, dip the brush back in the tube, and coat again you are contaminating the tube with bacteria. Bacteria will grow in the closed off environment and will put you at risk for an eye infection! Eyeliner also has a shelf life of 3-4 months due to application around the mucous membrane. Pencils tend to last longer than liquids if you remember to keep sharpening them!
Eye Shadows: They have a surprisingly short shelf life, again due to application around the mucous membrane- about 5-6 months.
Lipstick and Gloss: Another shocker- they last up to about a year! They contain no water so they do not collect as much bacteria as expected. Since lip products are repeatedly exposed to the mouth area, toss them after about a year (especially if you've been sick).
Tools: Most tools will last YEARS if you take proper care of them. I recommend deep cleaning them every two weeks. When brushes aren't cleaned, they breed tones of bacteria and can cause breakouts. Spray alcohol on tweezers, lash curlers, or any other tools (not brushes!) to kill bacteria every few months.
-Patti, contributing elfette