I always start January

full of good intentions and lots of New Year’s beauty resolutions, but by the end of February they’re forgotten. One thing I look forward to is the annual cosmetic purge that always seems to happen once the new year is in full swing. (Besides, I love all the new products being launched for spring!)

Hoarding beauty products has a catch: they go bad. They stop performing as well as they used to; at worst, they can cause irritations or infections. Unopened, well-formulated cosmetics can remain stable for a couple of years at room temperature, but the clock starts once you bring a product home and it’s opened. Heat and humidity promote the growth of mold and yeast; that’s one reason the bathroom, though convenient, isn’t the ideal spot to store cosmetics. A better place is a cool, dry linen closet.

Since there is no real American labeling regulation on expiration dates for most cosmetics – look for the obvious signs, such as dried mascara or separated foundation – it can be tough to tell when something’s past its prime. Follow some beauty-protecting tips on when to throw away what:

Mascara: ¼ year
Foundation: ½ year
Concealer: 1-1½ years
Powder: 2 years
Blush and Bronzer: 1½ years
Cream Blush: 1-1½ years
Eye Shadow: 2 years
Pencil Eyeliner: 2 years
Liquid Eyeliner: ¼ year
Lipstick and Lip Gloss: 2 years
Lip Liner: 2 years+
Nail Polish: 1 year
Makeup Sponges: Wash after each use, then throw away after a month

Face Makeup
Toss-it time: Six months for liquids; two years for powders

Insider info: You increase the odds of bacterial growth, breakouts or irritation when you repeatedly dip your brushes and fingers into liquid foundation. Also, as it ages, foundation can go on unevenly, creating a streaky, inconsistent finish. Oils rise to the top, and the consistency thickens. Powders present less of a problem because bacteria can’t grow where there’s no water. However, over time, powders with botanical ingredients such as aloe or jojoba can become harder to blend and are more likely to crumble as their trace amounts of water evaporate. With many of the mineral powders and the brushes you use for them, if you’re putting a lotion or cream on first then applying the powder, then your brush must be cleaned often, as bacteria will grow there as well and get into the powder. Even tube makeup sucks air backward when used, so keep a nose out for smell and watch for changes in consistency.

Toss-it time: Three months or less

Insider info: A mascara tube is a dark, wet environment; the perfect breeding ground for bacteria. Preservatives in mascara only work for so long, and three-month-old mascara just doesn’t perform well; it’s chalky and powdery, and any lengthening or thickening fibers often separate from the fluid, so the mascara stops going on in a smooth, even coat. To avoid hastening the demise of your mascara, never pump the wand – that pushes air into the tube, causing it to dry out faster. Instead, slowly draw out and twist the brush to scrape the tube’s interior. When good mascara goes bad it can cause all sorts of problems, you can even develop a sty from the mascara wand.

Eyeliner and Eye Shadow
Toss-it time: Liquid eyeliners, three months; cream eye shadows, six months; pencil eyeliners and powder eye shadows, two years

Insider info: As they do with mascara, bacteria tend to flourish in liquid-eyeliner tubes, and the product dries out. Pencil eyeliners have a longer shelf life because you can create a fresh, clean surface each time you sharpen them. (Just be sure to regularly sanitize your sharpener with rubbing alcohol.) Powder shadows, like pressed powders, are less prone to contamination because they, too, lack water (if you wet them, toss after six months). But aging eye shadows have performance issues: They get packed down, making it harder to pick up pigment with your brush.

Lipstick and Lipliner
Toss-it time: Lipstick and gloss, two years; lip liner, two years or more

Insider info: Lipsticks’ water content makes them potential mini reservoirs of bacteria. No surprise, they also dry out with age, which means they no longer look creamy on the lips. The newer long-wearing formulas have an even shorter life span since they often contain ingredients that evaporate more quickly than creamier formulas. Pencil lip liners, like eyeliners, may last a little longer, since putting them through a sharpener removes the old surface.
So in review: Accept that you’re going to be discarding items that you shelled out for but never used. Pitch anything that smells off, has separated or has gone past suggested times above. Pitch it if you don’t like the texture, the color or never use it.