PRACTICAL VIEW : How to Tell If Makeup Is Past Its Prime

Unlike coffee, makeup is not good till the last drop. Experts suggest the following expiration dates:

* Foundation has a two-year shelf life and begins to thicken and separate as it ages. Storing it in the refrigerator, with masking tape around the cap, helps prevent evaporation.

* Loose powder has a 10-year shelf life, but a compact is good for only about one year. Aging signs include flaking and shininess, which is caused by facial oils; they can be removed by gently rubbing a paper towel across the cake.

* Lipstick, cream rouge and cream eye shadow are good for about one year. Aging signs include beads of “sweat.”

* Mascara is more controversial. Some experts say the “wand” type is good for only three weeks, others say three months. Aging signs include clumping and a bad odor, which may indicate the growth of harmful bacteria. Cake mascara, however, lasts indefinitely because the brush dries after use.

* Powder eye shadow has a shelf life of about two years.

* Lip- and eye-liner pencils are good for about two years. Aging signs include dryness, but frequent sharpening will remove bacteria buildup and restore moisture.

One of the best ways to keep cosmetics bacteria free is to use washable brushes instead of bacteria-carrying puffs and sponges, says Pablo Manzoni, international creative director of makeup for the La Prairie skin-care collection.