Do you know what's in your makeup?

Girls 11 to 17 with an interest in science, math and makeup can enter the "Make Sense of Your Makeup" contest, which invites girls to create a design promoting safe, nontoxic cosmetics.

The winning design will be used as letterhead on correspondence to major cosmetic companies, asking them to sign a Compact for Safe Cosmetics and make sure their products are carcinogen-, toxin- and irritant-free.

"It teaches girls about advocacy -- that they can have a voice in the world," says Jennifer Stancil, executive director of the Carnegie Science Center's Girls Math & Science Partnership, which is sponsoring the contest. "It also exposes them to information about 'green' chemistry and opens their eyes to the many dangerous chemicals in products they use."

About 72 percent of mainstream makeup, including nail polish and facial moisturizers, contains phthalates, which have been linked to developmental and reproductive toxicity. About 61 percent of name-brand lipsticks contain lead -- with 33 percent of those containing lead exceeding the Federal Drug Administration limit for lead in candy, according to the Campaign for Safe Cosmetics. There currently is no FDA lead limit for cosmetics.

In a letter in November, U.S. Senators John Kerry, Dianne Feinstein and Barbara Boxer urged the FDA to test lipsticks for lead and set lead limits for lipsticks and other cosmetics.

The contest entry deadline is March 15. The top entries will be posted online, where girls can vote for their favorite design. The winner will receive a $250 scholarship, along with other prizes. For an application form and contest rules, visit www.BrainCake.org.