It took years to find makeup products that help you look and feel your best. But many of the staples you trust for their beauty benefits are harboring ugly ingredients with potential health risks—think petroleum byproducts, chemical preservatives, and synthetic colors and fragrances. Because women apply an average of 12 beauty products each day, cumulative exposure to toxins can be a serious concern. “There are tons of wonderful nontoxic products on the market; it's just about finding the product that works best for you,” says Los Angeles–based celebrity makeup artist and natural-beauty expert Lina Hanson, author of Eco-Beautiful (Rodale, 2009).  Use this guide pinpointing the worst offenders—and safe, effective alternatives—to jump-start your makeup overhaul.