And seemingly more-straightforward labels calling items are “natural,” “organic” or “hypoallergenic” can be misleading. That’s because the FDA hasn’t established official definitions for these terms. “So companies can use them on cosmetic labels to mean anything or nothing at all,” according to the FDA’s Web site.Critics note that consumers use dozens of personal-care products daily and argue that potentially hazardous chemicals shouldn’t be used in the first place. The European Union has banned more than 1,000 ingredients considered unsafe for use in cosmetics. The FDA has banned nine.

There also are concerns about the increased use of nanotechnology—compounds thousands of times smaller than the width of a human hair. Because of their size, there’s potential for these nano-sized ingredients to penetrate human cells and tissues. The technology is already being used in anti-aging creams and sunscreens—but the labels don’t have to specify its use. In the absence of stricter regulations, California lawmakers adopted the Safe Cosmetics Act of 2005. It requires cosmetic manufacturers to give the state a list of ingredients in their products that can cause cancer or reproductive harm. Washington has a program for reducing exposure to select hazardous chemicals, but nothing specific to safeguards for cosmetics.