Label: Biodegradable
Your preferred hair conditioner may boast that the liquid inside is "biodegradable." While that certainly sounds eco-friendly, what exactly does it mean? According to the Federal Trade Commission's guidelines, created in conjunction with the EPA, a product labeled "biodegradable" should decompose "into elements found in nature within a reasonably short period of time." For liquids that go down the drain, decomposition should finish during the waste-water treatment process.

The problem? Because the FTC doesn't review products for safety before they're sold, biodegradable claims may go unsubstantiated until a complaint or tip is filed, explains Mike Davis, attorney for the FTC's Bureau of Consumer Protection.

To complicate matters, there's even disagreement over what any given sewer treatment system can render safe. While the FTC says most shampoos and similar products degrade in such systems, reports show that some chemical ingredients still end up in streams, rivers, and bays. A 2007 study released by the Environmental Working Group (EWG) identified triclosan, phthalates, and bisphenol A, three potentially harmful chemicals used in personal care products and their packaging, in treated wastewater in the San Francisco Bay. "These chemicals are known to take a long time to break down," says Rebecca Sutton, Ph.D., a chemist with the EWG. "Our wastewater systems aren't designed to treat them."

Bottom Line
"Do your own research," says Bill Walker, a vice president at the EWG. You can log on to "Skin Deep," the group's safety guide, at cosmeticsdatabase.com, and discover which chemicals build up in humans and animals with repeated exposure.