Though environmental groups have been warning us about the dangers of bisphenol--A (BPA) for years, a recent study by the National Toxicology Program that confirmed those findings has manufacturers of plastic bottles finally sitting up and taking notice.

BPA, which is a known endocrine disrupter, can leach into food products. In lab studies, it's linked to precancerous tumors and early puberty. Because BPA is in everything from plastic bottles to dental sealants to baby bottles, it's hard to avoid.

When the news broke about the most recent government study, Nalgene, a popular maker of plastic reusable drinking bottles, announced that they'd be pulling their bottles made with BPA off the shelves and replacing them with BPA-free versions.