The degree to which BPA poses a direct health risk continues to be debated. But China, Canada, Japan, the European Union, more than half a dozen U.S. states, the District of Columbia, and several other local and national governments have already restricted some uses of BPA, particularly in children's products, and this year about 17 states are expected to introduce similar legislation. So even if BPA is less of a risk than many people think, demand for alternatives is increasing. While there are currently no federal restrictions on BPA use, both the U.S Environmental Protection Agency (EPA), which has labeled BPA "a chemical of concern," and the Food and Drug Administration (FDA) have issued statements of support for the use of BPA alternatives.

So what are these BPA-free materials and what do we know about them?

Glass, ceramics, and stainless steel are alternatives for some uses of polycarbonates, but plastics have obvious attractions. And avoiding many uses of BPA—can linings, paper—will require some kind of new polymer, or products will have to be redesigned to perform as desired without, for example, a plastic liner or coating. Companies are pursuing both strategies.

Then there are the new plastics on the market for BPA-free bottles, can liners, and other such products. The Environmental Protection Agency (EPA) also has an effort underway through its Design for Environment program to examine the alternatives to the BPA-based thermal papers used in receipts, currency, and other similarly printed papers. But because the U.S. system of regulating chemicals relies primarily on information supplied by a material's manufacturer, we know relatively little about these new plastics.

For example, among the more widely used plastics now marketed as "BPA-free" is Tritan copolyester, made by the Eastman Chemical Company. According to Eastman, sales of Tritan copolyester quadrupled between March of 2009 and March 2010. But currently the available information about this product's chemistry comes from its manufacturer. The Eastman Chemical website offers Material Safety Data Sheets (MSDS) for 23 different compounds sold under the Tritan copolyester name (each intended for different product applications). The MSDS sheets list no toxicity data and note that the compounds' environmental effects have not been tested.

In May 2010, Eastman released test results showing several of the chemicals that make up Tritan copolyester to be free of both BPA and any endocrine-disrupting activity. But no other environmental or toxicity information or the final product's other chemical ingredients is included.

The point is not to single out the Eastman Chemical Company or Tritan copolyester, which may be entirely environmentally benign, but to highlight the dilemma we're in when it comes to assessing the safety of new materials. The same could be said of any number of new materials used in hundreds of consumer products. Under the Toxic Substances Control Act (TSCA), the U.S. law that regulates chemicals in commerce, it's entirely permissible to launch a new material into high-volume production without disclosing its precise chemical identity or any information about its toxicity. This makes it impossible for the public to assess product safety independently of manufacturer claims. And currently, despite EPA and FDA policies that support "safe" alternatives to a chemical of concern like BPA, neither federal agency conducts safety testing of new materials destined for consumer products before they come on the market.