[Feature] Rules of evidence
A common plastic additive called bisphenol A (BPA) has become the focus of major controversy. It can weakly mimic the human hormone estrogen, and leach out of products—including plastic drinking bottles and medical supplies—in small quantities. As a result, some companies and governments have moved to remove BPA from certain products, even though there is still fierce debate among regulators over BPA's safety. Some researchers say that debate is being ill-served by rules developed in the 1960s and '70s, in response to a chemical testing scandal, that are designed to make sure regulators consider only the strongest evidence. But the critics argue the rules now prevent regulators from considering high-quality, cutting-edge academic studies that don't follow the rules. A U.S. government–funded initiative is now trying to bridge the divide. Author: Warren Cornwall