Despite 40 years of regulatory effort, chemical regulation in the United States has been a dismal failure, and our current law – the Toxic Substances Control Act (TSCA) – deserves much of the blame for this regulatory dysfunction. When Congress enacted TSCA, the final legislation reflected a deal under which chemicals then on the market were “grandfathered” in, while new chemicals would be subject to a quick review by the Environmental Protection Agency (EPA). But experience shows that a vast majority of those reviews are based on inadequate data.