This January the Food and Drug Administration warned parents not to pour hot liquids into plastic baby bottles and also to discard bottles that get scratched. Otherwise, a potentially harmful chemical might leach out of the plastic. This warning was the agency’s first, tentative acknowledgment of an emerging scientific consensus: many widely used chemicals once deemed safe may not be.

But a warning was all the FDA could offer worried consumers. The agency does not have the power to force baby-bottle makers to stop using the chemical in question—bisphenol A, better known as BPA. Nor is the FDA alone. The Environmental Protection Agency’s administrator Lisa Jackson testified to Congress last September that her agency lacks the muscle to restrict the manufacture of BPA and other chemicals. The relevant law, the Toxic Substances Control Act of 1976, is simply too weak. It must be strengthened.

As the law stands, the EPA cannot be proactive in vetting chemical safety. It can require companies to test chemicals thought to pose a health risk only when there is explicit evidence of harm. Of the 21,000 chemicals registered under the law’s requirements, only 15 percent have been submitted with health and safety data—and the EPA is nearly powerless to require such data. The law allows companies to claim confidentiality about a new chemical, preventing outside evaluation from filling this data gap; some 95 percent of new submissions fall under this veil of secrecy. Even when evidence of harm is clear, the law sets legal hurdles that can make action impossible. For instance, federal courts have overturned all the EPA’s attempts to restrict asbestos manufacture, despite demonstrable human health hazard.

Consequently, of the more than 80,000 chemicals in use in the U.S., only five have been either restricted or banned. Not 5 percent, five. The EPA has been able to force health and safety testing for only around 200.

BPA is a case study of what has gone wrong. Although scientists identified potential problems decades ago, regulatory changes have been slow to follow. First synthesized in 1891, the compound became essential to the plastics industry as a building block of the polycarbonates in our eyeglass lenses, the polyesters in our clothes and the epoxy resins lining our cans. In the 1930s BPA was identified as a potent mimic of estrogen; it could bind to the same receptors throughout the human body as the natural female hormone. But the Toxic Substances Control Act explicitly allowed chemicals already employed at the time of the law’s passage—BPA and more than 60,000 others—to continue to be used without any evaluation for toxicity or exposure limits.

Nor did the act give the EPA the power to reevaluate chemicals in light of new information—such as the concerns about BPA that emerged in the 1990s. Researchers in a genetics laboratory noticed that a control population of mice developed an unusually high number of chromosomally abnormal eggs. The reason? BPA leaching from their plastic cages. From this serendipitous discovery, scientists began to explore anew BPA and other chemicals like it, known collectively as endocrine disruptors. Studies since then have linked BPA to asthma, behavioral changes, some cancers, cardiovascular disease, diabetes and obesity. The National Toxicology Program warned in 2008 that “the possibility that bisphenol A may alter human development cannot be dismissed.” Some health effects from BPA may even be passed from one generation to the next, and in contradiction to textbook toxicology, low doses of BPA may be as harmful as high doses. The Centers for Disease Control and Prevention has found that 93 percent of Americans have detectable levels of BPA by-products in their urine.

This problem is not confined just to BPA. New evidence is emerging about the dangers posed by the chemicals used to make plastics flexible or retard burning, among others. Although most chemicals are presumably safe, the lack of testing and ongoing bureaucratic delay imposed by existing legal requirements pose an unreasonable risk. It should not take decades for government agencies to catch up with the latest findings of science.

So the EPA is gearing up to try to regulate chemicals, establishing a list of “chemicals of concern” that echoes a similar list developed by regulators in the European Union under a recent law requiring that chemicals be tested for safety before being sold. Congress has begun to debate how to support this effort. It should begin by reforming and strengthening the Toxic Substances Control Act to require reviews of chemicals for safety, force manufacturers to provide adequate health data on any chemical under review, and empower agencies to restrict or ban the use of chemicals with clear evidence of harm. Industry groups such as the American Chemistry Council have recognized that such measures are needed to ensure public confidence in their products. Ultimately, the goal of oversight is simply to reflect the best available science, so that people are protected from the demonstrable risks posed by chemicals such as BPA and can rest assured that the chemicals industry says are safe really are.