For much of the 20th century, asbestos — dubbed a “miracle mineral” for its strength and fire resistance — was ubiquitous in buildings, homes, and consumer products. But beginning in the 1970s, as the material was shown to cause cancer and respiratory illnesses, a combination of tort liability and regulation curbed its use in the U.S. For many, that awakening has been too little, too late. Thousands of Americans continue to die each year from asbestos-related diseases.

Today, we may be facing the next asbestos: Per- and polyfluoroalkyl substances, or PFAS. Stain resistant, waterproof, and grease repellant, PFAS are widely used in nonstick cookware, food packaging, clothing, furniture, and fire retardants. Their best-known applications include Teflon, Scotchgard, and GORE-TEX. But for more than a decade now, PFAS have been linked to increased cancer risk, reduced fertility, immune system suppression, and stunted growth and learning.

Known as “forever chemicals” because they do not easily break down, PFAS have found their way into drinking water supplies and into a variety of foods, and almost all Americans have detectable levels of PFAS in their blood. Yet federal regulators have taken few measures to protect citizens from PFAS’s harms — and when they have acted, they’ve been seemingly a step behind at every turn. That must change.

To their credit, manufacturers have taken some steps to respond to concerns regarding PFAS. Industry largely phased out two of the most commonly used and extensively studied PFAS — perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) — by 2002 and 2015, respectively. But both of these substances continue to seep from contaminated sites into the drinking water supplies of millions of Americans. And, for the most part, manufacturers simply replaced PFOA and PFOS with other PFAS chemicals that have similar structures, similar characteristics, and — scientists fear — similar health risks.

In theory, several environmental statutes — including the Safe Drinking Water Act and the Toxic Substances Control Act — could be used to address at least some aspects of the problem. However, federal regulators have been slow to respond. In 2016, the U.S. Environmental Protection Agency advised drinking water system operators to take action whenever combined PFOA and PFOS concentrations exceed 70 parts per trillion. Operators were advised to conduct further sampling, inform consumers of the elevated concentrations and potential dangers, and limit the public’s exposure to tainted water supplies. But the agency’s advisories govern only those two chemicals and are not enforceable. In February 2019, the EPA announced that, by the end of the year, it will start the process for developing enforceable standards for PFOA and PFOS levels in drinking water, though it’s unclear when the work will be completed.

As the EPA drags its feet, some states have begun to develop their own regulatory standards — and to file lawsuits against industry and the U.S. Department of Defense, which owns or operates hundreds of sites contaminated by PFAS-containing firefighting foam. In Congress, bipartisan support for legislative action is building. More than 30 PFAS-related bills have been introduced on the Hill, including proposals requiring the Defense Department to address water contamination at military bases and EPA to establish enforceable standards for PFOA and PFOS in drinking water within two years.

Although these developments are encouraging, PFAS contamination is a multifaceted problem that calls for a multifaceted response. So, as Congress pursues legislative solutions, there are several things it should keep in mind.

First, because PFAS comprises thousands of substances, a chemical-by-chemical approach to regulation is likely to fail. Hundreds of scientists have concluded that the structural similarities between PFOS and PFOA — for which the evidence of toxicity is clear cut — and other PFAS warrant caution in the use of all PFAS. Regulation of the various PFAS chemicals should not require definitive evidence of each individual substance’s toxicity.

Second, Congress should address not only the threat of present-day exposure to PFAS, but also harms from past exposure and risks of future exposure. It will be essential to identify and redress harms to those who have already been exposed to PFAS, to clean up contaminated sites and secure safe water supplies, and to prevent future contamination. In the cleanup process, establishing drinking water standards is only a first step. Water suppliers will likely require financial and technical assistance to achieve those standards — and basic fairness suggests that the companies responsible for the contamination should bear the costs. To prevent future contamination, Congress should limit PFAS use and promote non-PFAS alternatives.

Third, although drinking water contamination is the most pressing and significant pathway for PFAS exposure, people can also be exposed to PFAS through their work environments, contaminated foods, foods wrapped in PFAS-treated packaging, and various consumer products. It will be important to assess the risks associated with these alternative pathways and to develop strategies to deal with them.

The broad bipartisan support for action on PFAS reflects the urgency and importance of the substances’ known health hazards. Congress must act quickly — and wisely — to make sure PFAS doesn’t become the next asbestos.

Albert C. Lin is a Martin Luther King, Jr. Professor of Law and Muir Institute Fellow at the University of California Davis, School of Law, where he specializes in environmental and natural resources law.