Drinking water throughout the United States will have to meet new standards limiting its concentration of PFAS, toxic chemicals that harm human health and don’t break down in the environment, President Joe Biden’s administration announced on Tuesday.

PFAS, which stands for per-and polyfluoroalkyl substances, are a class of thousands of harmful chemicals that are ubiquitous in consumer products. Used since the 1940s, they are prevalent in goods that are non-stick, water-resistant and flame-retardant, including cookware, furniture, carpeting, clothing and firefighting foam.

The chemicals also threaten the environment because PFAS never break down, and consuming even minuscule amounts of these substances threaten human health, according to the U.S. Environmental Protection Agency. Exposure has been associated with deadly cancers, liver and heart problems and developmental and immune damage to infants and children, the EPA said.

“People can be exposed to PFAS through drinking water or food contaminated with PFAS, by coming into contact with products that contain PFAS, or through workplace exposures in certain industries,” the EPA said in a press release.

The standards finalized this week set enforceable limits – called maximum contaminant levels, or MCLs – for several kinds of PFAS. The MCL for two of the most-researched kinds of PFAS, called PFOA and PFOS, is now 4 parts per trillion.

“This standard will reduce exposure from these PFAS in our drinking water to the lowest levels that are feasible for effective implementation,” the EPA said in a press release.

The agency is limiting other kinds of PFAS – PFNA, PFHxS, and “GenX Chemicals” – at 10 parts per trillion. And it is imposing a limit for mixtures of two or more PFAS varieties. However, the EPA made clear that the goal for PFOA and PFOS concentrations in drinking water should actually be zero.

“This reflects the latest science showing that there is no level of exposure to these contaminants without risk of health impacts, including certain cancers,” the agency said.

Along with the new regulations, the Biden administration is making $1 billion in new funding available to help states and territories with PFAS testing and treatment of public water systems and to assist private well owners with addressing contamination.

An estimated six to 10 percent of the 66,000 public drinking water systems in the country may have to take action to meet the new standards, according to the EPA. All systems have three years to comply with initial monitoring requirements and must inform the public of the PFAS levels found in the drinking water.

When high detections are found, providers will have to take action, including using granular activated carbon, reverse osmosis, and ion exchange systems to remove the contamination.

“For decades, the American people have been exposed to the family of incredibly toxic ‘forever chemicals’ known as PFAS with no protection from their government,” Environmental Working Group President and Co-Founder Ken Cook said in a statement. “Those chemicals now contaminate virtually all Americans from birth.”

He continued: “There is much work yet to be done to end PFAS pollution. The fact that the EPA has adopted the very strong policy announced today should give everyone confidence that the Biden administration will stay the course and keep the president’s promises, until the American people are protected, at long last, from the scourge of PFAS pollution.”