The US government is proposing the first-ever national standard for drinking water to protect Americans from dangerous “forever chemicals”.

The plan, laid out by the Environmental Protection Agency (EPA) on Tuesday, would establish legally-enforceable levels for six per- and polyfluoroalkyl substances, or PFAS, that are known to occur in drinking water.

PFAS are a type of manufactured chemicals that are linked to severe health problems, including cancer, if people are exposed over long periods of time.

The proposed regulation would require public water systems to monitor for these chemicals, and to notify communities if PFAS contamination exceeds the standard, and also take action to fix the problem.

EPA Administrator Michael S. Regan said the potential rule could prevent tens of thousands of illnesses related to the hazardous substances.

Actor and environmental activist Mark Ruffalo said that the Biden administration was “putting our communities ahead of the polluters”.

“My message to polluters is simple: after poisoning your workers and neighbors for decades, it is time to make our public health, not your profits, our top priority. My message to communities devastated by PFAS pollution is equally simple: help is finally on the way,” he said, in a statement.