Three US states are formally demanding that the Environmental Protection Agency (EPA) begin regulating PFAS “forever chemical” air emissions, as the toxic threat that the pollution poses to the environment and human health comes into sharper focus.

So far, federal regulators have focused on water pollution, but state environmental agencies in North Carolina, New Mexico and New Jersey last week filed a petition calling for the EPA to categorize four types of PFAS compounds as hazardous air pollutants and to begin regulating them under the Clean Air Act.

The petition comes after a Guardian investigation earlier this year found a Fayetteville, North Carolina, Chemours PFAS production plant is likely emitting much higher levels of the chemicals into the air than regulators and the company claimed. The air pollution is thought to be a driver of PFAS contamination in soil, water and food supplies across hundreds of square miles in the region.

However, a lack of federal rules makes it difficult for states to rein in air pollution, which is a “tremendous concern in our states and across the US”, the states wrote in their petition to Michael Regan, the EPA administrator.

“Adding these forever chemicals to the list of regulated pollutants addresses a gap in our regulatory authority and makes it possible to tackle a critical part of the PFAS life cycle: air emissions,” Elizabeth Biser, the secretary of the North Carolina department of environmental quality, added in a press release.