The US Environmental Protection Agency (EPA) has issued a warning against consuming water that contains more than 0.4 parts per billion of perfluorooctanoic acid, or PFOA.
However, the decision has come up against criticism, as scientists have previously recommended levels no higher than 0.2.
The chemical, which is toxic to humans, is used in the manufacture of Teflon and non-stick products.
"This is essentially legalising unsafe exposure levels. Nobody should have to drink a cancer-causing Teflon chemical in their water," stated Richard Wiles, executive director of the Environmental Working Group.
DuPont, which produces PFOA, has agreed to stop manufacturing the chemical within the next six years.
In related news, a study conducted jointly by British universities found that pollutants in UK waterways could be responsible for a decline in male fertility.
