But researchers say focusing on the environmental impacts and potential health harms of the finished products alone hides their actual environmental impact. Manufacturing Teflon and other fluoropolymers uses other, more dangerous PFAS chemicals. These compounds are known to contaminate the environment surrounding manufacturing facilities, said Rainer Lohmann, a professor of oceanography at the University of Rhode Island.

"Basically, anywhere where there's a major fluoropolymer producer, they seem to have succeeded in contaminating the entire region with their production process," he said.

The ministry's move to remove fluoropolymers from its proposed rules suggests those industry lobbying efforts have worked, MacDonald said. Using a study with self-declared ties to the chemical industry to back up the ministry's decision to exclude fluoropolymers "just kind of shows a little bit of what's happening behind the scenes in terms of where the government is taking the industry's word," she said.