Read the full article by Tom Perkins (The Guardian)

“The US Environmental Protection Agency (EPA) office responsible for protecting the public from toxic substances has changed how it defines PFAS for a second time since 2021, a move critics say they fear will exclude thousands of ‘forever chemicals’ from regulation and largely benefit industry.

Instead of using a clear definition of what constitutes a PFAS, the agency’s Office of Pollution Prevention and Toxics plans to take a ‘case-by-case’ approach that allows it to be more flexible in determining which chemicals should be subjected to regulations.

Among other uses for the compounds, the EPA appears to be excluding some chemicals in pharmaceuticals and pesticides that are generally defined as PFAS, current and former EPA officials say, and the shift comes amid fierce industry opposition to proposed limits on the chemicals.

The approach puts the toxics office at odds with other EPA divisions, other federal agencies, the European Union, Canada and most of the scientific world. The definition is likely to generate confusion in the chemical industry and within the agency, current and former EPA officials say.

‘This is not a new definition – it is a lack of definition, and it makes no sense,’ said Linda Birnbaum, a former EPA scientist and head of the National Toxicology Program. ‘It is just going to lead to terrible confusion.’

PFAS, or per- and polyfluoroalkyl substances, are a class of about 15,000 compounds most frequently used to make products water-, stain- and grease-resistant. They have been linked to cancer, birth defects, decreased immunity, high cholesterol, kidney disease and a range of other serious health problems. They are dubbed ‘forever chemicals’ because they do not naturally break down in the environment.

In a statement to the Guardian, the EPA said its latest definition was more ‘expansive’ than the previous. Its approach was designed ‘to focus on substances most likely to be persistent in the environment, including some chemical substances whose structures or sub-structures resemble, at least in part’ more thoroughly studied PFAS compounds, like PFOS and PFOA.

But public health advocates warn that all PFAS are persistent in the environment and all that have been studied are toxic, and for those reasons many are calling on the government to largely restrict the entire chemical class.

Speaking on condition of anonymity for fear of reprisal, a current EPA employee in the toxics office said the chemical’s definition has been evolving for several years. The employee said they first learned of the latest change in public comments made by Michal Freedhoff, a Biden-appointed toxics office administrator.

It is unclear what prompted the latest shift, the employee said, but it comes as the EPA implements its ‘PFAS strategic roadmap’ to help rein in PFAS pollution. The shifting definition complicates that effort, the employee said.

‘EPA can’t get its act together on what PFAS are,’ they added. ‘To regulate PFAS, you have to agree what are and are not PFAS.’

The most widely used, inclusive definition, and that proposed by the Organization for Economic Cooperation and Development (OECD), defines any chemical with one fluorinated carbon atom as a PFAS. That could include tens of thousands of chemicals on the market and some public health advocates say a narrower definition is warranted.

The EPA toxics office in 2021 implemented a ‘working definition’ that defined PFAS as chemicals that have ‘at least two adjacent carbon atoms, where one carbon is fully fluorinated and the other is at least partially fluorinated’. It covered about 6,500 PFAS, but the toxics office expanded the definition as the industry exploited loopholes.

The employee said debating the definition distracts from the more important effort to quickly regulate PFAS that are already known to be found in people and animals.

Current and former EPA employees say the agency is not defining some fluorinated chemicals used in pesticides as PFAS at a time when research has discovered their widespread use in agricultural products. The agency also excludes some ‘ultra short chain’ PFAS refrigerants, which are defined as PFAS by the European Union but not the toxics office, said Tim Whitehouse, a former EPA attorney now with the Public Employees for Environmental Responsibility nonprofit.

He said the stricter regulations in Europe have forced the industry away from the kind of PFAS refrigerants produced by Chemours, a chemical manufacturer with a plant in North Carolina. Chemours opposes defining the refrigerants as PFAS ‘because it is going to destroy their market’ as it has in Europe, Whitehouse added.

The consequences of the EPA’s narrower definition have already been felt in North Carolina’s Cape Fear basin, which is contending with decades of Chemours pollution. A 2019 citizen group petition asked the EPA to conduct studies that would shed light on the health impacts of 54 PFAS compounds found in human blood and water in the region.

In the agency’s December 2021 response, it declined to test for 15 chemicals it said ‘do not meet’ the toxics office PFAS definition.

The change also creates uncertainty for chemical companies who are producing substances that may or may not fall within the definition, which Kyla Bennett, a former EPA official now with PEER, characterized as ‘insanely frustrating’.

‘The EPA claims they switched to a case-by-case basis to remain flexible, but in the past it has said, “We want to provide regulatory certainty,” but this is the furthest from regulatory certainty that I can think of,’ she added.

The White House’s Office of Science and Technology coordinates among federal agencies could provide guidance to federal agencies on which definition to use, but it has failed to do so, Bennett said.

‘The bottom line is the EPA has one job and that is to protect human health and the environment, and when it comes to PFAS they are not,’ she added.”