PFAS pesticides approved after EPA adopts new toxicity definition (Jul 2026) Trump officials kill proposed rules for PFAS-contaminated sewage fertilizer. EPA tosses out scientific research carried out under Biden and says toxic sludge not a significant threat to public Article

[Michael Harrop]

https://www.cnn.com/2026/07/10/health/pfas-pesticides-industry-influence-wellness
https://www.theguardian.com/environment/2026/jul/20/trump-pfas-sewage-farm-fertilizer

In mid-November 2025, the EPA changed a page on its website that originally included a definition for PFAS chemicals endorsed by more than 150 leading PFAS researchers, the European Union and nearly half of US states.

The nuance was important: Instead of considering pesticides with any type of carbon-fluoride bond as potentially toxic, the agency declared single carbon-fluoride bond chemicals were no longer PFAS and therefore “safe.”

“EPA-approved single fluorinated compounds are not forever chemicals, they are not PFAS, and do not pose any risks of concern when used as labeled,” the page now states.

The agency’s deviation from the global scientific consensus in defining PFAS reflects the “deep level of industry capture at the agency and the willingness of political appointees to succumb to that pressure,” Munoz told CNN.

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[SFBayFMT5]

The nuance was important: Instead of considering pesticides with any type of carbon-fluoride bond as potentially toxic, the agency declared single carbon-fluoride bond chemicals were no longer PFAS and therefore “safe.”

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Well, chemically speaking the new definition of PFAS is more correct. PFAS stands for "perfluoroalkyl substances", and the prefix "per" means "all", so for instance perfluorooctane by definition has all C-F bonds and no C-H bonds. However it makes sense to include molecules where only one hydrocarbon group is perfluorinated, as this part of the molecule can still persist even once the rest has broken off, so e.g. perfluorooctyl-X where one of the C-F bonds is replaced by another group that may also have one or more normal hydrocarbon chains coming off of it is included (*). However if every carbon in the entire molecule has at least one C-H, then it's hard to argue that it's a PFAS.

However, "not PFAS" certainly doesn't mean nontoxic! Most of the extremely potent toxins in nature, such as the protein ricin, don't have a single fluorine at all, and neither do cyanide, any of the heavy metals such as mercury, etc. And in some cases one fluorine is worse than several, e.g. monofluoroacetic acid is very toxic in ways and at doses that have nothing to do with its acidity, while trifluoroacetic acid is mostly only a problem at high concentrations from being a much stronger acid than acetic acid itself.

This shows the difference between government and science--in government, headings that chemicals fall under have more to do with what reputation they have with which agencies than any property of the substances themselves.


(*) Even this definition would include drugs such as Prozac with a -CF3 group, whether to call them PFAS is quite debatable.

 

[SFBayFMT5]

I actually just read the article you linked, and both newly approved pesticides contain at least four C-F bonds and one -CF3 group. So it seems nobody is seeing clearly--the pesticides don't fit the new definition, at least if the article is reporting it correctly, and it's still unclear what a PFAS actually is.