The Environmental Protection Agency approved three new chemical pesticides on June 30, and environmental watchdog groups immediately challenged the decision, warning that the chemicals may degrade into "forever chemicals" linked to serious health risks. The approvals, covering diflufenican, epyrifenacil, and trifludimoxazin, have opened a sharp dispute over how the federal government defines PFAS and whether the EPA's review standards are keeping pace with the science.
The Center for Biological Diversity and the Center for Food Safety both flagged the approvals as potentially dangerous to Americans' health, the Daily Caller reported. At the center of the disagreement: whether pesticides containing a single fluorinated carbon qualify as PFAS, and whether the EPA's narrower definition gives those chemicals an undeserved pass.
The EPA told the Daily Caller that its definition of PFAS requires two or more fluorinated carbons, a threshold it attributed to the Biden-era Office of Pollution Prevention and Toxics. The agency said that standard was "deliberate, grounded in extensive scientific evidence that single-fluorinated-carbon molecules lack the persistence and bioaccumulation that define genuine PFAS."
The Organization for Economic Cooperation and Development takes a broader view, classifying chemicals with even a single fluorinated carbon as PFAS. So does the National Institute of Environmental Health Sciences, which indicates on its website that a chemical qualifies as PFAS if it has one carbon-fluorine bond.
The EPA pushed back on the OECD standard directly:
"OECD has no regulatory authority on this matter, and OECD itself states its definition 'serves as a starting and reference point' and that 'individual users may define their own working scope of PFASs for specific activities according to their specific needs.'"
That framing gives the EPA room to set its own threshold. But the watchdog groups argue the agency is using that room to sidestep a real hazard.
The Center for Biological Diversity countered the EPA's position bluntly:
"Chemicals with single fully fluorinated carbons can stick around for generations or longer, which was the basis for their inclusion in the widely accepted PFAS definition."
Yale Sustainability has explained that carbon-fluorine bonds are extremely strong, which is what makes forever chemicals so difficult to break down in the environment. That durability is exactly what the watchdog groups say the EPA is underestimating.
The Center for Biological Diversity reported that diflufenican and epyrifenacil will ultimately break down into PFAS chemicals, including trifluoroacetic acid, or TFA. The group warned that most PFAS pesticides are expected to degrade into TFA, which "could linger in the environment at harmful levels anywhere from months to decades depending on the chemical properties of the individual pesticide."
The Center for Food Safety raised a separate alarm about epyrifenacil, reporting that it caused liver tumors in male mice. Meanwhile, the EPA itself has previously found what it described as "suggestive evidence" that trifludimoxazin leads to cancer, though the agency still approved it. The timing and specific basis for that earlier finding were not detailed.
Denmark offers a concrete international comparison. In 2025, Denmark's Environmental Protection Agency pulled authorization for 23 pesticides, including diflufenican, partly over alleged TFA contamination. The Pesticide Action Network reported that action. While the Trump administration has been moving quickly to install its own leadership across federal agencies, the EPA's pesticide approvals now put the United States on the opposite side of a European regulatory decision that went the other direction.
The EPA described its approval process as rigorous. In its statement to the Daily Caller, the agency said its registration decisions applied "the same gold-standard review required for every pesticide," including comprehensive toxicity testing, evaluation of children's safety and developmental effects, reproductive and chronic health assessments, environmental fate analysis, and Endangered Species Act evaluations with mitigation where warranted.
On the specific question of single-fluorinated-carbon compounds, the agency was direct:
"Persistence and bioaccumulation are precisely what [the] EPA's review examines, and they are exactly what single-fluorinated-carbon compounds lack."
The EPA also told Newsweek that all three approved pesticides, diflufenican, epyrifenacil, and trifludimoxazin, consist of single-fluorinated-carbon molecules, which is why the agency does not classify them as PFAS under its own definition.
That distinction is the entire ballgame. If the EPA's threshold is scientifically sound, these approvals are routine. If the OECD and NIEHS are closer to the mark, the EPA may be allowing chemicals with real persistence into the American food and water supply under a convenient definitional carve-out.
Several important details remain unclear. Neither the specific crops these pesticides are authorized for nor the manufacturers who applied for EPA registration were identified. The U.S. Department of Agriculture did not respond to the Daily Caller's request for comment by the time of publication. Whether the Center for Biological Diversity or the Center for Food Safety plan any legal challenge to the approvals is also unknown.
The administration has been exercising executive authority aggressively across multiple agencies this year. In that context, the EPA's pesticide decision is one more front where federal regulators are making consequential calls that will shape policy for years.
None of the quoted statements from the watchdog groups were attributed to named individuals, only to the organizations themselves. That matters because it makes it harder to evaluate the expertise and standing of the people making these claims. The EPA's statements were likewise institutional, not personal.
Congress has been pressing the administration for transparency on data and decision-making in other policy areas. Whether any members take up the pesticide question, particularly lawmakers from major agricultural states, could determine whether these approvals draw sustained scrutiny or fade from view.
Forever chemicals are not an abstraction. PFAS contamination has been linked to a range of health problems, and Americans rightly expect their government to draw the line in the right place when it comes to what ends up in their soil and water. The EPA says it did exactly that. Two well-known environmental groups say the agency rigged the definition to get the answer it wanted.
What makes this dispute worth watching is that it is not a simple left-versus-right fight. Farmers, rural communities, and families who depend on clean groundwater have as much at stake as any advocacy group. The question is whether the EPA's narrower PFAS definition reflects genuine science, or a convenient shortcut that lets chemicals through the gate before the full picture is clear.
With major legislation moving through Congress on other fronts, the pesticide approvals may not command front-page attention for long. But the downstream consequences, literally, will outlast the news cycle. TFA does not care about the definition the EPA chose. It either breaks down or it doesn't.
The EPA told the Daily Caller that the Biden administration's own Office of Pollution Prevention and Toxics set the two-carbon threshold. That means the current EPA inherited a definition it is now defending, and the watchdog groups are, in effect, arguing that both administrations got it wrong.
Denmark pulled diflufenican off the market. The EPA just approved it. One of those decisions will look better with time, and the people who will find out first are the ones drinking the water.
When the government tells you a chemical is safe because it doesn't meet the government's own definition of dangerous, it's worth asking who wrote the definition, and why.
