EPA Approves Fifth PFAS-Linked Pesticide; Lawsuit Challenges Its Registration
Updated
The Environmental Working Group is bringing attention to three new fluorinated herbicides that were approved by the Trump administration’s EPA in June 2026. They are trifludimoxazin, diflufenican, and epyrifenacil, and they are approved to be used on U.S. food crops including wheat, oats, corn, soybeans, citrus, and other fruits and nuts. EWG reports that the administration has now approved a total of five “PFAS-linked” pesticides since taking office less than two years ago.
Jared Hayes, senior policy analyst at EWG, said the approval of new PFAS pesticides is contrary to the administration’s Make America Healthy Again (MAHA) agenda. “Contaminating our agricultural fields with persistent forever chemicals does nothing to help the farmers who work tirelessly to feed us,” Hayes said. “By prioritizing corporate chemical approvals over public health, the EPA is actively undermining both our long-term food security and the very farming communities we rely on.”
Trifludimoxazin, a BASF product cleared for cereals, citrus, fruits, nuts, soybeans, and peanuts, has been classified by the EPA as having “suggestive evidence of carcinogenic potential” because of tumors in animal studies. The EPA reviewed animal studies that also suggest possible neurological defects, reproductive harm, and birth defects, but the EPA said the concern about these is low based on the data.
The Center for Food Safety, the Center for Biological Diversity, and Pesticide Action & Agroecology Network North America announced a lawsuit against the Trump EPA on August 31 for the registration of Trifludimoxazin.
“As if the health threats weren’t enough, this incredibly potent herbicide can drift to stunt crops and wild plants hundreds of yards from a sprayed field, while runoff threatens wetland plants. Potent biocides like this have no business on the American landscape,” said Bill Freese, science director at Center for Food Safety.
The EPA says that despite its classification, there are no human health risks associated with the chemical when used according to the label.
The Center for Biological Diversity and the Center for Food Safety first sued BASF in July 2021 after the Biden administration approved the chemical a month earlier. CFS conducted an analysis that found the chemical is 10 times more potent than dicamba and cited that in its lawsuit. BASF agreed to stop manufacturing Trifludimoxazin in February 2022 and filed a request to voluntarily cancel the registrations. The lawsuit was withdrawn and BASF resubmitted a new registration application two months later in April 2022.
The Trump EPA proposed a registration decision in June 2025 and officially approved the registration a year later in June 2026.
The EPA has several high-ranking officials in the pesticide and chemical safety offices with documented ties to the chemical and pesticide industry. Kyle Kunkler spent years as a top lobbyist for the American Soybean Association advocating for the continued use of pesticides, including dicamba. Kukler became deputy assistant administrator for pesticides in mid-2025. Nancy Beck, a former American Chemistry Council executive, is a deputy assistant administrator; Lynn Dekleva, who worked for DuPont and the Chemistry Council for decades, is a deputy assistant administrator in the Office of Chemical Safety and Pollution Prevention.
The HighWire has reported previously about a meeting between EPA officials and Bayer executives in June 2025. All three of the EPA officials were connected with the agrochemical industry before working with the Trump administration. Following the meeting, the administration filed a Supreme Court brief supporting Bayer that has granted a degree of immunity from lawsuits for pesticide manufacturers. The administration has also approved Dicamba and President Trump signed an executive order declaring glyphosate production as a national security priority.
Along with trifludimoxazin, EWG and other organizations label diflufenican and epyrifenacil as “forever chemical” pesticides under broader scientific definitions of per- and polyfluoroalkyl substances (PFAS) as chemicals that contain at least one fully fluorinated carbon atom. PFAS is classically defined by nearly unbreakable carbon-fluorine bonds and has been linked to immune system suppression, reproductive and developmental harm, hormone disruption, certain cancers, and reduced vaccine effectiveness at very low exposures.
Trifludimoxazin has 12 persistent fluorinated degradates according to statements by environmental groups, while Bayer’s Diflufenican contains a trifluoromethyl group known to degrade into trifluoroacetic acid (TFA), an ultra-short-chain PFAS that is highly persistent, mobile, and accumulating in groundwater, soil, and people worldwide. Epyrifenacil has produced liver tumors in male mice, but the EPA classifies the chemical as “not likely to be carcinogenic to humans below doses that induce hepatocellular injury.”
However, none of these chemicals are classified as PFAS or “forever chemicals” based upon the EPA definition that was modified in 2023 by the Office of Pollution Prevention and Toxics under the Biden administration. The definition of PFAS is “chemicals containing two or more fluorinated carbons.”
An EPA fact check published in November 2025 states, “This deliberate exclusion of single fluorinated carbons was based on extensive scientific evidence and public input demonstrating that molecules with only one fluorinated carbon lack the persistence and bioaccumulation properties that are commonly associated with forever chemicals. The recent false claims that EPA approved a “forever chemical” represent a fundamental misunderstanding of chemistry and toxicology.”
That definition still conflicts with the 2021 definition given by the Organization for Economic Co-operation and Development (OECD), an intergovernmental organization of 38 mostly high-income member countries.
A 2026 study published in the Journal of Environmental Quality tested seven common trifluoromethyl pesticides in agricultural soils and detected trifluoroacetic acid (TFA), a degradation product of CF3 pesticides that is widely detected in the environment. EPA critics cite the lack of research on other degradates from these chemical products that may not break down naturally in the environment.
In November 2025, EPA Administrator Lee Zeldin also called reports of the administration approving PFAS pesticides as “fake news” and said “sound, gold standard science is what drives ALL of these reviews.”