EPA’s New Herbicide Proposal Rekindles “Forever Chemicals” Fight — and Sets Up a Red-State/Blue-State Policy Clash
On November 3, the Environmental Protection Agency opened a 30‑day public comment period on the proposed registration of epyrifenacil, a pre‑plant “burndown” herbicide for corn, soy, wheat, canola and non‑crop areas. The move comes as environmental and industry groups clash over how the U.S. should regulate PFAS — the broad class of “forever chemicals” that includes many fluorinated pesticides — and just days after new reporting highlighted pressure inside the Trump administration to greenlight additional PFAS‑related pesticide uses. [1]
- What’s new: EPA proposed registering epyrifenacil; public comments close December 3, 2025. [2]
- Why it matters: Epyrifenacil contains a fluorinated carbon, pulling it into the definitional tug‑of‑war over what counts as PFAS — a fight that shapes how aggressively the U.S. regulates entire subclasses of chemicals. [3]
- What’s disputed: Environmental advocates warn some fluorinated pesticides can degrade into trifluoroacetic acid (TFA), an ultra‑short‑chain PFAS now under proposed EU classification as reprotoxic; EPA says each pesticide is assessed case‑by‑case under FIFRA. [4]
The proposal: scope, safeguards, and timeline
EPA’s proposal would allow two products with the new active ingredient epyrifenacil for pre‑plant burndown uses in canola, field corn, soybeans, wheat and fallow land, plus non‑agricultural applications near industrial and farm buildings. The agency says its human‑health assessment identified “no risks of concern” when used according to label, but its Endangered Species Act screening found the use “may affect and [is] likely to adversely affect” multiple listed species — prompting added mitigation: drift buffers, runoff/erosion controls, rain/saturation restrictions, and compliance with ESA bulletins. EPA set a 30‑day comment window through December 3, 2025, under docket EPA‑HQ‑OPP‑2022‑0354. [5]
The policy fault line: what counts as PFAS — and why it matters
At the heart of the political fight is definition. The OECD’s widely cited 2021 guidance defines PFAS as any fluorinated substance with at least one fully fluorinated methyl or methylene carbon (e.g., –CF3 or –CF2–). By that standard, many fluorinated pesticides fall inside the PFAS universe, despite differing toxicity profiles. U.S. agencies and states reference varying definitions, affecting surveillance, reporting, cleanup liability, and whether to regulate PFAS as a class or one‑by‑one. [7]
Scientists have warned against efforts to narrow the PFAS definition, arguing it would create regulatory blind spots. European and U.S. media coverage this year documented lobbying to exclude whole sub‑families, even as utilities and public‑health groups push for broader controls. [8]
Europe’s signal on TFA raises stakes for fluorinated pesticides
European authorities have moved to classify trifluoroacetic acid (TFA) — an ultra‑short‑chain PFAS and a breakdown product of several fluorinated chemicals — as toxic to reproduction (Category 1B) and “very persistent, very mobile” in the environment. Germany submitted the harmonized classification dossier to ECHA this spring; the Risk Assessment Committee opinion is pending. The German Environment Agency notes TFA has been detected widely in groundwater and is difficult to remove with standard treatment. [9]
U.S. context is mixed: EPA’s HERO database includes literature that historically characterized environmental risks from TFA as low at expected ambient levels, but that analysis pre‑dates recent European hazard proposals and broader detection. Translation: the science and policy signals are diverging across the Atlantic, complicating U.S. risk communication. [10]
EPA’s pesticide stance
EPA says any pesticide — PFAS or not — must pass a chemical‑specific safety review, and it has proposed PFAS reporting and limits in multiple programs (TRI additions, TSCA reporting). [11]
Advocates’ demand
Environmental and water groups increasingly urge PFAS “class‑based” control, citing mobility, persistence and cumulative load in drinking water sources. [12]
Today’s flashpoint
The Guardian reported today that the administration is poised to approve another PFAS‑linked pesticide ingredient, spotlighting how EPA treats fluorinated actives such as epyrifenacil. EPA’s Nov. 3 notice does not itself identify TFA as a metabolite; the docketed risk assessments will be central to this debate. [13]
How we got here: U.S. PFAS policy signals in 2024–2025
- EPA expanded PFAS tracking in the Toxics Release Inventory and advanced TSCA reporting rules for PFAS manufactured or imported since 2011, while moving separate drinking‑water policy and Superfund actions for legacy PFAS like PFOA/PFOS. [14]
- The agency has also framed a communications stance: pesticides with “a fluorinated carbon” undergo the same risk‑based FIFRA review as other actives; that position diverges from advocates urging categorical restrictions on fluorinated pesticides. [15]
- Earlier reporting this year described an EPA plan to roll back parts of Biden‑era PFAS drinking‑water limits while maintaining the strictest two, a move environmental groups vowed to fight; a final rulemaking would determine legal durability. [16]
What each side is arguing
| EPA/Industry View | Environmental/Water Utilities View |
|---|---|
| - FIFRA already requires chemical‑specific risk determinations; epyrifenacil shows no human‑health risks of concern at labeled uses, and EPA can impose mitigation to reduce ecological exposure. - “PFAS” is too broad; some fluorinated molecules may not pose the same risks as legacy PFAS. [17] | - Fluorinated actives and some inerts can degrade into persistent PFAS like TFA that move rapidly through watersheds and evade conventional treatment; precaution should guide approvals. - EU’s proposed TFA classification underscores long‑term hazards U.S. policy is downplaying. [18] |
Expert context: what science can (and can’t) say now
Peer‑reviewed work shows some fluorochemicals can biodegrade to TFA; detection is rising, but translating environmental concentrations into population‑level health risk remains contested and region‑specific. Expect the epyrifenacil docket’s environmental‑fate data to draw intense scrutiny over whether its use contributes meaningfully to TFA loads. [19]
“Harmonised classification is an important tool for communicating hazards and forms the basis for risk management… we are laying an important foundation for reducing inputs of this persistent and hazardous chemical.” — German Federal Office for Chemicals on its TFA dossier to ECHA (May 26, 2025). [20]
What to watch next (November–December 2025) 🗓️
EPA’s docketed science
Look for metabolism and fate studies in EPA‑HQ‑OPP‑2022‑0354 to clarify whether epyrifenacil yields TFA or other persistent products under real‑world conditions. Public comments due December 3. [21]
Definition politics
If the administration narrows the working definition of PFAS in any program, litigation is likely; scientists and EU regulators are moving the other way. [22]
Water‑sector pushback
Utilities facing costly treatment upgrades will press EPA to evaluate PFAS‑generating pesticides cumulatively — not molecule‑by‑molecule — in light of TRI expansions and pending TSCA reporting. [23]
Bottom line
EPA’s epyrifenacil proposal is more than a routine label action: it’s a bellwether for how the U.S. will reconcile a risk‑by‑risk pesticide law with growing pressure — here and abroad — to treat PFAS as a class. The agency argues its existing toolbox can manage risks using targeted mitigation and case‑specific science. Environmental advocates counter that persistent, mobile PFAS like TFA demand upstream prevention, not down‑stream cleanup. The next month of comments — and the technical record EPA releases — will signal which philosophy is prevailing. [24]
How to weigh in
References
- EPA: “EPA Announces Proposed Registration of Herbicide Epyrifenacil” (Nov. 3–4, 2025). [26]
- Guardian: “Trump officials set to approve ‘forever chemical’ as pesticide ingredient” (Nov. 11, 2025). [27]
- EPA: “Pesticides Containing a Fluorinated Carbon” explainer. [28]
- OECD: “Reconciling Terminology… PFAS” (2021) and technical summaries of the definition. [29]
- ECHA/DE authorities: CLH intention and German agencies’ press note on TFA hazard proposal (May 2025). [30]
- EPA HERO: legacy environmental‑risk discussion on TFA. [31]
- EPA TRI PFAS additions (guidance for 2025 reporting). [32]
- AP coverage of U.S. drinking‑water PFAS policy changes (June 2025). [33]
Note on verification: Today’s Guardian report links epyrifenacil to TFA formation; EPA’s Nov. 3 notice does not specify TFA among metabolites in its summary. Readers should examine the full risk assessments in docket EPA‑HQ‑OPP‑2022‑0354 as they are posted; this piece will be updated as the technical record is released. [34]
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