Ninth Circuit: EPA Trifludimoxazin Approval Lawsuit Challenges Pesticide

• Environmental groups, including the Center for Biological Diversity, have sued the EPA in the Ninth Circuit over its approval of the pesticide trifludimoxazin.
• The lawsuit challenges the EPA's June registration of trifludimoxazin, which is used on crops like corn, wheat, and almonds, alleging it is harmful to native plants and potentially carcinogenic.
• A key dispute centers on whether trifludimoxazin is a "forever chemical" (PFAS), with advocacy groups asserting it is, while the EPA's definition excludes it due to its single-fluorinated-carbon structure.
• The EPA acknowledged adverse thyroid and liver effects in rats from trifludimoxazin exposure but concluded no short-term health risks and no immediate need for further data.
• The plaintiffs seek to have the court set aside the EPA's registration, which would make the pesticide illegal to use or sell in the U.S.

A judicial ruling that either supports or rejects the EPA's narrow definition of PFAS could influence future regulatory approaches to a wide range of chemicals.

Environmental advocacy organizations have initiated a legal challenge against the U.S. Environmental Protection Agency (EPA) following its decision to register trifludimoxazin, a pesticide that opponents label a "forever chemical." The Center for Biological Diversity, alongside the Center for Food Safety and Pesticide Action & Agroecology Network North America, filed a petition for review in the Ninth Circuit earlier this summer. This Ninth Circuit trifludimoxazin challenge seeks to overturn the EPA's June registration of the substance, arguing it poses significant risks to both human health and the environment.

The EPA trifludimoxazin approval lawsuit specifically targets the agency's authorization for the pesticide's use on a wide array of agricultural products. Trifludimoxazin is currently employed to manage broadleaf and grass weed species across various crops, including corn, wheat, oats, soybeans, oranges, apples, peanuts, and almonds. There are six distinct products containing trifludimoxazin that have received approval for agricultural application. The Center for Biological Diversity EPA suit and its co-plaintiffs contend that the EPA's assessment of this chemical was insufficient and overlooked critical dangers.

The groups assert that trifludimoxazin is not only harmful to native plant life but also carries a potential for carcinogenicity. They highlight concerns that this herbicide, described as a potent biocide, can drift considerable distances—hundreds of yards—from sprayed fields, potentially stunting both cultivated crops and wild vegetation. Furthermore, runoff from treated areas is believed to threaten wetland plants, underscoring the broad environmental impact alleged by the plaintiffs in this EPA 'forever chemical' pesticide lawsuit.

A central point of contention in the litigation revolves around the classification of trifludimoxazin as a perfluoroalkyl and polyfluoroalkyl substance (PFAS), commonly known as a "forever chemical." The advocacy groups firmly categorize trifludimoxazin as a PFAS, citing its chemical structure and potential for persistence. However, the EPA disputes this characterization, asserting that trifludimoxazin does not meet the criteria of the current PFAS definition established by the Biden administration. The agency explains that its definition deliberately excludes single-fluorinated-carbon molecules, like trifludimoxazin, because such substances typically lack the concerning traits of toxicity or bioaccumulation associated with other PFAS compounds.

Despite the EPA's stance, other authoritative bodies, such as the Organisation for Economic Co-operation and Development (OECD), utilize a broader definition of PFAS that would encompass trifludimoxazin. The plaintiffs in the trifludimoxazin PFAS definition dispute rely on this wider international standard, arguing that the EPA's narrow interpretation is flawed. Bill Freese, science director at the Center for Food Safety, has publicly stated that while trifludimoxazin might not fit the EPA's specific definition, the OECD's criteria are widely accepted.

Beyond the definitional debate, the groups raise serious health concerns. Freese has characterized trifludimoxazin as a likely human carcinogen, pointing to animal studies that suggest it can cause reproductive harm, birth defects, and neurological deficits. While the EPA's own memorandum approving trifludimoxazin acknowledged that exposure led to adverse thyroid and liver effects in rats, the agency concluded at the time that no further data was immediately required. The EPA also stated that there are currently no short-term health risks associated with the pesticide. Freese, however, argues that the EPA downplays these findings, contending that the agency should have labeled the chemical as "likely carcinogenic to humans" rather than merely indicating "suggestive evidence of carcinogenic potential."

The advocacy groups are petitioning the Ninth Circuit to set aside the EPA's registration of trifludimoxazin. Should the court grant this request, it would effectively cancel all approved uses of the pesticide, rendering its sale and application illegal throughout the United States. This outcome would have significant ramifications for agricultural practices relying on the six currently registered products containing the chemical. The ongoing pesticide registration litigation US highlights the critical role of judicial review in challenging regulatory decisions concerning chemical approvals.

The broader implications of this case extend beyond trifludimoxazin itself, particularly concerning the trifludimoxazin PFAS definition dispute. A judicial ruling that either supports or rejects the EPA's narrow definition of PFAS could influence future regulatory approaches to a wide range of chemicals. It underscores the ongoing debate about how "forever chemicals" are identified and regulated, potentially impacting chemical manufacturers and agricultural stakeholders. The EPA maintains that its product registrations follow a "robust review" process, ensuring that approved substances do not cause "unreasonable adverse effects on human health or the environment." However, critics argue that the agency's approval process for such chemicals often appears to be a "foregone conclusion," suggesting a lack of objective assessment.

Lawyers advising clients in the agricultural or chemical manufacturing sectors should monitor this Ninth Circuit litigation, as a successful challenge could lead to the ban of trifludimoxazin, impacting product use, supply chains, and environmental compliance obligations. This case also highlights the ongoing regulatory uncertainty and definitional disputes surrounding PFAS substances, which could affect broader chemical regulations.

Source: Original reporting via Courthouse News