On June 25, 2026, the U.S. Supreme Court issued a significant decision affecting pesticide manufacturers and product liability litigation nationwide, ruling 7-2 that the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) preempts state-law failure-to-warn claims that challenge EPA-approved pesticide labels. The decision, authored by Justice Kavanaugh, resolves a circuit split and is expected to significantly curtail the tens of thousands of pending Roundup lawsuits brought against Monsanto.

The case arose from a lawsuit filed by John Durnell, a Missouri gardener, who used Roundup, a glyphosate-based herbicide, for more than two decades before developing non-Hodgkin’s lymphoma. Durnell alleged that Monsanto failed to warn users of Roundup’s potential cancer risk, and a Missouri jury awarded him more than $1 million in damages. The Missouri Court of Appeals affirmed, reasoning that state failure-to-warn duties were consistent with FIFRA’s misbranding provisions. Monsanto appealed, arguing that FIFRA’s express preemption clause bars any state-law requirement “in addition to or different from” federal labeling requirements, and that the EPA had repeatedly evaluated glyphosate and concluded it is not likely to cause cancer, and accordingly had not required a cancer warning on Roundup’s label.

The Supreme Court agreed with Monsanto. The Court held that a state-law failure-to-warn claim functions as a state labeling requirement, and that because EPA has reviewed the relevant carcinogenicity evidence and declined to require a cancer warning, a state jury verdict imposing liability for the absence of such a warning would impose a requirement different from the one EPA approved. The Court rejected the argument that state and federal law share the same underlying goal of ensuring adequate warnings, finding that reasoning too general and dismissive of the EPA’s central role in making labeling determinations. Justice Jackson, joined by Justice Gorsuch, dissented, arguing that the majority’s decision rests on a labeling requirement that does not exist and leaves Durnell, along with similarly situated plaintiffs, without a remedy.

The ruling is expected to resolve the bulk of the roughly 100,000 pending Roundup-related lawsuits nationwide, though it does not foreclose all avenues for plaintiffs. Claims not predicated on labeling, such as design defect, manufacturing defect, and advertising or promotional claims, as well as claims involving risks EPA has not affirmatively considered, may remain viable. The decision also carries broader implications for other FIFRA-regulated manufacturers and may influence preemption analysis in other federally regulated industries, such as pharmaceuticals and medical devices, where similar disputes over the interplay between agency approval and state tort law persist. Additional litigation, including challenges related to Monsanto’s proposed multibillion-dollar settlement of remaining Roundup claims, remains ongoing.