On June 25, 2026, the U.S. Supreme Court issued its decision in Monsanto Co. v. Durnell, resolving a dispute over the scope of federal preemption under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), 7 U.S.C. Section 136 et seq. The case presented the question of whether FIFRA preempts a label-based state-law failure-to-warn claim where the U.S. Environmental Protection Agency (EPA) has approved a label that does not require the warning at issue. In a 7-2 decision, the Court held that FIFRA expressly preempts plaintiff’s state-law failure-to-warn claim because it would require Monsanto to add a cancer warning to Roundup’s label.
The decision resolves a circuit split, holding that federal pesticide labels preempt divergent or additional state warning or labeling requirements. It may limit state-law claims against pesticide registrants based on theories of inadequate warning and may provide guidance for pesticide registrants, manufacturers of federally regulated products, and litigants navigating the intersection of federal labeling approvals and state tort law.
Background on FIFRA
FIFRA establishes the federal framework governing the registration, sale, distribution, and labeling of pesticides. Under that framework, the EPA reviews pesticide labels and may approve a product only if, among other things, its labeling is not false or misleading and the product will not cause unreasonable adverse effects on human health and the environment when used in accordance with commonly recognized practice. FIFRA also contains an express preemption provision, entitled “Uniformity,” which bars states from imposing any “requirements for labeling or packaging in addition to or different from those required under” FIFRA. 7 U.S.C. Section 136v(b).
Procedural History of Durnell
The dispute arose from claims involving Roundup, a glyphosate-based herbicide. In January 2019, plaintiff John L. Durnell alleged in Missouri state court that exposure to Roundup caused non-Hodgkin lymphoma and asserted Missouri state-law claims, including strict liability failure to warn.
A jury ruled in Durnell’s favor on the failure-to-warn theory but rejected his defective-design and negligence claims. Monsanto sought judgment notwithstanding the verdict, arguing that FIFRA preempted a warning theory based on a cancer warning the EPA had not required. The trial court denied the motion. The Missouri Court of Appeals affirmed, and the Supreme Court granted certiorari to decide whether FIFRA preempts a label-based failure-to-warn claim where EPA has not required the warning at issue.
The Court granted certiorari to resolve a circuit split: the Ninth and Eleventh Circuits had allowed state failure-to-warn claims that would require label changes, while the Third Circuit had found such claims preempted. The case came to the Court against the backdrop of Bates v. Dow Agrosciences LLC, 544 U.S. 431 (2005), which held that FIFRA does not preempt state-law claims imposing requirements equivalent to, and fully consistent with, FIFRA but does preempt state-law labeling or packaging requirements that add to or differ from federal requirements.
The Supreme Court’s Decision
The Supreme Court’s decision clarified how FIFRA’s express preemption clause applies when a plaintiff seeks to impose liability for the absence of a warning the EPA has not required. In the Court’s view, a state tort duty can function as a labeling “requirement” for purposes of FIFRA preemption. The Court’s analysis focused on whether the state-law duty would operate as a genuinely parallel requirement under Bates or instead compel a registrant to provide labeling “in addition to or different from” that required under FIFRA, 7 U.S.C. Section 136v(b). Because the state-law duty would have required a warning different from the federally approved label, it was barred.
The majority1 emphasized that EPA’s registration process requires the agency to determine whether a pesticide label contains adequate warnings and avoids false or misleading statements. The Court treated EPA’s approval and repeated re-approval of Roundup labels without a cancer warning as federal labeling requirements under FIFRA. It rejected the argument that Durnell’s claim merely paralleled FIFRA’s misbranding standard, which prohibits “false and misleading” statements or the omission of any statement “necessary and . . . adequate to protect health and the environment,” reasoning that the practical effect of the claim was to impose a warning the EPA had not required. The Court cited Bates, Riegel v. Medtronic, Inc., 552 U.S. 312 (2008), and Cipollone v. Liggett Group, Inc. 505 U.S. 504 (1992), for the proposition that state tort duties constitute state labeling requirements.
The Court viewed Riegel as confirmation of its holding, noting that the preemption clause in the Medical Device Amendments of 1976 is nearly identical to FIFRA’s preemption clause, and that the “Riegel Court concluded that FDA’s premarket approval of devices imposed ‘‘requirements’ under” the Act’s preemption clause, 552 U. S., at 322, and therefore that FDA’s premarket approval of a medical device preempted state-law claims premised on additional or contrary safety requirements.”
In distinguishing its decision in Bates, the Court recognized the difference between efficacy and safety claims, noting that safety claims undergo EPA’s registration review, and held that safety-related failure-to-warn claims that would impose labeling requirements “in addition to” or “different from” those required under FIFRA are preempted. While Bates was not overruled, Durnell appears to supersede it as the principal precedent in this area.
The Court also rejected Durnell’s (and the dissent’s) argument that a separate provision (Section 136a(f)(2)) stating that registration is not a defense to a misbranding charge means that a properly registered pesticide can nonetheless be misbranded under state tort law. The Court reasoned that the provision, by its terms, does not apply to state tort suits and merely clarifies that registration does not bar EPA enforcement and that the EPA would not bring an enforcement action for misbranding when a manufacturer is using an EPA-approved and required label. The Court further stated it would be anomalous to read the provision to “negate FIFRA’s express preemption clause, expose manufacturers to potentially massive tort liability for doing what EPA required them to do, and eviscerate the ‘uniformity’ of EPA’s labeling determinations.”
Justice Ketanji Brown Jackson, joined by Justice Neil Gorsuch, dissented. The dissent argued that Durnell’s claim was not preempted because it paralleled FIFRA’s prohibition on misbranded pesticides rather than imposing an additional or different requirement. In the dissent’s view, citing the provision that registration does not create a defense to a misbranding charge because EPA registration and label approval do not themselves create preemptive federal requirements displacing state-law claims. The dissent also argued that Bates permits state-law claims that enforce requirements equivalent to the federal misbranding standard, which the EPA has not fleshed out through regulations.
Why It Matters
The Durnell ruling is relevant to pesticide registrants, the EPA, state pesticide regulators, those following product liability litigation, and those tracking federal preemption in regulated industries. For manufacturers, the decision may foreclose a pathway for failure-to-warn claims where an EPA-approved label did not require the warning at issue. More broadly, the decision reinforces national uniformity in areas subject to federal labeling requirements.
The decision confirms that, where the EPA has approved a pesticide label that does not include a specific warning (even where that was considered), FIFRA bars state-law failure-to-warn claims seeking to require it. In doing so, the decision narrows the role of state tort law in challenging EPA-approved labeling.
1 Justice Thomas joined the Court’s judgment but wrote separately to reiterate a range of Constitutional concerns he has raised in prior cases. His concurrence questioned the scope of Congress’s authority under the Commerce Clause, the degree of discretion delegated to EPA, and the extent to which federal agency action may preempt state law under the Supremacy Clause. Those issues were not necessary to the Court’s disposition, but the concurrence signals continuing skepticism about the constitutional foundations of broad federal regulatory schemes and the administrative state itself.