Background
John Durnell sued Monsanto in Missouri state court, alleging that roughly twenty years of exposure to Roundup — Monsanto’s glyphosate-based herbicide — caused his non-Hodgkin’s lymphoma. His central claim was a state-law failure-to-warn tort: Monsanto, he argued, should have placed a cancer warning on Roundup’s label. A jury awarded him more than $1 million, and the Missouri Court of Appeals affirmed, reasoning that Missouri’s failure-to-warn duty was “fully consistent with” FIFRA because both regimes require manufacturers to adequately warn of dangers.
The case arose against a background of sharply divided lower courts. Several federal circuits and state appellate courts had ruled that FIFRA does not preempt glyphosate failure-to-warn claims — including the Ninth Circuit in Hardeman, the Eleventh Circuit in Carson, and California and Oregon appellate courts — while the Third Circuit reached the opposite conclusion in Schaffner. The Supreme Court granted certiorari to resolve the split.
The Environmental Protection Agency first registered glyphosate-based pesticides in 1974 and has repeatedly re-evaluated glyphosate since 1991, concluding on each occasion that it is not likely to cause cancer in humans. That assessment is shared by regulators in Canada, Australia, Japan, and the European Union. Consistent with those determinations, EPA has never required a cancer warning on Roundup’s label, and federal regulations affirmatively require Monsanto to use the EPA-approved label unless and until EPA approves or mandates a change.
The Court’s Holding
In a 7–2 decision authored by Justice Kavanaugh, the Court reversed and remanded, holding that FIFRA’s preemption clause expressly bars Durnell’s state-law failure-to-warn claim. FIFRA’s “Uniformity” provision, 7 U.S.C. § 136v(b), prohibits states from imposing “any requirements for labeling or packaging in addition to or different from those required under” FIFRA. Because Durnell’s tort claim would compel Monsanto to add a cancer warning to Roundup’s label — a label that EPA has approved and re-approved multiple times without any such warning, and that Monsanto is legally obligated to use — the claim imposes a labeling requirement that is both “in addition to” and “different from” the federal requirement.
The Court held that state tort duties qualify as state labeling requirements under FIFRA’s preemption clause, consistent with prior precedent in Bates v. Dow Agrosciences and Riegel v. Medtronic. EPA’s registration and label-approval process embodies the agency’s considered judgment that the approved label is neither false nor misleading and includes all warnings necessary to protect human health. That regulatory determination — not merely the statutory text itself — constitutes a “requirement” imposed “under” FIFRA, and therefore carries preemptive force. The analogy to Riegel, where FDA premarket approval of medical devices preempted state tort suits under a materially identical preemption clause, was held to be directly on point.
The Court rejected each of Durnell’s counterarguments. It dismissed the contention that Missouri’s tort duty merely parallels FIFRA’s general mandate to avoid false or misleading labels, finding that argument operated at an impermissibly high level of generality that ignored EPA’s specific, affirmative determination that no cancer warning was required. The Court also rejected the argument that EPA’s registration procedures exceeded FIFRA’s statutory grant of authority, and held that the statutory provision stating that registration shall not be “construed as a defense for the commission of any offense under FIFRA,” 7 U.S.C. § 136a(f)(2), does not apply to state tort suits and does not disturb the preemption analysis.
Key Takeaways
- State-law failure-to-warn tort claims targeting EPA-approved pesticide labels are expressly preempted by FIFRA’s Uniformity clause, 7 U.S.C. § 136v(b), when they would require warnings that EPA has specifically declined to mandate.
- EPA’s affirmative determination at registration that a pesticide’s label is adequate — including its decision not to require a cancer warning — constitutes a binding federal “requirement” with preemptive effect, not merely permissive approval.
- The decision abrogates several prominent circuit and state-court rulings, including the Ninth Circuit’s Hardeman v. Monsanto, the Eleventh Circuit’s Carson v. Monsanto, and state-court decisions in California (Pilliod) and Oregon (Johnson), effectively extinguishing a broad category of Roundup litigation that had produced massive jury verdicts against Monsanto.
- Justice Jackson, joined by Justice Gorsuch, dissented.
Why It Matters
This decision resolves one of the most consequential and long-running product-liability disputes in American tort law, ending the theory of liability that had generated billions of dollars in verdicts and settlements against Monsanto and its parent Bayer AG. By holding that EPA’s registration determinations carry preemptive force over state failure-to-warn claims, the Court substantially insulates pesticide manufacturers from state-court liability as long as they use their EPA-approved labels — even when plaintiffs contend those labels are inadequate to warn of health risks.
More broadly, the ruling reinforces the framework established in Riegel v. Medtronic for agency-approved products: when a federal agency with comprehensive regulatory authority makes an affirmative determination about a product’s labeling, that determination can foreclose state tort remedies that would impose conflicting requirements. Plaintiffs who believe EPA’s glyphosate assessments are wrong must now seek redress through the agency’s regulatory process, or through Congress — not through state-court juries.