SCOTUS
Monsanto v. Durnell
DecidedJun 25, 2026
7-2decision
Source: CourtListener.
Federal law blocks state cancer-warning lawsuits against Roundup maker Monsanto
Impact8/10
What it does
FIFRA's "Uniformity" clause bars states from imposing pesticide labeling requirements that are "in addition to or different from" those required under federal law. Because the EPA approved Roundup's label without a cancer warning — and federal law requires Monsanto to use that exact label — a Missouri jury verdict ordering Monsanto to pay damages for not including a cancer warning is preempted. State tort failure-to-warn claims that would effectively require a pesticide label different from the EPA-approved label cannot proceed.
Who benefits
Pesticide manufacturers who sell products with EPA-approved labels, who are now shielded from state tort lawsuits seeking label warnings that the EPA has not required.
Who is affected
People who allege they were harmed by pesticide exposure and seek damages through state courts on the theory that the pesticide's label lacked an adequate warning, who are now barred from bringing those claims.
Practical impact
Thousands of pending state-court lawsuits against Monsanto and other pesticide manufacturers based on failure-to-warn theories are now effectively foreclosed, as long as the manufacturer's label was EPA-approved. People who believe they were harmed by pesticide exposure must instead seek relief through the federal regulatory process — for example, by petitioning the EPA to require new label warnings or to cancel a pesticide's registration — rather than through state tort litigation. Pesticide manufacturers gain significant protection from state jury verdicts as long as they use their EPA-approved labels.
Majority — Kavanaugh
Joined by: Roberts, Thomas, Alito, Sotomayor, Kagan, Barrett
The majority held that FIFRA's preemption clause, titled "Uniformity," prohibits states from imposing any pesticide labeling requirement that is "in addition to or different from" those required under federal law. The Court reasoned that EPA's registration process — which requires the agency to review and approve every pesticide label and to confirm it contains all warnings necessary to protect human health — creates binding federal labeling requirements, not merely advisory guidance. Because EPA has repeatedly concluded that glyphosate is not likely to cause cancer and has approved Roundup's label without a cancer warning, federal law affirmatively requires Monsanto to use that label; a state tort verdict demanding a cancer warning therefore imposes a conflicting, additional requirement. The majority drew a direct parallel to Riegel v. Medtronic, where the Court held that FDA premarket approval of medical devices similarly preempted state tort claims, noting that FIFRA's and the Medical Device Amendments' preemption clauses are nearly identical. The Court also rejected the argument that a separate FIFRA provision — stating that registration is not a "defense" to a federal misbranding charge — undermines preemption, explaining that provision applies only to EPA enforcement actions and does not negate the preemptive force of EPA's specific labeling determinations.
Dissent reasoning
The dissent argued that the majority misidentifies the relevant federal "requirement" under FIFRA. In Justice Jackson's view, FIFRA's primary labeling requirement is its ongoing prohibition on selling "misbranded" pesticides — meaning pesticides whose labels lack warnings that are necessary and adequate to protect health — and Missouri's failure-to-warn tort imposes the exact same standard, making it a parallel (not additional or different) requirement that is not preempted. The dissent emphasized a key statutory provision, §136a(f)(2), which states that EPA registration "shall not be construed as a defense" to a misbranding charge and that registration is only "prima facie" — not conclusive — evidence of label compliance; this, the dissent argued, shows that EPA's label approval cannot itself be a binding legal requirement, since a registered pesticide can still be misbranded. The dissent also distinguished Riegel v. Medtronic on the ground that the Medical Device Amendments contain no equivalent to FIFRA's §136a(f)(2), and that Riegel did not involve parallel state and federal claims. Finally, the dissent argued that the Court's own prior ruling in Bates v. Dow Agrosciences — the only prior case interpreting FIFRA's preemption clause — necessarily rejected the majority's theory, because Bates remanded a failure-to-warn case for further proceedings rather than declaring all such claims preempted by EPA label approval.
Constitutional question
Does the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) expressly preempt a state-law failure-to-warn lawsuit seeking to require a cancer warning on Roundup's label, when the EPA has repeatedly approved Roundup's label without such a warning?
Precedent changed
Bates v. Dow Agrosciences LLC (2005) narrowed: the majority limits Bates's allowance of parallel state tort claims to efficacy-related claims (which EPA does not review at registration), holding that safety-related failure-to-warn claims — which EPA does review — are preempted by EPA's registration determinations.