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Supreme Court decisions
No. 24-1068Jun 25, 2026Environmental ProtectionReversed

The question

Whether FIFRA preempts a state-law failure-to-warn claim that would require a pesticide manufacturer to add a cancer warning to a label the EPA approved.

Monsanto v. Durnell

What the Court decided

The Court reversed the judgment against Monsanto and held that FIFRA preempts Durnell's state-law failure-to-warn claim. Because federal law requires Monsanto to sell Roundup with the label the EPA approved, and the EPA did not require a cancer warning, a state-law duty to add a cancer warning would impose a labeling requirement different from the federal one. FIFRA's uniformity clause bars states from imposing labeling requirements in addition to or different from those required under the federal statute.

How the justices split

7-2
In favor 7Against 2
Kavanaugh
Roberts
Thomas
Alito
Sotomayor
Kagan
Barrett
Jackson
Gorsuch

The Court's opinion

Kavanaugh, joined by Roberts, Thomas, Alito, Sotomayor, Kagan, Barrett

FIFRA's uniformity clause bars a state from imposing labeling requirements in addition to or different from those required under federal law. The EPA approves a pesticide's label at registration and manufacturers must use that label unless and until the EPA approves or requires a change. Because the EPA approved Roundup's label without a cancer warning, a state failure-to-warn claim that would require adding one imposes a different labeling requirement and is preempted.

Concurring

Thomas, writing alone

Thomas joined the opinion of the Court in full and wrote separately to state additional views.

Dissenting

Jackson, joined by Gorsuch

Jackson would not have held Durnell's state-law failure-to-warn claim preempted by FIFRA.

How we know · 5 sourced claims
  • The Court held that FIFRA expressly preempts Durnell's state-law failure-to-warn claim because it would require Monsanto to add a cancer warning to Roundup's label.

    Source: syllabus, Held

  • FIFRA's uniformity clause provides that a state shall not impose or continue in effect any labeling or packaging requirements in addition to or different from those required under the federal statute.

    Source: syllabus, Held

  • The EPA had not required a cancer warning on glyphosate-based pesticides like Roundup, having concluded that glyphosate is not likely to cause cancer.

    Source: syllabus, Held

  • Kavanaugh delivered the opinion of the Court, joined by Roberts, Thomas, Alito, Sotomayor, Kagan, and Barrett.

    Source: syllabus, lineup

  • Jackson filed a dissenting opinion, joined by Gorsuch.

    Source: syllabus, lineup

Read the opinion on supremecourt.gov