Monsanto Co. v. Durnell | Case No. 24-1068 | Docket Link: Here | Argued: April 27, 2026 | Decided: June 25, 2026

Overview: Federal pesticide law blocks a Missouri cancer patient's failure-to-warn lawsuit against Monsanto after the EPA repeatedly approved Roundup's label without requiring a cancer warning, despite the patient's claims linking Roundup to his non-Hodgkin's lymphoma.

Question Presented: Whether the Federal Insecticide, Fungicide, and Rodenticide Act expressly preempts a state-law failure-to-warn claim seeking a cancer warning the EPA declined to require.

Posture: Missouri jury awarded Durnell $1.25M; Court of Appeals affirmed; Supreme Court reversed and remanded.

Main Arguments:

• Monsanto (Petitioner): (1) EPA's registration and label approval without a cancer warning creates a binding federal requirement that preempts stricter state demands; (2) Riegel v. Medtronic establishes that analogous agency approval processes create preemptive federal requirements; (3) Missouri's failure-to-warn verdict retroactively penalizes Monsanto for complying with the federal label EPA mandated.

• Durnell (Respondent): (1) FIFRA's misbranding prohibition — not EPA's specific label approval — sets the operative federal labeling requirement, and Missouri's tort mirrors it exactly; (2) FIFRA § 136a(f)(2) bars treating registration as a complete defense, stripping EPA approval of conclusive force; (3) Manufacturers can add a cancer warning through amended registration or minor modification, defeating impossibility preemption.

Holding: FIFRA's preemption clause, 7 U.S.C. § 136v(b), expressly preempts Durnell's state-law failure-to-warn claim because the claim would require Monsanto to add a cancer warning to Roundup's label in addition to or different from the label required under FIFRA. Reversed and remanded.

Voting Breakdown: 7-2. Justice Kavanaugh delivered the majority opinion joined by Chief Justice Roberts and Justices Thomas, Alito, Sotomayor, Kagan, and Barrett. Justice Thomas filed a concurring opinion. Justice Jackson filed a dissenting opinion joined by Justice Gorsuch. Reversed and remanded.

Majority Reasoning: • (1) FIFRA's registration process mandates substantive EPA label review; after approval, manufacturers must use that label and cannot change it without prior agency authorization; • (2) Riegel v. Medtronic establishes that analogous agency approval creates binding federal "requirements" — EPA pesticide registration functions identically and carries the same preemptive force; • (3) Durnell's claim imposes a labeling requirement "in addition to or different from" the EPA-approved label, triggering FIFRA's express preemption clause and its mandate for nationwide uniformity.

Separate Opinions:

• Justice Thomas (concurring): Joined the majority fully; wrote separately to flag three constitutional concerns: FIFRA may exceed Congress's Commerce Clause authority, violate the non-delegation doctrine, and rely on a form of agency preemption the Supremacy Clause may not support.

• Justice Jackson (dissenting, joined by Gorsuch): FIFRA's misbranding prohibition — not EPA's label approval — constitutes the operative federal requirement. Missouri's failure-to-warn tort mirrors that prohibition, imposing nothing "in addition to or different from" federal law; § 136a(f)(2) confirms registration carries no preemptive force.

Implications: • (1) State-law failure-to-warn claims against federally registered pesticides face preemption nationwide, closing state courtrooms to injured consumers seeking damages; • (2) Plaintiffs must petition the EPA directly, then seek judicial review of agency decisions, rather than pursue state tort remedies — a longer, harder road with no individual damages award; • (3) Manufacturers across food, drug, medical device, and consumer product industries gain stronger preemption defenses under analogous federal labeling statutes.

The Fine Print:

• FIFRA § 136v(b) — "Uniformity": "A State shall not impose or continue in effect any requirements for labeling or packaging in addition to or different from those required under this subchapter."

• FIFRA § 136a(f)(2): "In no event shall registration of an article be construed as a defense for the commission of any offense under this subchapter. Such registration shall, however, be accepted as prima facie evidence that the pesticide, its labeling and packaging comply with the registration provisions of this subchapter."

Primary Cases:

• Bates v. Dow Agrosciences LLC (2005): State failure-to-warn tort claims qualify as labeling "requirements" under FIFRA's preemption clause; courts must assess whether those requirements exceed or differ from FIFRA's own mandates.

• Riegel v. Medtronic, Inc. (2008): FDA premarket approval of a medical device creates binding federal "requirements" under a nearly identical preemption clause, preempting state tort claims seeking additional or different safety measures.

Oral Advocates:

• Petitioner (Monsanto): Paul D. Clement of Clement & Murphy
• Respondent (Durnell): Ashley C. Keller of Keller Postman
• Amicus Curiae (United States): Sarah M. Harris of the Department of Justice