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2025 Term · 24-1068

Monsanto Company v. John L. Durnell

Whether the Federal Insecticide, Fungicide, and Rodenticide Act preempts state law failure-to-warn claims based on allegedly inadequate product labeling when the EPA has not required the specific warning.

Oral argument scheduled for April 27, 2026 at 10:00 a.m. ET

Background & Facts

John L. Durnell brought a failure-to-warn lawsuit against Monsanto Company, alleging that Monsanto's herbicide product failed to adequately warn of health risks. The case centers on whether state tort law allows such claims to proceed when the EPA, the federal agency responsible for regulating pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), has not mandated the additional warnings that Durnell claims should have been included on the product label.

The Missouri Court of Appeals, Eastern District, decided the case on February 11, 2025, and the case was subsequently appealed to the Supreme Court. Monsanto petitioned for certiorari, arguing that federal law governing pesticide labeling preempts state-law warning claims. The Supreme Court granted the petition on January 16, 2026, limiting review to the narrow question of FIFRA preemption in the label-warning context.

Why This Case Matters

This case addresses a critical intersection between federal regulatory authority and state tort law in the agricultural chemicals industry. A decision favoring Monsanto could significantly limit consumers' ability to bring failure-to-warn lawsuits in state court when federal regulators have approved a product's labeling, potentially shielding manufacturers from liability for allegedly inadequate warnings. Conversely, a decision favoring Durnell would preserve state law remedies and signal that FIFRA does not completely preempt warning-based tort claims. The outcome will affect not only pesticide manufacturers but also the broader landscape of product liability law, particularly for FDA-regulated and EPA-regulated products where state and federal standards may diverge.

The Arguments

Oral argument is scheduled for April 27, 2026 at 10:00 a.m. ET. The positions below reflect each party’s written briefs. This section will be updated following argument.
Monsanto Companypetitioner

FIFRA preempts state law failure-to-warn claims when the EPA has not required the disputed warning on a product label. Federal pesticide labeling is comprehensively regulated by the EPA, and allowing state courts to impose additional warning requirements would create conflicting regulatory schemes and undermine uniform federal standards.

  • FIFRA establishes exclusive federal control over pesticide labeling requirements, and the EPA's approval of a label represents a federal determination that the label is adequate
  • Permitting state-based warning claims would allow plaintiffs to circumvent the EPA's regulatory judgment and create a patchwork of state-imposed label requirements
  • Failure-to-warn claims inherently challenge the adequacy of EPA-approved labels, which is a federal regulatory function
  • Multiple amicus briefs from agricultural and industry groups support preemption to ensure regulatory uniformity and avoid conflicting state requirements
John L. Durnellrespondent

FIFRA does not preempt state law failure-to-warn claims because the statute does not explicitly preempt such claims and preserves traditional state tort remedies. The EPA's approval of a label does not constitute a positive federal determination that additional warnings are unnecessary or that state law claims are impermissible.

  • FIFRA contains no express preemption clause eliminating state law warning claims, and courts should not infer preemption absent clear congressional intent
  • The EPA's labeling approval is a minimum federal standard, not a ceiling that precludes state law from requiring more protective labeling
  • State failure-to-warn claims operate independently from federal labeling requirements and do not conflict with federal regulatory authority
  • Preemption would eliminate an important remedy for consumers harmed by allegedly inadequate warnings approved by federal regulators

Precedent Cases Cited

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