← All Cases
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.

Argued April 27, 2026Official Transcript ↗

Oral Argument Recording

Via Spotify ↗

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 Circuit Split

Circuits disagree on whether FIFRA's preemption provision bars state-law failure-to-warn claims against pesticide manufacturers when the claim is based on the absence of a warning that the EPA did not require. The split affects product liability litigation involving agricultural chemicals and consumer pesticide products.

FIFRA preempts failure-to-warn claims

Holds that FIFRA preempts state-law failure-to-warn claims that would effectively require labeling different from or in addition to what FIFRA and EPA regulations permit.

FIFRA does not preempt failure-to-warn claims

Holds that FIFRA does not preempt state-law failure-to-warn claims because such claims impose requirements 'parallel to' rather than 'in addition to' FIFRA's labeling requirements.

The Arguments

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

Legal Terminology

Analysis & Opinions

SCOTUSblogAbbe R. Gluck2026-05-01
State and federal courts jockey for power in the Roundup case and other mass public harms

The Supreme Court heard oral arguments in Monsanto Co. v. Durnell, a case about whether federal pesticide labeling law preempts a Missouri jury's $1.25 million award to a gardener who claimed Roundup caused cancer. The case raises significant questions about the balance of power between state and federal courts in mass tort litigation involving public harms.

SCOTUSblogKelsey Dallas2026-04-28
Justices debate who gets to decide that pesticide labels need a cancer warning

The Supreme Court heard oral arguments in a case involving Monsanto's Roundup herbicide products and whether state-law claims requiring cancer warnings on pesticide labels are preempted by federal law. The dispute centers on the main active ingredient glyphosate and who gets to decide whether such labels need a cancer warning. The case could have broad implications for pesticide regulation and state tort lawsuits.

NYT PoliticsAbbie VanSickle2026-04-27
Supreme Court Appears Divided Over Roundup Weedkiller Case

The Supreme Court appeared divided during oral arguments over whether federal law preempts state-law lawsuits alleging that Monsanto's Roundup weedkiller causes cancer. The outcome could affect thousands of product liability lawsuits against the herbicide's maker.

Washington PostJustin Jouvenal2026-04-27
Supreme Court considers blocking lawsuits alleging weed killer causes cancer

The Supreme Court is considering whether federal pesticide labeling law preempts state-court lawsuits by thousands of cancer victims who allege Monsanto's Roundup herbicide caused their illness. The case represents one of the largest waves of product liability litigation in U.S. history.

SCOTUSblogKelsey Dallas2026-04-23
Justices to hear dispute over cancer warnings on pesticide labels

The Supreme Court is set to hear oral arguments in Monsanto Company v. Durnell, which asks whether federal pesticide labeling law preempts state requirements that cancer warnings be added to pesticide product labels. The case has massive implications, involving over 100,000 lawsuits and billions of dollars in potential liability related to Monsanto's products. The dispute puts the court at the center of a battle involving the international scientific community, federal and state policymakers, and the pesticide industry.