Monsanto v. Durnell
In brief
The Supreme Court sided with Monsanto on Durnell’s warning claim, blocked that state claim under federal pesticide law, and sent the case back to the Missouri appeals court.
- Where it stands
- Decided
Decided 7-2 · June 25, 2026 · Opinion by Justice Thomas
- What it’s about
- Monsanto challenges state court rulings holding it liable for damages from its Roundup herbicide product. The case addresses federal preemption of state tort claims for EPA-approved pesticide labels.
- Who it affects
- The ruling blocks Durnell’s state claim that Roundup’s label needed a cancer warning. The Missouri appeals court must apply that ruling when the case returns.
Summary: written with AI from the case record.
What it's about
The dispute shows how federal pesticide-label rules can limit state lawsuits claiming that a product needed a stronger warning.
Question presented
Does the Federal Insecticide, Fungicide, and Rodenticide Act preempt a label-based failure-to-warn claim where EPA has not required the warning?
What the Court decided
Holding
FIFRA 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. 707 S. W. 3d 828, reversed and remanded.
- Result
- Reversed
The vote
From the opinions
“Roundup’s label did not (and still does not) include any warning about the risk of developing cancer.”
What's next
The Missouri appeals court will take the case back and apply the Supreme Court’s ruling. Any further court steps must follow the decision that FIFRA overrides Durnell’s warning claim.
Docket activity
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More questions
- What did the Supreme Court decide in Monsanto v. Durnell?
- It ruled that FIFRA overrides Durnell’s warning claim because the claim would require Monsanto to add a cancer warning to Roundup’s label.
- Who won the warning-claim issue in Monsanto v. Durnell?
- Monsanto won because the Court blocked Durnell’s claim that Roundup needed a cancer warning. The case returns to the Missouri appeals court.
- What happens next in Durnell’s case?
- The Missouri appeals court will take the case back and apply the Supreme Court’s ruling. It must treat Durnell’s warning claim as blocked by FIFRA.
- What did Justice Jackson say about Monsanto v. Durnell?
- Justice Jackson disagreed with the Court, and Justice Gorsuch signed onto her dissent. She said Roundup’s label lacked a cancer warning.
Sources
Primary materials plus reporting. Best-effort analysis: this explainer relies on a mix of primary materials and trusted secondary sources. Official filings and opinions remain authoritative.