US supreme court blocks thousands of lawsuits over Roundup maker's pesticide warning labels

US supreme court blocks thousands of lawsuits over Roundup maker's pesticide warning labels

The US supreme court has found in favor of the former Monsanto company in a ruling that is expected to block thousands of lawsuits filed by people alleging the key ingredient in the weed killer Roundup causes cancer. The decision was made in a 7-2 vote, with Justice Brett Kavanaugh offering the majority opinion and Justice Ketanji Brown Jackson writing the dissenting opinion, joined by Justice Neil Gorsuch.

"Fifra expressly preempts Durnell's state-law failure-to-warn claim," reads the opinion written by Justice Kavanaugh, pointing to the Federal Insecticide, Fungicide and Rodenticide Act (Fifra).

In her dissenting opinion, Justice Jackson wrote that the Court "leaves Durnell without a remedy for the significant harms he has suffered."

The chemical has been classified a probable human carcinogen by an arm of the World Health Organization in 2015. Bayer maintains that its products don't cause cancer. The EPA has not required such a warning and has taken the position that glyphosate is "unlikely" to be carcinogenic. In the Thursday ruling, the supreme court upheld this argument: "In accordance with EPA's view that glyphosate is not likely to cause cancer in humans, EPA has not required labels on glyphosate-based pesticides like Roundup to include a cancer warning," the decision says.

In a statement, Bayer described the ruling as "good for science, farmers, and industries that depend on regulatory clarity for innovation."

Patti Goldman, senior attorney at the environmental legal non-profit Earthjustice, said: "The fact that EPA approved a pesticide label does not mean a product is safe, and it should not become a shield for companies that fail to warn about cancer risks."

The court's decision means the failure-to-warn claims included in several thousand lawsuits pending against Monsanto cannot go forward. Similarly, thousands of such claims pending against pesticide maker Syngenta cannot proceed. In the Syngenta cases, plaintiffs allege they developed Parkinson's disease due to exposure to the company's paraquat weed killer.

"Once again, the supreme court has sided with big business over people and the environment," said Tarah Heinzen, legal director of the green advocacy group Food and Water Watch.

Protesters at the court: "The People vs the Poison" protesters gather at the US supreme court on 27 April 2026 in Washington DC.