Supreme Court shields Monsanto from state Roundup cancer warning claims

The Supreme Court on June 25 ruled 7-2 that Monsanto cannot be held liable under state law for failing to warn that Roundup’s label lacked a cancer warning, handing Bayer a major victory in Monsanto Co. v. Durnell. The justices held that the Federal Insecticide, Fungicide, and Rodenticide Act preempts John Durnell’s Missouri failure-to-warn claim because the Environmental Protection Agency had not required a cancer warning on the glyphosate-based herbicide’s label.

Durnell sued in Missouri state court in 2019, saying he had used Roundup products for about 20 years and later developed non-Hodgkin’s lymphoma. A jury awarded him more than $1 million, the Missouri Court of Appeals affirmed the verdict, and the Supreme Court then took up the narrow question of whether federal pesticide law overrides state-law warning claims when EPA has not ordered a cancer warning.

Bayer puts the broader Roundup litigation at more than 100,000 claims. Bayer, which acquired Monsanto in 2018, also announced on February 17, 2026, a proposed nationwide class settlement designed to resolve current and future Roundup claims alleging non-Hodgkin lymphoma injuries, with funding of up to $7.25 billion over as long as 21 years. The settlement would not affect claims tied to pending appeals or those outside the deal, leaving some plaintiffs with separate paths still open.

EPA has repeatedly concluded that glyphosate is not likely to be carcinogenic to humans, while the International Agency for Research on Cancer classified glyphosate in March 2015 as probably carcinogenic to humans, based on limited evidence in people and sufficient evidence in animals.