U.S. Supreme Court blocks state cancer suits over Roundup, handing Bayer a major win

The U.S. Supreme Court ruled Thursday, by a 7 to 2 vote, that plaintiffs cannot use state law to sue Bayer over claims that it failed to warn that Roundup, its glyphosate-based weedkiller, may cause cancer. The decision, reported by CNBC, does not necessarily bar other types of lawsuits against the company, but it sharply limits the warning-based claims that have targeted Roundup for nearly a decade.

Justice Brett Kavanaugh wrote for the majority that the Environmental Protection Agency had found glyphosate safe for normal use and had not required a cancer warning on the label. Because federal pesticide law requires uniform labeling, he said states cannot demand additional or different warnings. Bayer said the ruling is good for science, farmers and industries that need regulatory certainty, and said it should significantly reduce pending and future Roundup litigation.

The case centered on John Durnell, who said repeated exposure to glyphosate caused his cancer. A Missouri jury awarded him more than $1 million in 2019, and a federal appeals court upheld that verdict. The Supreme Court has now reversed that outcome and sent the case back for further proceedings. Bayer’s shares jumped 18% in Frankfurt after the ruling.

The decision is expected to affect thousands of similar U.S. lawsuits. It also carries political weight for the Trump administration and the Make America Healthy Again movement, which opposed widespread glyphosate use and has argued that federal policy is too lenient on the chemical. Robert F. Kennedy Jr., now U.S. health secretary and a MAHA leader, had previously won a similar case in 2018 involving Monsanto. Justices Ketanji Brown Jackson and Neil Gorsuch dissented, saying courts have often rejected the federal preemption argument and that the suits should have been allowed to continue.