Supreme Court ruling blocks thousands of lawsuits against maker of Roundup weedkiller

The Supreme Court is set to consider Bayer’s appeal in a Roundup-related fight over who gets to decide whether warning labels on pesticides must include cancer warnings. The question is whether federal pesticide approval by the U.S. Environmental Protection Agency should block state-court claims and jury findings that companies failed to warn.

The case centers on a Missouri lawsuit in which a jury awarded damages to a man who said he developed non-Hodgkin’s lymphoma after long-term exposure to Roundup’s active ingredient, glyphosate, including from spraying it in his neighborhood. Bayer (which owns Monsanto, the original Roundup maker) argues that federal law preempts the state claim—because Bayer complied with the federally required pesticide registration process and the EPA approved the product’s label without a cancer warning.

Plaintiffs and critics argue that even if the product is federally registered, a company can still be held liable if a label is later alleged to be inadequate under state “failure to warn” standards. They frame the issue as one of timing and oversight: whether states can require additional warnings based on evolving scientific evidence when federal regulators have not changed the label.

While the dispute does not turn on the Supreme Court deciding whether glyphosate causes cancer, it could determine the fate of tens of thousands of similar lawsuits. The broader reporting notes that Bayer has already set aside large sums to resolve many claims and has sought legislation in some states to limit new litigation—aiming to reduce jury exposure and inconsistent outcomes across jurisdictions.