Appeals court blocks California warning requirement for glyphosate

November 7, 2023

Photo by Ken Lund under CC BY-SA 2.0 DEED license

A divided federal appeals court on Tuesday upheld an injunction barring California from requiring businesses to warn consumers that glyphosate, the active ingredient in Roundup weedkiller, causes cancer.

In a 2-1 decision, the 9th U.S. Circuit Court of Appeals said it was unconstitutional for California to require Bayer AG’s (BAYGn.DE) Monsanto unit, which makes Roundup, and some agricultural producers to provide the warning under a state law known as Proposition 65.

The court said the warning conveyed the “at best, disputed” message that glyphosate is unsafe, and that requiring objectors to convey a “controversial, fiercely contested message that they fundamentally disagree with” violated the First Amendment.

The office of California Attorney General Rob Bonta, which defended the warning, did not immediately respond to requests for comment. Neither Bayer nor lawyers for the company and the agricultural producers immediately responded to similar requests

Bayer has faced extensive litigation over whether Roundup causes cancer since it spent $63 billion to buy Monsanto in 2018.

Reporting by Jonathan Stempel in New York; Editing by Richard Chang