At least one federal appellate judge seemed deeply skeptical Wednesday of California’s newest proposed cancer warning for a chemical in the popular weedkiller Roundup, suggesting a lack of consensus among the scientific community on the issue could tank the new label’s language.

Judge Consuelo Callahan of the U.S. Court of Appeals for the Ninth Circuit, questioned the state’s argument that the latest language—required under a law passed by California voter initiative—contains noncontroversial facts and an injunction blocking the warning should be lifted.