On November 27, 2017, a WLF Legal Pulse post by WLF Senior Litigation Counsel Cory Andrews discussed a lawsuit filed by makers and users of pesticides that include the chemical glyphosate against the California agency that administers Proposition 65. That law requires warnings on products that contain substances “known to the state of California” to cause cancer. On February 26, Eastern District of California Judge William B. Shubb imposed a preliminary injunction preventing the state from listing glyphosate as a carcinogen under Prop 65. The court held that the plaintiffs were likely to prevail on the First Amendment arguments in their suit. National Ass’n of Wheat Growers, et al. v. Zeise.

Under Prop 65, a substance must be listed if it is identified as a potential carcinogens by the International Agency for Research on Cancer (IARC), an international non-governmental entity. In 2015, IARC made that determination for glyphosate, triggering the automatic Prop 65 listing. IARC’s classification of glyphosate is contrary to the conclusions of many environmental regulators around the world, including the US EPA. Last November, a study published in the Journal of the National Cancer Institute reinforced those regulators’ conclusions that glyphosate was unlikely to pose a cancer hazard to humans.

To pass muster under the First Amendment, a commercial-speech mandate must require language that is “purely factual and uncontroversial.” The language must thus be factually accurate, and even if literally true, cannot be misleading. Judge Shubb found that the warning required for glyphosate is not factual or uncontroversial because it “conveys the message that glyphosate’s carcinogenicity is an undisputed fact, when almost all other regulators have concluded that there is insufficient evidence that glysophate causes cancer.”