U.S. District Court Denies California Attorney General’s Request to Reconsider Holding that Proposition 65 Warnings for Glyphosate in Herbicide Products are Misleading

Environmental Law  

June 19, 2018


On June 12, 2018, the United States District Court for the Eastern District of California denied the California Attorney General’s request for the court to reconsider its decision in February that California cannot require Proposition 65 warnings on herbicide products containing glyphosate.  Nat’l Ass’n of Wheat Growers v. Zeise, Case No. 2:17-2401 (E.D. Cal. June 12, 2018).  As we reported in February, the court previously issued a preliminary injunction finding that Proposition 65 warnings for glyphosate are misleading and violate the First Amendment because there is insufficient evidence to conclude that glyphosate causes cancer.

California’s Proposition 65, also known as the Safe Drinking Water and Toxic Enforcement Act of 1986—or “Prop. 65”—prohibits businesses from exposing people to chemicals on the Prop. 65 List without providing “clear and reasonable” warnings.  Chemicals can be added to the Prop. 65 List based on California’s analysis of current scientific information and in situations where, as determined by other outside entities including the United States Environmental Protection Agency (USEPA) and the International Agency for Research on Cancer (IARC), a substance is a human carcinogen.

In 2015, IARC classified glyphosate as “probably carcinogenic” to humans.  However, other entities including USEPA concluded that there is no evidence that glyphosate causes cancer.  Despite USEPA’s position on the issue, on July 7, 2017, the Office of Environmental Health Hazard Assessment (OEHHA) added glyphosate to the Prop. 65 List based on IARC’s 2015 finding.

Monsanto, the manufacturer of the popular herbicide product known as Roundup and several farming associations challenged OEHHA’s listing based on the First Amendment to the United States Constitution.  Although the court’s decision in February dealt with the plaintiffs’ motion for a preliminary injunction, the court held that the plaintiffs had a substantial likelihood of success on the merits.  Pending final resolution of the matter, the State cannot require the plaintiffs to include a Prop. 65 warning for glyphosate on their herbicide products.  The court explained that based on the evidence before the court, “the required warning for glyphosate does not appear to be factually accurate and 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 glyphosate causes cancer.”  Citing USEPA’s conclusion that there is no evidence that glyphosate causes cancer, the court then reasoned that it is “inherently misleading for a warning to state that a chemical is known to the state of California to cause cancer based on the finding of one organization (which . . . only found that substance is probably carcinogenic)[.]”

The California Attorney General filed a motion to alter or amend the court’s February decision, arguing that reconsideration was warranted based on new evidence, including a newly-adopted no significant risk level for glyphosate and a California Court of Appeal’s decision dismissing a separate state court challenge regarding OEHHA’s reliance on IARC’s glyphosate classification to add glyphosate to the Prop. 65 List.  Monsanto Co. v. OEHHA, 22 Cal.App.5th 534 (5th Dist. 2018).  The federal court concluded that the “new evidence” the Attorney General provided did not change the ultimate conclusion that Prop. 65 warnings for glyphosate are not purely factual and uncontroversial (i.e., not misleading), thus violating the First Amendment. 

The court’s decision will remain in place until it resolves the issue on the merits.  Because the plaintiffs already established a substantial likelihood of success on the merits, it is possible that the court will ultimately issue a permanent injunction preventing California from requiring Prop. 65 warnings on herbicide products containing glyphosate.  If Monsanto is successful, glyphosate will remain Prop. 65-listed, but no Prop. 65 warning will be required, and, more importantly, a door will be opened for other challenges to Prop. 65 warning requirements where the scientific evidence behind the listing of the chemical is less than clear. 

For assistance in complying with Prop. 65 enforcement matters, please contact us.