In 2017, a national coalition of farming interests, food producers, and pesticide manufacturers came together to file a lawsuit against the State of California through its regulatory agency the California Office of Environmental Health Hazard Assessment (“OEHHA”) for listing the chemical glyphosate on a list of chemicals known by the State to cause cancer. Known as Nat’l Ass’n of Wheat Growers et. al. v. OEHHA, No. 2:17-cv-02401 (E.D. Cal.), the case is currently awaiting the court’s determination on whether to let the case go to trial. Due to how widely used glyphosate is, the outcome of this case will likely have far-reaching impacts.

Glyphosate is one of the widest used pesticides in the United States. Used primarily in Roundup, glyphosate is approved by the federal government for use on over 100 food crops. The Environmental Protection Agency (“EPA”) has approved glyphosate for use under the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”) for several decades, and maintains that glyphosate poses no risk to human health when it is used according to label instructions. Glyphosate has been studied for decades, and until recently has largely been considered to be non-carcinogenic.

The Safe Drinking Water and Toxic Enforcement Act of 1986, commonly known as Proposition 65, was enacted by California voters in 1986. Proposition 65 prevents California businesses from exposing citizens to chemicals known to the State to cause cancer without providing a required warning, and from knowingly discharging such chemicals into the environment where the chemical would be likely to enter drinking water. Proposition 65 requires the OEHHA to maintain a list of chemicals known to the State of California to cause cancer. Through a function of the proposition, any substance identified as a carcinogen by International Agency for Research on Cancer (“IARC”) is automatically added to OEHHA’s list of chemicals known to cause cancer. IARC published a report in March, 2015 which identified glyphosate as a “probable human carcinogen.” That study kicked off the process which lead OEHHA to list glyphosate under Proposition 65 as a chemical known to the State of California to cause cancer.

This lawsuit was filed soon after glyphosate was listed under Proposition 65. The plaintiffs, primarily a collection of grower associations, state farm bureaus, and glyphosate manufacturers, maintain that glyphosate does not cause cancer. They repeatedly refer to multiple studies conducted by EPA and two studies conducted by OEHHA in 1997 and 2007 which all conclude that glyphosate is non-carcinogenic. The complaint filed by the plaintiffs alleges that by listing glyphosate under Proposition 65 as a known carcinogen, OEHHA has committed multiple violations of the United States Constitution.

First, the plaintiffs allege that requiring businesses to put warning labels on any products containing glyphosate would violate the Free Speech Clause of the First Amendment by compelling speech that is “false and misleading.” Second, the plaintiffs allege that OEHHA has violated Article VI, Clause 2 of the United States Constitution, commonly known as the Supremacy Clause, which provides that state laws that conflict with federal law are preempted and have no effect. The plaintiffs argue that if Proposition 65 required all products containing glyphosate to be sold with a label stating that glyphosate was known to cause cancer, it would violate the Federal Food, Drug, and Cosmetic Act (“FDCA”) which prohibits false or misleading labeling of food. Finally, the plaintiffs allege that OEHHA has violated the Due Process Clause of the Fourteenth Amendment which provides that “[n]o state shall . . . deprive any person of life, liberty, or property, without due process of law.” According to the plaintiffs, OEHHA violated the Due Process Clause by relying only on IRAC’s 2015 report to conclude that glyphosate causes cancer instead of conducting any of its own studies. The plaintiffs conclude that because OEHHA has not conducted its own studies into the whether glyphosate causes cancer, the State of California does not know that glyphosate is carcinogenic and therefore has no rational basis for listing glyphosate as a chemical known to the State to cause cancer.

Currently, the court is considering whether to allow the case to proceed to trial or whether it will issue an opinion through summary judgment. Courts will issue opinions through summary judgment when they have concluded that there are no factual issues for a jury to consider and that the case can be decided on issues of law without going to trial. The plaintiffs in this case have requested summary judgment, indicating that they feel that the facts in this case are undisputable and that the only role of the court would be to decide whether or not the defendant violated the law. The defendants have also asked the court to grant summary judgment, arguing that since the case has been filed three juries in other lawsuits have concluded that glyphosate does cause cancer, meaning that there can be no dispute of fact with regard to glyphosate being a carcinogen.

Whatever the court decides, its opinion will likely have far-reaching effects. Many of the plaintiffs in this case represent growers who operate outside of California, but ship their products to the State for sale. If glyphosate is listed under Proposition 65, then any produce which has been sprayed with glyphosate that is sold in California will be required to have a warning label, even if it is grown in a different state. Additionally, since this case was filed, multiple lawsuits have been brought by private citizens against Monsanto Company (“Monsanto”) asserting that glyphosate manufactured by the company gave them cancer. While several of those suits are ongoing, the three that have gone to trial have resulted in large jury awards for the plaintiffs. However the court rules, its decision has the potential to affect anyone who uses glyphosate.


To read the complaint in Nat’l Ass’n of Wheat Growers et. al. v. OEHHA, click here.

For more National Agricultural Law Center information on lawsuits concerning glyphosate, click here.

For more National Agricultural Law Center resources on pesticides, click here.