Center Files Amicus Brief To Support Prop 65 Warnings on Glyphosate – and the Government’s Ability to Inform the Public About Health Dangers

February 19, 2021

The Center, along with Berkeley Law professor Claudia Polsky, filed an amicus brief in National Wheat Growers Association v. Becerra, a case challenging California’s Prop 65 warning requirement on products containing glyphosate. Glyphosate is the main ingredient in Monsanto’s weed-killer, Roundup, and has been identified by the International Agency for Research on Cancer as a probable carcinogen. The Center supported the State of California against Monsanto’s First Amendment challenge to the state’s labeling requirement.

There is disagreement among scientific bodies about whether or not glyphosate — the world’s most widely used weed killer — causes cancer. In 2015, the International Agency for Research on Cancer (IARC) determined that glyphosate is probably carcinogenic to humans. However, the U.S. Environmental Protection Agency’s (EPA) position is that glyphosate is safe. 

California juries have returned several multi-million dollar verdicts against Monsanto in favor of individuals who developed non-Hodgkin's lymphoma (NHL) after extensive use of Roundup. Those cases unearthed evidence of Monsanto’s distortion of the science, attempts to influence government regulators (including, importantly, the EPA), and campaign to discredit IARC. In 2020, Monsanto announced its willingness to pay $10 billion to resolve nearly 100,000 lawsuits regarding Roundup’s carcinogenicity, in one of the largest settlements in U.S. civil litigation. As part of the settlement, Monsanto agreed to provide to consumers a web link on Roundup product labeling that links to information about the chemical’s possible connection to cancer. 

Since IARC determined that glyphosate is a probable carcinogen, the State added glyphosate to its list of products requiring Prop 65 warnings — the ubiquitous warnings seen in various buildings and on many products in California. The warning at issue includes information about the IARC determination as well as the EPA’s contrary view. Monsanto, and the National Association of Wheat Growers, challenged the requirement as violating their First Amendment right to free speech.

The amicus brief filed by the Center and Professor Polsky highlights a signal First Amendment principle: the provision of information. The Prop 65 warning, the brief explains, provides salient factual information to individual consumers in the marketplace, as well as to companies upstream in the chain of commerce that incentivizes them to produce, distribute, and sell safer products. The warning meets the lenient test applied to government-required disclosures. The disclosure on products containing glyphosate is factual, uncontroversial, and supports the government’s interest in protecting public health by informing Californians about potentially toxic chemicals in everyday products. 

Manufacturers of toxic substances have a demonstrated history of attempting to muddy the science to create confusion about the dangers of their products. Here, numerous courts have concluded that Monsanto not only attempted to conceal the dangers of glyphosate, but also used its influence to generate factual confusion and controversy on which it then circularly relied to argue that the Prop 65 warning was not “factual and uncontroversial.” 

Prop 65 warnings play a valuable role in informing the public about potentially hazardous substances. As the Center’s brief argues, the First Amendment should not be used as a weapon against factual disclosures designed to improve public health and allow individuals to make informed decisions.