Court Upholds CA Reliance on Expert Science Against Monsanto

In a major victory for public health and independent science last week, a California Court of Appeal ruled against Monsanto and for California voters’ reliance on the findings of expert scientific bodies to identify dangerous chemicals. The court upheld California’s listing of glyphosate – the active ingredient in the Monsanto’s herbicide Roundup – as a carcinogen based on the findings of the World Health Organization’s International Agency for Research on Cancer (IARC). IARC is a widely respected scientific body with decades of experience in evaluating carcinogens.

“The IARC Monographs have made, and continue to make, major contributions to the scientific underpinning for societal actions to improve the public’s health.”

- More than 100 scientists who work on identification and evaluation of human carcinogens, from Pierce et al., IARC Monographs: 40 Years of Evaluating Carcinogenic Hazards to Humans 123:6 Envtl. Health Persps. 507, 508 (June 2015)

Monsanto may not like the results, but that doesn’t make IARC wrong, nor does it make it wrong for California’s voters to rely on IARC. In fact, that independent expertise is precisely what California voters were looking for.

In passing California’s Proposition 65, voters—frustrated by the lack of progress by state agencies—chose to also rely on the findings of expert scientific bodies, including IARC, as an independent basis for adding to the state’s list of chemicals that cause cancer.

In 2015, IARC concluded that glyphosate is a probable human carcinogen, i.e. there is sufficient evidence of carcinogenicity in experimental animals and some evidence of carcinogenicity in humans. So, California moved forward with the process for including glyphosate on the Proposition 65 list. Monsanto then attacked California voters’ decision to rely on IARC for listing and argued it was unconstitutional. The trial court rejected Monsanto’s arguments last year, and California has now listed glyphosate as “known to the state to cause cancer.” Last week, the appellate court agreed with the trial court and ruled against Monsanto.

This is an important victory for public health and science.


This blog provides general information, not legal advice. If you need legal help, please consult a lawyer in your state.

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