A federal judge in California has blocked efforts by the state to require cancer warning labels on Bayer-Monsanto’s signature weedkiller, Roundup.

Glyphosate, the active ingredient in Roundup, is the most widely used herbicide in the world. In 2015, it was classified as “probably carcinogenic” to people by the International Agency for Research on Cancer, or IARC. The IARC has steadfastly defended that decision despite ongoing attacks by Monsanto.

In 2017, glyphosate was also listed by the California Office of Environmental Health Hazard Assessment, or OEHHA, as a chemical known to the state to cause cancer. That OEHHA decision set in motion plans to list glyphosate as a chemical known to cause cancer under California’s Proposition 65 law requiring warning labels on products that contain carcinogenic chemical ingredients. But U.S. District Judge William B. Shubb ignored OEHHA’s listing.

“This decision, while cheered on by Bayer-Monsanto and the agricultural chemical industry, is a blow to the right of every Californian to know whether widely available, widely used products like Roundup could cause cancer,” said EWG President Ken Cook, himself a California resident. “The judge clearly ignored the overwhelming science that compelled both IARC and California’s top scientists to sound the alarm over glyphosate’s risks.”