California has no plans to change its rule that certain products containing the herbicide glyphosate require warnings to consumers that it could cause cancer, despite The Environmental Protection Agency (EPA) saying the regulation misleads the public.

State officials declared glyphosate, which is in weedkillers like Roundup, a carcinogen in 201. They added it to California’s Proposition 65 list, which requires warnings on consumer products if they pose a health risk.

The glyphosate cancer warnings were scheduled to start appearing in summer of 2018. But a judge delayed the rule while Monsanto challenged the decision in court.

The EPA protested the plan in an August 8 statement, saying it was taking action to provide accurate risk information to consumers.

“The State of California’s much criticized Proposition 65 has led to misleading labeling requirements for products, like glyphosate, because it misinforms the public about the risks they are facing,” EPA announced in a statement.

But on August 12, California’s Office of Environmental Health Hazard Assessment (Oehha) has hit back at the agency’s criticism. It said that its scheme has reduced or eliminated exposure to dozens of toxic substances. 

"OEHHA added glyphosate to the Proposition 65 list of carcinogens in July 2017, based on a finding by the World Health Organization’s International Agency for Research on Cancer (IARC) that glyphosate is both an animal carcinogen and “probably carcinogenic to humans”," it said.

"The listing was also supported by IARC’s finding that studies of humans exposed to different glyphosate formulations in different geographic regions at different times reported similar increases in the same type of cancer - non-Hodgkin lymphoma."

It added that decision was upheld by the California’s Fifth District Court of Appeal following legal challenges by Monsanto.

"OEHHA objects to US EPA’s characterization of any warning concerning glyphosate’s carcinogenicity as “a false claim”," it went on to say.

"US EPA’s assertion is based on its view that glyphosate is not likely to cause cancer in humans. That position conflicts with the determination made by IARC and its scientific panel, which included experts from the US National Cancer Institute, US EPA and the U.S. National Institute of Environmental Health, who carefully evaluated the extensive scientific evidence on glyphosate’s carcinogenicity. 

"It is disrespectful of the scientific process for US EPA to categorically dismiss any warnings based on IARC’s determinations as false."

It said through Proposition 65, California has educed or eliminated exposures to toxic chemicals from a range of products.