Glyphosate, an herbicide and the active ingredient in Monsanto Co.’s popular Roundup weedkiller, will be added to California’s list of chemicals known to cause cancer effective next mont the state’s Office of Environmental Health Hazard Assessment said on Monday.
Creve Coeur-based Monsanto vowed to continue its legal fight against the designation and called the decision “unwarranted on the basis of science and the law.”
The listing is the latest legal setback for the seeds and chemicals company, which has faced increasing litigation over glyphosate since the World Health Organization’s International Agency for Research on Cancer said that it is “probably carcinogenic” in a controversial ruling in 2015.
The California agency said the designation of glyphosate under Proposition 65 will proceed following an unsuccessful attempt by Monsanto to block the listing in trial court and after requests for stay were denied by a state appellate court and the California’s Supreme Court.
Monsanto’s appeal of the trial court’s ruling is pending.