According to Reuters, beginning July 7 California will add glyphosate, an herbicide and the active ingredient in Monsanto’s Roundup weed killer, to the state’s list of chemicals known to cause cancer (Proposition 65). In response, Monsanto has vowed to continue its legal fight against the designation and called the decision “unwarranted on the basis of science and the law.”
Listing glyphosate as a known carcinogen under California’s Proposition 65 would require companies selling the chemical in the state to add warning labels to packaging. Warnings would also be required if glyphosate is being sprayed at levels deemed unsafe by regulators. Monsanto and other glyphosate producers would have roughly a year from the listing date to re-label products or remove them from store shelves if further legal challenges are lost.
The Office of Environmental Health Hazard Assessment (OEHHA) 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.