The herbicide glyphosate, the main ingredient in Monsanto’s weed killer Roundup, will be classified by California as a carcinogen, “known to the state to cause cancer.” The state’s Office of Environmental Health Hazard Assessment reported the news June 26, although it will officially take effect July 7.

Monsanto sued the state earlier this year to prevent the listing, but lost. However, the St. Louis-based company is appealing the ruling, which forces Monsanto, and any other company using glyphosate, to issue a warning label on packaging. The state environmental office told Reuters that Monsanto has not been granted a stay so the listing will go ahead next month despite the appeal. 

“This is not the final step in the process, and it has no bearing on the merits of the case,” said Scott Partridge, Monsanto’s vice president of global strategy, in an email. “We will continue to aggressively challenge this improper decision.” He added that the listing is “unwarranted on the basis of science and the law.”