A California Appeals Court sided with the Center for Food Safety and the state of California in affirming that Monsanto’s glyphosate pesticide can be listed under Prop 65. The listing says glyphosate is a known carcinogen. Monsanto filed a lawsuit challenging a California announcement that it would be listing glyphosate, the active ingredient in Monsanto’s Roundup herbicide, under California’s Prop 65. The proposition requires notification and labeling of all chemicals known to cause cancer, birth defects, or other types of reproductive harm. Prop 65 also prohibits their discharge into drinking waters of the state. The Center for Food Safety then intervened in the case after Monsanto filed suit, saying the glyphosate listing under Prop 65 was correct and the public had a right to know when it’s being exposed to cancer-causing chemicals. In 2015, the International Agency for Research on Cancer (IARC) concluded that glyphosate is "probably carcinogenic." California subsequently issued the notice of intent to list glyphosate as a Proposition 65 chemical based on the IARC finding.