"Monsanto Co stepped up its defense of a widely used weed killer on Thursday by filing a lawsuit in California seeking to prevent glyphosate, the main ingredient in its Roundup herbicide, from being added to the state's list of known carcinogens.

The seed and agrochemicals company said it filed the suit against the state's Office of Environmental Health Hazard Assessment (OEHHA) and the agency's acting director, Lauren Zeise, in California state court, according to the filing seen by Reuters.

California law requires the state to keep a list of cancer-causing chemicals to inform residents of their risks."

Karl Plume reports for Reuters January 21, 2016. [2]