Posted January 26, 2016

Monsanto filed a lawsuit against California’s Office of Environmental Health Hazard Assessment seeking to keep a main ingredient in its Roundup herbicide off the state’s list of cancer-causing chemicals.

The company filed suit last week in California’s Superior Court in Fresno, attempting to prevent the state agency from adding glyphosate to a list the state keeps in accordance with state law. The lawsuit also names OEHHA’s acting director, Lauren Zeise, as a defendant.

The lawsuit is the most recent effort by Monsanto to defend glyphosate and its Roundup product against claims the herbicide causes cancer.

Last September, the state agency planned to list glyphosate under Proposition 65, a state initiative enacted in 1986 to notify residents about cancer-causing chemicals. The agency says the notice is required after a World Health Organization research committee classified glyphosate as a probable human carcinogen.

In its suit, Monsanto said that numerous regulatory agencies and independent scientists have evaluated glyphosate over more than forty years of use and concluded that glyphosate does not present a carcinogenic risk to humans.

The OEHHA included glyphosate on its list of carcinogens, stating that state law requires certain substances identified by the International Agency for Research on Cancer (IARC) to be listed as cancer-causing.

Monsanto, on the other hand, claims that OEHHA previously concluded in 2007 that glyphosate is unlikely to pose a cancer hazard to humans.

A copy of the court filing can be viewed here.