Warning Glyophosphate: California Wins Legal Defense

In a lawsuit led by Monsanto, a California Appellate Court affirmed the state can require labeling of products containing glyphosate herbicide as toxic under drinking water law. 13 states have state or local glyophosphate bans or restrictions.

According to the Center for Food Safety (CFS), glyphosate -- a broad spectrum herbicide -- is used widely used in agriculture, public parks and residential landscape and garden.

It is the most heavily used pesticide in the world, in large part due to the proliferation of Monsanto's genetically engineered Roundup Ready crops that are resistant to glyphosate," said an announcement about the state of California's, and CFS's legal win, against a lawsuit brought by Monsanto and U.S. farm groups.

A California Appellate Court, sided with the state of California and CFS affirming that glyphosate pesticide can be listed as a probable carcinogen under Proposition 65. The lawsuit challenged the 2015 announcement by California's Office of Environmental Health Hazard Assessment (OEHHA) that it intended to list glyphosate, the active ingredient in Monsanto's herbicide, Roundup, under Proposition 65, which passed in 1986.

Glyophosphate Products to Get Warning Label

Proposition 65 requires notification and labeling of all chemicals known to cause cancer, birth defects or other reproductive harm, and prohibits their discharge into drinking waters of the state. CFS intervened in the case, defending the listing of glyphosate as a carcinogen and the public's right to know when it is being exposed to cancer-causing chemicals.

In 2015, the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) 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. Under Proposition 65, no person in the course of doing business may knowingly or intentionally expose any individual to a chemical known to the state to cause cancer or reproductive toxicity without first giving a clear and reasonable warning.

The discharge of such chemical into a source of drinking water is prohibited. CFS said the court ruling enforces California's requirement for glyphosate products.

"This is a huge win for all Californians — and a huge loss for Monsanto — as it upholds our right to protect ourselves and our environment from unnecessary and unwanted exposure to the dangerous chemical, glyphosate," said Adam Keats, senior attorney at CFS.

CFS is a public interest organization has been heavily involved with regulation of glyphosate, raising awareness about use the organization says fosters herbicide-resistant weeds and increases the use of the herbicide.

Get a CFS fact sheet about the IARC determination.

Access the original announcement on the CFS website.

Review public comments on California's 2016 decision.

Decision Coincides with EPA's Glyophosphate Re-Evaluation Comment Period 

While WHO has labeled the herbicide as a probable carcinogen, the U.S. Environmental Protection Agency (EPA) guidelines allow it's use. Monsanto's Roundup, as well as many other weed killers that contain glyphosate-based herbicides are readily available for purchase nationwide.

With the California ruling to list the ingredient as a warning, glyophosphate is not banned in the state.

Coinciding with the announcement, EPA is currently re-evaluating glyophosphate on a regular 15-year registration cycle to reassess risk and review its current use guidelines. The public comment period is open until April 30, 2018.

Local Government Glyophosphate Bans & Restrictions

According to the law firm Baum Hedlund Aristei & Goldman, which represents those that being lawsuits against Monsanto, local jurisdictions, as well as states other nations, have taken restricted or banned glyphosate.

The following list of U.S. local and state governments and related glyophosphate restrictions or bans in 13 states can be found on the firm's website.


  • Carlsbad, California – The City council voted unanimously to adopt a policy that makes organic pesticides the preferred method for killing weeds. “Asked to choose between aesthetics and public health…I’m going to choose public health every time,” said Councilwoman Cori Schumacher.



A growing number of Connecticut towns, including Branford, Cheshire, Granby, Essex, Greenwich, Manchester, Plainville, Roxbury, Watertown and Woodbridge have adopted bans or restrictions on glyphosate use. The state also has Public Act 09-56 to eliminate the use pesticides in K-8 schools.


  • North Miami, Florida – City council approved a plan calling for the gradual reduction of pesticide use on city property and a study on alternative pesticides.



Dozens of cities and townships in Maine have adopted local ordinances restricting or banning pesticides and herbicides.




New Mexico

New Jersey

New Jersey has State and local ordinances encouraging Integrated Pest Management programs to eliminate or drastically reduce the use of pesticides. At least 15 city school districts and over a dozen other parks and recreation departments in the state have enacted IPM programs.

New York

New York’s Park and Recreation Department has measures to eliminate or reduce pesticide and herbicide use in areas under its control.


  • Cuyahoga County, Oregon – Local ordinance prohibits the use of pesticides on county-owned land, and established the adoption of an Integrated Pest Management program for county-owned properties.
  • South Portland, Oregon – Passed a pesticide plan that discourages property owners from using certain pesticides and herbicides.

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