California said it will list glyphosate, the main compound in Monsanto's Roundup herbicide, as a chemical known to cause cancer starting July 7 -- a determination delayed by a Monsanto lawsuit. File Photo by Mohammad Kheirkhah/UPI | License Photo

June 27 (UPI) -- The California Environmental Protection Agency said it will list glyphosate, the main compound in Monsanto's Roundup herbicide, as a chemical known to cause cancer.

The California EPA's Office of Environmental Health Hazard Assessment said it will add glyphosate to its state-wide list created under the Safe Drinking Water and Toxic Enforcement Act of 1986, or Proposition 65, which mandates the state government maintain a list of naturally occurring or synthetic chemicals known to cause cancer or birth defects or other reproductive harm.


The OEHHA said it would add glyphosate as a chemical known to cause cancer in late March pending a lawsuit from Monsanto.

"Monsanto's challenge was unsuccessful in the trial court," the OEHHA said in a statement. "Although the case has been appealed, no stay of the listing has been granted. Therefore, glyphosate is being added to the Proposition 65 list on July 7."

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California's list must be updated at least once a year and includes more than 800 chemicals since it was first published in 1987.

The World Health Organization considers glyphosate as "probably carcinogenic." Countries that have banned glyphosate include Malta, Sri Lanka, the Netherlands and Argentina.

In Colombia, President Juan Manuel Santos' government stopped using glyphosate, which was used in aerial fumigations to destroy illegal coca plantations. Glyphosate was used to remove the leaves of the coca plant in Colombia for about 20 years.

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Monsanto has rejected previous studies identifying its product as a carcinogen.

"The allegation that glyphosate can cause cancer in humans is inconsistent with decades of comprehensive safety reviews by the leading regulatory authorities around the world," Monsanto previously said in a statement.

In March, documents unsealed in a federal court case seemed to show Monsanto ghostwrote studies on the herbicide Roundup for the U.S. Environmental Protection Agency.