California to List Glyphosate, Pesticides as Carcinogens

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By Carolyn Whetzel

Sept. 4 — California's Office of Environmental Health Hazard Assessment plans to identify the herbicide glyphosate, also known as Roundup, and three pesticides as carcinogens under Proposition 65.

Under Proposition 65, businesses must provide consumer warnings on produce labels when exposing the public to unsafe levels of listed chemicals linked to cancer or reproductive harm.

Glyphosate (CAS No. 1071-83-6), tetrachlorvinphos (CAS No. 22248-79-9), parathion (CAS No. 56-38-2) and malathion (CAS No. 121-75-5) are being listed under the state's landmark Safe Drinking Water and Toxic Enforcement Act of 1986 via an administrative process, OEHHA said.

The law's “labor code mechanism” allows listing of chemicals already linked to cancer by the International Agency for Research on Cancer.

A document IARC published on its website earlier this year concluded malathion and glyphosate are probably carcinogenic to humans and classified the other two pesticides are possible carcinogens, OEHHA said.

“California's taking an important step toward protecting people and wildlife from this toxic pesticide,” Nathan Donley, a scientist at the Center for Biological Diversity, said of the proposed listing of glyphosate Sept. 4. “More than 250 million pounds of glyphosate are used each in the United States, and the science is clear that it's a threat to public health and countless wildlife species.”

OEHHA is accepting comment on the proposed listings through Oct. 5.

To contact the reporter on this story: Carolyn Whetzel in Los Angeles at

To contact the editor responsible for this story: Larry Pearl at

Information on the proposed listings is available at