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California to ban chlorpyrifos

State begins process to cancel all uses of the pesticide to protect farmworkers, children

by Britt E. Erickson
May 9, 2019 | A version of this story appeared in Volume 97, Issue 19


California is slated to become the third US state to ban the organophosphate insecticide chlorpyrifos, following action in Hawaii and New York. California’s Department of Pesticide Regulation (DPR) has initiated the process of canceling all uses of the pesticide in the state to protect farmworkers, children, and the environment, the California Environmental Protection Agency (CalEPA) announced on May 8.

Chemical structure of chlorpyrifos.

Chlorpyrifos is associated with neurodevelopmental problems and impaired brain function in children.

Earlier this year, California listed chlorpyrifos as a toxic air contaminant. The state is therefore required to establish measures to protect farmworkers and other people who are likely to be exposed to the pesticide. The state determined that sufficient control measures are not feasible, so it is now proceeding with a ban on the chemical. The process is likely to take up to 2 years, according to the CalEPA.

“California’s action to cancel the registration of chlorpyrifos is needed to prevent the significant harm this pesticide causes children, farm workers and vulnerable communities,” CalEPA secretary Jared Blumenfeld says in the statement. “This action also represents a historic opportunity for California to develop a new framework for alternative pest management practices.”

Chlorpyrifos is used to combat pests on numerous crops, including almonds, citrus, and grapes. In California, use of the pesticide declined by more than 50% from 2005 to 2016, as farmers moved to safer alternatives, such as biological controls, according to the state’s DPR.

Environmental and consumer advocacy groups are welcoming California’s announcement. “We are thrilled that California has taken the lead in putting the interests of our children ahead of chemical company profits,” Rebecca Spector, West Coast director at the Center for Food Safety, says in a statement. “This is a huge win for children, consumers, and farmers across the State.”

Pesticide manufacturer Corteva Agriscience, the agriculture division of DowDuPont, is disappointed in the decision, claiming chlorpyrifos is an important tool for farmers. The company sells the pesticide in the US under the brands Dursban and Lorsban. “We are evaluating all options to challenge this proposal,” Corteva spokesperson Gregg Schmidt says.

The US Environmental Protection Agency is under a court order to make a decision about whether to ban chlorpyrifos by mid-July. The agency proposed to do so in 2015 and 2016.



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