OMAHA (DTN) -- California regulators are moving to cancel chlorpyrifos registrations in the latest of a series of moves targeting a key insecticide used by farmers.
The California Environmental Protection Agency announced in a news release Wednesday its decision came following a state scientific review panel's findings that the pesticide causes "serious health effects in children and other sensitive populations at lower levels of exposure than previously understood."
Chlorpyrifos use in California has been on the decline since 2005, according to the state's department of pesticides registration. About 2 million pounds of the insecticide was used in 2005, but that fell to about 900,000 pounds in 2016.
"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 said in a press statement. "This action also represents a historic opportunity for California to develop a new framework for alternative pest management practices."
On a national level, the U.S. EPA has until July 18 to address objections to its 2007 decision to reject a petition asking the agency to ban chlorpyrifos as a result of an order issued by the U.S. Court of Appeals for the Ninth Circuit in San Francisco.
On Nov. 10, 2016, then-President Barack Obama's EPA announced plans to ban chlorpyrifos. That was reversed by the Trump administration.
In August 2018, the Ninth Circuit ordered EPA to ban the use of chlorpyrifos. That was reversed by the full Ninth Circuit as a result of an en banc hearing.
In April 2019, California formally listed chlorpyrifos as a "toxic air contaminant." State law defines that as "an air pollutant which may cause or contribute to an increase in mortality or an increase in serious illness, or which may pose a present or potential hazard to human health."
The California Department of Pesticide Regulation is required to develop control measures to protect human health.
In California, chlorpyrifos is used to control pests on alfalfa, almonds, citrus, cotton, grapes and walnuts.
The state said in a news release Wednesday it plans to convene a working group to identify alternatives to chlorpyrifos.
In 2015, the state designated chlorpyrifos as a "restricted material" that requires a permit for its application.
Chlorpyrifos is the main ingredient in what was Dow AgroScience's -- now Corteva Agriscience's -- Lorsban insecticide, which also targets pests such as soybean aphids, spider mites and corn rootworm.
Corteva did not respond to DTN's request for comment.
The national legal pursuit began in 2007 when the Pesticide Action Network North America and the Natural Resources Defense Council petitioned EPA to cancel chlorpyrifos registrations.
A Columbia Center for Children's Environmental Health study has been widely used as support for a ban, despite divergent scientific views among EPA scientific review panels, and former President Barack Obama's administration's USDA questioning the study and its data.
A 2016 EPA scientific advisory panel indicated some members of that panel said they had difficulty assessing the study, because the raw data from the study was not made available.
On July 30, 2018, the California Department of Pesticide Regulation released a scientific assessment that concluded chlorpyrifos should be listed as a toxic air contaminant in the state based on evidence of its neurological effects and exposure risks.
Todd Neeley can be reached at email@example.com
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