California lawmakers have approved a bill that could help strengthen regulations on the use of paraquat, a powerful weedkiller associated with Parkinson’s disease and other serious health issues.
Assembly Bill 1963 was introduced in January by Assemblymember Laura Friedman (D-Glendale), and originally sought to sunset the use of paraquat in California beginning in January 2026.
However, the final legislation has been amended so that it now will require the California Department of Pesticide Regulation to complete a reevaluation of the herbicide by Jan. 1, 2029, and determine whether to retain, cancel or suspend its registration, or to create new restrictions. The bill passed the Senate 23 to 8 and now awaits a signature from Gov. Gavin Newsom.
Paraquat is banned in more than 60 countries. Many environmental and advocacy groups had been hoping for an outright ban in California, but said the bill still marks a step forward by fast-tracking its safety review — a process that can sometimes take decades.
“We are encouraged by the progress being made in California setting the example for other states to act when it comes to evaluating the safety and toxicity of chemicals with long term neurological and other health implications,” read a statement from Julia Pitcher, director of state government relations for the Michael J. Fox Foundation for Parkinson’s Research. “We strongly urge the passage of this legislation and look forward to Governor Newsom signing it into law soon.”
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The U.S. Environmental Protection Agency describes paraquat as highly toxic — noting that “one sip can kill” — yet California remains one of the nation’s top users of the chemical. The state sprays millions of pounds annually on crops such as almonds, grapes and cotton.
An Environmental Working Group report published earlier this year found that the state’s farmworkers and low-income Latino people, in particular, are disproportionately exposed to paraquat in their communities, with more than 5.3 million pounds sprayed in Kern County alone between 2017 and 2021.
The bill faced opposition from a coalition of opponents including pesticide manufacturers, chemical industry trade associations and agriculture trade organizations.
By the time it wound its way through the legislature, including the Senate Agriculture Committee, it had lost much of its teeth, said Bill Allayaud, California director of government affairs with EWG.
“It’s still a good bill, because without this, DPR probably wouldn’t do anything,” he said. “Hopefully the governor will sign it and agree that this is at the top of the list for things we don’t want people exposed to, especially farmworkers.”
Assembly Bill 1963 would sundown the use of the herbicide paraquat, which has been linked to Parkinson’s disease and other health issues, beginning in January 2026.
Paraquat has been the subject of thousands of lawsuits from people seeking damages related to exposure to the product, including people who say it has given them Parkinson’s disease, a neurodegenerative disorder that affects movement.
The bill’s legislative analysis notes that at least 10 epidemiological studies have linked paraquat exposure to Parkinson’s disease, including a 2019 meta-analysis of 13 studies that found exposure to the herbicide was associated with a 1.64-fold increase in the risk of the disease.
Other studies have found no clear link, however, and the product’s manufacturers continue to reject any claims of a connection.
In a statement, Friedman said AB 1963 will have “very real results.”
“I’m happy with where the bill landed,” Friedman said. “We never thought we’d get a full ban through the Legislature. But we had to push as hard as we could.”
She noted that the Legislature provided the Department of Pesticide Regulation with additional funding this year with a requirement that the agency do more reevaluations of toxic chemicals.
“I have full confidence, that should AB 1963 get signed into law, that DPR will do a thorough reevaluation of paraquat, and either ban it outright, or place greater restrictions on its use,” Friedman said.
The Environmental Protection Agency issued an emergency ban on a common weed killer, DCPA or Dacthal, over concerns about the health risks for fetuses.
Advocacy groups remain committed to seeing the chemical controlled.
The EWG this week launched a campaign with the Michael J. Fox Foundation urging President Biden and the EPA to ban paraquat nationwide. The federal agency will have until Jan. 17 to make a decision.
There is some reason for optimism: The EPA last month issued a rare emergency order to stop the use of another weedkiller, dachthal, that poses a significant risk to fetuses.
