California passes law ordering review of paraquat weed killer

By Carey Gillam

Efforts by some California lawmakers to ban the controversial weed killing chemical paraquat ended this week with passage of a law that keeps the chemical in use but requires a reevaluation by regulators within the next five years.

Backers of a ban cited scientific evidence linking paraquat to a range of health problems, including the incurable brain disease known as Parkinson’s, as a key reason to outlaw paraquat use in the state.

The California State Assembly earlier this year had approved what was referred to as a “moratorium” on paraquat that would have taken effect in January 2026 and provided for a process that have would have given state regulators an opportunity to reevaluate paraquat and potentially reapprove the chemical with or without new restrictions.

But state Senate amendments killed any moratorium or restriction on use. The bill, as passed, now only requires state pesticide regulators to complete a reevaluation of paraquat by January 2029.

California Assemblymember Laura Friedman said the fact that the legislature passed requirements for a regulatory reevaluation is still a win.

“With the mounting medical evidence indicating that paraquat is simply too toxic to remain in wide use, I am very confident that [state regulators] will not only do a thorough re-evaluation of paraquat, but either ban it outright or place greater restrictions on its use,” Friedman said in a statement.