California has become the first state to phase out paraquat-dichloride, one of agriculture’s most toxic weedkillers, after manufacturers voluntarily cancelled their registrations to sell the herbicide in-state. The Environmental Working Group (EWG) applauded the move on August 10, signaling a rare win for farmworker safety advocates and public-health groups fighting the pesticide’s continued use.
Paraquat—a fast-acting contact herbicide used on row crops, tree nuts, and pastureland—has been under scrutiny for decades. Epidemiological studies have linked repeated exposure to Parkinson’s disease and other neurological damage, with farmworkers facing the heaviest cumulative risk. The chemical is already banned in the European Union, Brazil, and China, yet it remained legal across most of the U.S. agricultural heartland until now.
The California Department of Pesticide Regulation’s announcement came without fanfare, but it represents a hard-won shift in how the state regulates ag chemicals. Manufacturers made the call to withdraw paraquat rather than fight California’s regulatory push—a calculation rooted in simple economics. The state’s $50-billion agricultural market is too large to ignore, and the reputational and liability costs of defending a neurotoxic pesticide no longer pencil out.
Farmworkers and rural communities bear the real cost. Paraquat is absorbed through skin and lungs, and there is no antidote. In cases of acute poisoning, exposure can cause fatal pulmonary edema within days. Chronic exposure at lower levels carries the Parkinson’s risk, which can take decades to manifest. By then, the causal link is blurred, and farmworkers struggle to prove occupational causation in court.
The phase-out won’t happen overnight. Existing inventory can continue to be used and sold through a grace period, meaning paraquat will remain in California fields through at least 2027. Growers who have relied on the herbicide for decades—particularly in cotton, alfalfa, and tree-crop operations—will need to switch to alternatives. Some have already begun. Others are lobbying for extended timelines.
What’s next is less certain. Federal regulators at the EPA have resisted pressure to ban paraquat nationally, despite years of advocacy from the United Farm Workers and other labor groups. The current administration has signaled skepticism of new ag-chemical restrictions, prioritizing industry stability over precautionary health measures. California’s move, however, shifts the pressure: other states with strong agricultural lobbies—like Illinois and Iowa—may face constituent pushback if they continue tolerating a chemical their western peers have abandoned.
The real test will be what happens in the gap. Between now and full phase-out, growers desperate to clear weeds in a tight margin environment may hoard remaining supplies or ship in from other states where paraquat remains legal. Enforcement and farmer education matter as much as the ban itself.
For farmworkers, the news is cautiously welcome. But the struggle over paraquat mirrors a larger crisis in agricultural toxicology: the EPA’s regulatory apparatus moves slowly, chemical manufacturers have deep resources to litigate, and farmworkers—often undocumented or linguistically isolated—lack the political power to force action at the federal level. California’s phase-out is a blueprint for pressure, but it also highlights how fragmented U.S. pesticide policy remains. A chemical deemed too dangerous for California should not be legal to spray in Iowa.
