Paraquat herbicide pulled from Australian market after new safety restrictions

Syngenta announced this week that it will stop selling paraquat in Australia, a decision that marks the effective end of the Swiss company's decades-long presence in the Australian herbicide market. The withdrawal comes after the Australian Pesticides and Veterinary Medicines Authority imposed new safety restrictions on the chemical in June, making the product what Syngenta's managing director David Van Ryswyk called "commercially unviable" to produce and distribute.

Paraquat is a potent herbicide that has already been banned in more than 70 countries worldwide, including every member state of the European Union since 2007. The chemical has long carried a shadow of scientific concern: it has been linked to Parkinson's disease in people exposed to it. Despite this global pattern of restriction, paraquat remained legal for agricultural use in Australia, where it was widely deployed across broad-acre cropping operations—grain farms, sugarcane plantations, and cotton fields relied on it as a tool for weed control.

The Australian regulator's June decision did not ban paraquat outright. Instead, it imposed a series of constraints designed to limit acute exposure and protect animal health. Backpack sprayers, which allow individual workers to apply the chemical directly, would be phased out. Users would be required to wear additional personal protective equipment. The maximum application rate per hectare would drop significantly. These measures, the APVMA determined, addressed the most dangerous exposure pathways without eliminating the product entirely. The authority's own assessment concluded that the weight of evidence did not demonstrate that paraquat exposure through approved agricultural uses increased Parkinson's disease risk—a position that diverges sharply from the scientific consensus in neurology.

Wes Thevathasan, a neurologist at the University of Melbourne, told the ABC last month that his field has reached "global consensus" on the paraquat-Parkinson's connection. Multiple epidemiological studies of real-world exposure, he explained, suggest that paraquat exposure increases Parkinson's disease risk by approximately threefold. This gap between regulatory assessment and clinical consensus underscores the complexity of chemical safety determinations, where different bodies weigh evidence differently.

Syngenta's decision to exit the market was not driven by the regulatory restrictions alone. The company had initially planned to continue supplying paraquat through a third-party manufacturer, absorbing the new compliance costs. But the combination of regulatory constraints and what Van Ryswyk described as an increasingly expensive and complex supply chain proved decisive. The economics no longer worked. Generic versions of paraquat, produced by other manufacturers, will remain available to Australian farmers—a detail that matters because it means the chemical itself is not disappearing from agricultural use, only Syngenta's branded product.

The withdrawal has created immediate concern in farming communities. Andrew Weidemann, a spokesperson for Grain Producers Australia, said the decision raises troubling questions about the future. Australia is a relatively small market in global terms, and when multinational agrochemical companies decide a market is no longer worth serving, it signals something about the economics of agriculture itself. Farmers worry not just about losing paraquat specifically, but about what the withdrawal suggests for other products. If companies cannot justify maintaining their product lines here, investment in new tools will dry up. At the same time, herbicide resistance is becoming an urgent problem on Australian farms—weeds are evolving immunity to existing chemicals, and growers need more options, not fewer. Syngenta's exit, whatever its commercial logic, leaves farmers with less choice at precisely the moment they need more.