How Canada Keeps Toxic Pesticides on the Market

Canada’s proposed pesticide reforms move in the wrong direction.

The following essay was published on May 22 as an OpEd in The Hill Times, a widely read independent newspaper in Ottawa that covers Parliament, federal politics, and public policy. It comes at a moment when Canada is beginning to rethink how it regulates toxic chemicals and pesticides.

While the United States allows the sale of chlorpyrifos and paraquat, Canada banned chlorpyrifos in 2023 and discontinued paraquat shortly afterward. These decisions reflect a growing recognition that some chemicals once considered acceptable carry costs that are measured not only in crop yields, but in children’s brains, chronic disease, and the long-term health of communities.

For more than half a century, pesticides like chlorpyrifos and paraquat were used in Canada under regulations that were supposed to protect human health. Yet one is now known to damage children’s brains, while the other increases the risk of Parkinson’s disease. If that happened under stronger oversight, why would weakening pesticide regulation now make Canadians safer?

Prime Minister Mark Carney’s proposed overhaul of Canada’s pesticide law is being framed as “modernization.” In reality, much of it would weaken public-health protections in favour of short-term economic considerations. The proposed reforms would allow cabinet to overrule the health minister on pesticide approvals, delay reviews of harmful products for up to six years, eliminate mandatory re-evaluations, and shift the purpose of the law away from precautionary protection toward balancing health against economic and food-security concerns.

The problem is that Canada’s existing regulatory framework has already failed repeatedly to protect the public from chemicals later shown to be dangerous.

Chlorpyrifos was used for decades before it was finally banned in Canada, despite evidence that exposure during pregnancy lowered children’s IQ, increased ADHD, and altered brain development. Even more troubling, scientists later discovered that the original industry study used to support approval relied on the wrong statistical test. Had the correct analysis been used, chlorpyrifos may never have been approved in the first place. Yet regulators—including Canada’s Pest Management Regulatory Agency (PMRA)—failed to detect the error for decades.

The story of paraquat is equally troubling. Industry scientists knew as early as the 1960s that paraquat damaged the nervous system. Decades later, studies in farmers and rural communities showed higher rates of Parkinson’s disease among people exposed to the herbicide. Yet paraquat remained available for use in Canada for generations under the same regulatory system now being described as overly burdensome.

Canada has seen this pattern before. University of Saskatchewan biologist Christy Morrissey found widespread neonicotinoid contamination in prairie wetlands and warned about ecological harm to insects and birds. The response was not rapid precaution, but years of industry pushback and regulatory delay.

This is why modernization should mean more rigorous and independent testing, not less oversight.

What is striking about these proposed reforms is that they place immediate economic considerations above health costs that are harder to measure in quarterly budgets but very real in people’s lives. The government speaks about reducing regulatory burden, but says far less about the burden carried by families living with cancer, Parkinson’s disease, children with learning disabilities, overwhelmed schools, rising health-care costs, lost productivity, and years of preventable suffering.

I am not opposed to considering economic impacts. Farmers need workable tools and stable food systems. But farmers and rural communities also deserve regulations strong enough to protect them from chemicals that may damage health over years of exposure.

Industry will argue that pesticides are already rigorously tested. But that assumes the existing regulatory framework—which relies heavily on industry-funded animal studies and limited pre-market testing—can detect subtle long-term harms to brain development, fertility, and chronic disease before millions of people are exposed.

It cannot. Chlorpyrifos and paraquat are stark reminders of that failure.

This is not simply a story about past regulatory failures. Even as federal agencies move toward phasing out PFAS “forever chemicals,” PMRA has continued approving new PFAS pesticides that degrade into highly persistent fluorinated compounds. The contradiction is difficult to ignore: one arm of government warns Canadians about PFAS while another continues approving them for use on food crops.

If Canada truly wants to modernize pesticide regulation, it should strengthen PMRA’s mandate to protect Canadians from inadequately tested chemicals; require more independent studies before approval; make all industry-funded studies publicly available for independent scrutiny; restrict industry influence on advisory panels; require regular re-evaluations as new science emerges; and expand testing to assess how pesticides disrupt hormonal, neurological, immune, and metabolic systems in humans, wildlife, pollinators, fish, and the soil microbiome itself.

A modern regulatory system would also evaluate real-world chemical mixtures rather than isolated chemicals, account for cumulative exposures over a lifetime, strengthen post-market surveillance, and place far greater weight on independent public-health research instead of relying primarily on proprietary industry studies.

That would be modernization. What is currently being proposed is something else entirely.