Court orders new review of popular weed killer

Health Canada failed to consider recent evidence on harmful impacts of glyphosate, federal court rules

June 23, 2025 (also see Update below) – Canada’s Pest Management Regulatory Agency (PMRA) has been ordered to conduct a new review of the pesticide glyphosate to take account of recent studies that raise concerns about adverse health and environmental effects associated with exposure to the popular weed killer.

The ruling from Federal Court on February 18, 2025 follows a lawsuit by the environmental law group Ecojustice on behalf of four non-governmental organizations – Friends of the Earth Canada, David Suzuki Foundation, Safe Food Matters, and Environmental Defence.

Products containing glyphosate received a Canadian regulatory stamp of approval back in 2017. The PMRA subsequently approved another glyphosate product in December 2022 on the basis of their 2017 review.

Ecojustice objected to the new rubber-stamp approval and appealed for an updated review of glyphosate-based herbicides, listing 61 new studies published since 2017 that identify specific health and environmental concerns around exposure to glyphosate.

In a statement, Ecojustice noted that “since the re-evaluation of glyphosate in 2017, scientific evidence has evolved. There are many emerging potential risks associated with glyphosate, including impacts on the microbiome, neurodegenerative and reproductive toxicity, adverse impacts to monarch butterflies, carcinogenicity, and ecological harm to freshwater ecosystems that Health Canada had not previously considered.”

The ruling by Justice Russel W. Zinn of Federal Court in British Columbia specifically says that the PMRA attitude of “trust us, we got it right” without actually examining current evidence is “unreasonable” and not sufficient as a rationale for new pesticide product approvals.

The judge gave the PMRA six months to conduct a detailed further review, including evidence on health and environmental risks identified in the 61 studies tabled by Ecojustice. Results are expected by the fall of 2025.

Updates and Further Notes

Spring 2026 – In August 2025, the PMRA reported that, following the court order, it had reviewed the studies listed by the plaintiffs in the lawsuit. Apparently, none of the 61 studies offered evidence that the PMRA regarded as requiring any change in the approval status of glyphosate. In the words of the Agency, “the existing reference values for glyphosate do not need to be revised, and the current risk assessment on file for the active ingredient glyphosate is valid.”

Some observers wonder if there is any level of scientific evidence that would prompt Canadian regulators to impose further restrictions on the use of glyphosate-containing pesticides.

Meanwhile in the United States, Bayer, the manufacturer of Roundup, which is much used in agriculture and whose principal active ingredient is glyphosate, is continuing to face legal pressure. The Lawsuit Information Center created by a US legal firm notes that more that 160,000 lawsuits have been brought by Americans claiming that their cancers (including non-Hodgkin lymphoma) were caused by exposure to Roundup. The site reports that Bayer has paid out nearly $11-billion to date to settle some 100,000 of these suits. And in February 2026, Bayer offered a further $7.25-billion to settle the 60-65,000 lawsuits that remain unresolved. A US judge is to rule on the proposed arrangement in July 2026.

Back in Canada, under current regulation, glyphosate is scheduled for formal re-evaluation in 2032.

June 25, 2026 (Update on US lawsuits) – Some plaintiffs in the United States had sued Bayer on the grounds (in part) that the label on Roundup products did not include a warning on cancer risk. In April, 2026 the US Supreme Court heard Bayer’s appeal of a case involving a Missouri man who claimed that his non-Hodgkin lymphoma was caused by exposure to Roundup and that the company had failed to warn of cancer risks associated with the use of the product. On June 25, 2026 the Supreme Court ruled that, since the Environmental Protection Agency, which regulates pesticides in the United States, did not require a cancer warning on Roundup product labels, the company would have violated US federal law if it had placed such a warning on the label in the absence of an EPA directive. As a result, Bayer cannot be found liable solely on the grounds that it failed to include on Roundup product labels a warning of a potential cancer risk. As noted by the Lawsuit Information Centre, despite this legal setback there are still thousands of pending lawsuits that do not turn on the question of a label warning.