A key glyphosate safety study has been retracted after 25 years, raising new calls for Health Canada to revisit its approval of the widely used herbicide.
Glyphosate Study Pulled, Canada Faces Renewed Safety Demands
Retraction of Landmark Paper Raises Alarm
A 25-year-old study long cited to support the safety of glyphosate — the active ingredient in Roundup — has been withdrawn by Regulatory Toxicology and Pharmacology. The journal cited U.S. litigation documents suggesting Monsanto employees contributed to the study without acknowledgement and that conclusions relied heavily on unpublished company data. The decision has sparked concern among environmental groups who view the paper as foundational to global regulatory decisions.
Health Canada Maintains Its Existing Position
Despite the retraction, Health Canada says its approval of glyphosate remains unchanged. The department noted that the withdrawn review was only one of many sources assessed during its 2017 re-evaluation, which examined more than 1,300 scientific studies. Officials said the chemical was found “unlikely to pose a human cancer risk,” and the approval of glyphosate-based herbicides through 2032 still stands.
Advocates Push for Immediate Federal Action
Environmental organizations, including Friends of the Earth Canada, are urging Health Canada to impose a moratorium on glyphosate sales and launch an expedited special review. CEO Beatrice Olivastri said the retraction “landed like a bomb,” warning that long-standing safety determinations may need to be reconsidered. Environmental Defence echoed concerns, pointing to emerging science suggesting links to a range of health harms.
Widespread Use Across Canadian Agriculture
Glyphosate use continues to rise, with approximately 50 million kilograms sold in Canada each year, making it the country’s most heavily applied pesticide. It is used on crops such as canola and wheat and deployed by forestry operations to manage competing vegetation. More than 160 glyphosate-based products remain authorized for sale in Canada, and the herbicide has been in commercial use since the 1970s.
Industry Rejects Concerns About Safety
Bayer, which acquired Monsanto, said in a statement that it “firmly stands behind the safety” of glyphosate products, emphasizing decades of regulatory approvals worldwide. Monsanto, in a separate statement, acknowledged involvement in the retracted study but said it did not rise to the level of authorship and that researchers maintained control of the manuscript.
Scientific Community Calls for Review of Latest Evidence
Bruce Lanphear, a professor at Simon Fraser University, said ghostwriting has historically been “part of the playbook” in the pesticide sector. He noted that while Health Canada and the U.S. Environmental Protection Agency have concluded glyphosate is safe, the International Agency for Research on Cancer classified it as “probably carcinogenic to humans” in 2015. Lanphear argued that the retraction strengthens the case for re-evaluating the current science, especially with most Canadians exposed to traces of the herbicide.
