In a significant victory in the fight against toxics, environmental and health groups in Canada have successfully challenged the federal government’s renewal of a glyphosate product in court.
In a February 2025 ruling, the Federal Court found that Health Canada’s 2022 decision to re-approve the glyphosate-based herbicide “Mad Dog Plus” was not substantiated by scientific assessment. This is because the “acceptable risk” of glyphosate was last assessed by Health Canada in 2017, and much new science on the risks has come out since.
The Court set aside Health Canada’s re-approval of the product and has given the department six months to assess the latest science.
Glyphosate is the most widely used herbicide in Canada by a large margin. The glyphosate product “Mad Dog Plus” is used in both agriculture and forestry.
Two Brazilian studies – the first of their kind – found that glyphosate exposure was robustly associated with increased infant mortality and cancer deaths in children.
The court case was brought forward by Friends of the Earth Canada, Safe Food Matters, the David Suzuki Foundation, and Environmental Defence Canada, represented by Ecojustice lawyers. The groups are challenging the Pest Management Regulatory Agency (PMRA) of Health Canada to be transparent about the science it uses in assessing the “acceptable risk” of active ingredients in pesticides and to ensure it uses current research findings.
After the launch of the case, documents uncovered through Access to Information revealed that PMRA planned to review new glyphosate science in 2022 but then renewed approvals without completing this review. That planned review was not disclosed to the Court or the public.
Glyphosate use increased dramatically in North and South America with the introduction of genetically modified glyphosate-tolerant crops, designed to be used with the specific agrochemicals. Herbicide sales in Canada have increased by 243% since the introduction of GM crops.
Glyphosate’s harms: new evidence
The court decision in Canada comes as three new large-scale, population-level studies from the US and Brazil show harm to infants from glyphosate, from both local and downstream exposure associated with growing GM corn and soy.
The US study assessed areas where GM crops are grown and found that infants in areas where glyphosate use is common were born slightly earlier and underweight.1 The authors say, “Our results suggest the introduction of GM seeds and glyphosate significantly reduced average birthweight and gestational length.” The study analyzed birth data from more than 10 million babies born between 1990 and 2013 and compared it with estimated amounts of glyphosate and other agrochemicals sprayed.
The two Brazilian studies – the first of their kind – found that glyphosate exposure, driven by the expansion of GM seeds and transported through rivers, was robustly associated with increased infant mortality and cancer deaths in children.2,3 Brazil uses nearly twice the amount of glyphosate per hectare on cropland than the US. Glyphosate dominates intensive GM soy and corn production and is also used on vast eucalyptus tree plantations (for pulp and paper), with the giant Brazilian pulp company Suzano proposing to introduce GM glyphosate-resistant eucalyptus trees.
The US study authors state, “The mounting evidence of the negative health externalities associated with the rollout of GM crops and the ensuing glyphosate intensification warrant new policy discussions about informed, efficient, and equitable regulation of these technologies.”
Lucy Sharratt is Coordinator of the Canadian Biotechnology Action Network (CBAN), a project on the shared platform of the MakeWay Charitable Society.
- E. Reynier, & E. Rubin, Glyphosate exposure and GM seed rollout unequally reduced perinatal health (2025)
- M. E. Skidmore et al, Agricultural intensification and childhood cancer in Brazil, PNAS 2023 Vol. 120 No. 45 e2306003120
- M. Dias et al, Down the River: Glyphosate Use in Agriculture and Birth Outcomes of Surrounding Populations, The Review of Economic Studies, Volume 90, Issue 6, November 2023, Pages 2943–2981
