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More Pesticides in Illicit Cannabis

Illicit cannabis is more likely to contain pesticides than legal cannabis according to a new study conducted by researchers at Health Canada’s pesticide lab.


Canadian licensed producers are required to demonstrate that no unauthorized pesticides are used to treat cannabis or have contaminated it. The study aimed to confirm if the implementation of the Cannabis Act is providing safer licensed products to Canadians in comparison to those from the illicit market.

Although the legal market has been gaining ground in Canada since legalization, according to a 2021 Canadian Cannabis Survey, up to 13% of Canadians still report consuming illicit cannabis almost exclusively.


Researchers took samples of dried cannabis flower from the legal and illicit markets and analyzed them for pesticide residue.

The 36 licensed samples were purchased in 2021 from the Ontario Cannabis Store from licensed holders located in all five Canadian regions (British Columbia, Prairies, Ontario, Quebec, and Atlantic). The 24 illicit cannabis samples were obtained from seizures by law enforcement officers across the country and submitted to Health Canada for lab testing in 2021.


The results found a 6% pesticides positivity rate in legal products with only two pesticide residues detected.

Despite a 6% positivity rate, the licensed Canadian cannabis sector has greatly improved with respect to the presence of pesticides since the 2019 mandatory cannabis testing for pesticide active ingredients requirements. Prior to 2019, the positivity rate for the legal market was 30%.

In comparison, illicit products has a 92% sample positivity rate covering 23 unique pesticide active ingredients with 3.7 different pesticides identified on average per sample.

Tags: cannabis study (4), cannabis testing (7), Health Canada (64), illicit cannabis (7), pesticides (1), unauthorized pesticides (2)