The Cannabis Data Gathering Program (the Program), launched in 2023 by Health Canada's Cannabis Laboratory, helps Health Canada collect information on the composition and quality of cannabis products available in Canada. The Program projects provide new data on cannabis where information may be limited, providing new evidence about potential risks and emerging trends. This strengthens Health Canada's ability to regulate the cannabis industry and inform Canadians about the health and safety risks associated with cannabis use. Information from the Program projects will also guide future regulatory, inspection, surveillance and outreach efforts.
The main objective of this first project under the Program was to generate baseline data on total Delta-9-tetrahydrocannabinol (THC) levels, heavy metals, mycotoxins, pesticides and microbial contaminants in dried cannabis, both legal and illegal, available on the Canadian market. In this initial survey, 100 dried cannabis samples (50 legal and 50 illegal) were tested, revealing the following trends:
- Total THC levels: Among legal products, a significant proportion showed total THC levels below their declared amount, with 48% having total THC levels under 80% of their label claim. None of the illegal cannabis products seized by law enforcement included label information when submitted to the laboratory. Analysis revealed wide variability in total THC potency, ranging from less than 100 mg/g to more than 250 mg/g.
- Heavy metals: All samples collected were analyzed for a suite of 18 metals. Regarding the 4 most commonly tested metals (arsenic, cadmium, lead and mercury), only one illegal sample had arsenic levels above the United States Pharmacopeia (USP) tolerance limit set for inhalation. Overall, however, these metals were present in a significantly higher proportion of the illegal samples. On the other hand, copper, molybdenum and nickel were found in a large proportion of both legal and illegal samples, some in concentrations exceeding tolerance limits.
- Mycotoxins: None of the 6 mycotoxins tested were found in legal products. In contrast, 6 illegal samples tested positive for either ochratoxin A or deoxynivalenol (DON).
- Pesticides: Only two legal products showed trace levels (0.01 parts per million [ppm]) of pesticides out of over 300 pesticide residues tested. In comparison, 94% of illegal samples had multiple pesticides, averaging 3.4 pesticides per sample, with a total of 24 different pesticides identified, some at very high levels. The most commonly found pesticides in illegal samples were myclobutanil and paclobutrazol.
- Microbial contaminants: Although a few legal products tested positive for microbial contaminants, illegal cannabis products were found to have significantly higher levels of microbial contamination when compared to cannabis obtained from the legal market, often exceeding European Pharmacopeia (Ph. Eur.) limits. These included opportunistic pathogens such as Enterobacter cloacae and bacteria associated with respiratory infections such as Klebsiella spp. and Pseudomonas aeruginosa.
This survey represents an important step in understanding the composition of dried cannabis available in Canada. By analyzing dried cannabis samples, Health Canada has generated baseline data on total THC levels, heavy metals, mycotoxins, pesticide residues and microbial contaminants, showing significant differences between the legal and illegal markets.
The findings underscore the importance of ongoing data collection to identify trends, inform regulatory decisions and improve product safety. Future projects under the Program will build on these results, enhancing Health Canada's ability to protect public health, guide regulatory actions, and support Canadians in making informed choices about cannabis use.
Read more at Government of Canada