The legalization of cannabis in Canada in 2018 set out to accomplish several things, including minimizing harm from use, establishing a safe and reliable supply chain, and enforcing public safety, education and protection. Since the introduction of the Cannabis Act and Regulations, the legal cannabis market has progressively been displacing illicit sources of cannabis (Statistics Canada 2023), though many cannabis users continue to access illicit cannabis (Rotermann 2020). Previous studies (OPP 2021, Eykelbosh 2021), including a study released by RPC (Botelho 2021), have demonstrated that cannabis products from illicit sources contain elevated levels of chemical and microbial contaminants and are grossly inaccurate with potency label claims. Moreover, a study from British Columbia (BC Cannabis Secretariat 2022) that looked at illicit cannabis flower and vape cartridges detected pesticides in all samples analyzed. A recent study by Health Canada (Gagnon 2023) also confirmed that illicit cannabis samples were plagued with pesticide contamination, with a 92% sample positivity rate.
With a rise in the popularity of vape products (Canadian Cannabis Survey 2022), continuing to understand the risks of cannabis vape products, particularly illicit vapes, is critical.
Due to the processing involved in making vape products and how they are packaged, there are additional concerns related to contamination from the use of solvents for extraction and the possibility of concentrating pesticides that may have been present in the flower material. Heavy metal contamination from processing or from vape cartridge heating elements/components and use of cutting agents are also a concern.
Methods
Whereas legal cannabis must be tested for contaminants, illicit cannabis does not need to follow Health Canada's Good Production Practices, greatly increasing the risk to cannabis users who choose to use illicit cannabis products.
Legal samples were obtained from Cannabis NB. Every sample was from a different licensed producer and was THC-dominant.
Illicit samples were legally obtained from Justice and Public Safety officers who transported the samples to the Research and Productivity Council (RPC) for testing. Although the focus of this study was on analysis of vape products, additional extract, flower, and edible samples were also provided.
Cannabinoid, pesticide, heavy metal, and residual solvent analyses were conducted using validated, ISO 17025-accredited methods. All illicit samples were tested for potency levels, including THC and THCA.
Results
Illicit Vape Cartridges: As seen in Table 3, half of the illicit vape samples did not have THC label claims. For the 9 samples that did, they ranged between 16% and 24% lower than claimed. Being outside the ± 15% variability limits that apply to legal product label claims, these products would not be compliant on the legal market.
Illicit Shatter: One of the three shatter samples tested (Illicit 20) had a THC label claim and fell just within the ± 15% variability limits that apply to legal product label claims.
Illicit Hash: The one illicit hash sample submitted for testing had a very low total THC content at 53 mg/g. It was also low in other cannabinoids with a total CBD of 17 mg/g and total CBN of 20 mg/g. Compared to hash products available on the legal market (with most products ranging from 290 to 500 mg/g total THC based on a search of hash products available on the Ontario Cannabis Store website on July 30, 2024), the THC content of this sample is notably low.
Illicit Infused Pre-Rolls: The two illicit infused pre-rolls had total THC concentrations of 202 and 220 mg/g, respectively. Compared to infused pre-rolls available on the legal market (most are between 300 to 450 mg/g total THC based on a search of THC-infused pre-roll products available on the Ontario Cannabis Store website on July 30, 2024), the THC content of these illicit samples is low.
Illicit Dried Flower: The three illicit flower samples tested had total THC values ranging between 144 and 188 mg/g.
Illicit Edibles (Chocolate, Gummy): The two illicit chocolate samples and the two illicit gummy samples had label claims that were 42% to 86% lower than the label claims. An illicit sample tested at 6.81 mg/gummy, which is more than seven times lower than the claimed 50 mg/gummy.
All legal samples had measured total THC concentrations within ± 15% of the label claims. One legal sample also had THCV listed on the label at 100 mg/g, with a measured value of 96.1 mg/g (-3.9% difference). Seven of the ten legal samples had CBD values reported as less than an indicated value. In these cases, a percent difference could not be calculated but the "less than" value was confirmed in six of seven samples. Legal 1 had a measured CBD value slightly above the claimed "< 5 mg/g". Another legal sample had a low CBD label claim (1.6 mg/g), with the measured value more than double the label claim. This product falls outside of the ± 15% variability limits for CBD displayed on a label for a cannabis extract product, as described in the Cannabis Regulations (SOR/2018-144).
For the legal vapes in this study, it was confirmed that pesticide residues were below the Health Canada limit LoQs. In contrast, a concerning 25 of 27 illicit samples tested had pesticide residues detected above the Health Canada limits (93% positivity rate). Across the 27 illicit samples tested for pesticides, 31 different pest control products were found above the Health Canada limits, with some testing orders of magnitude above the limit (Table 5). For example, Illicit 8 had myclobutanil present at 63 mg/kg, which is more than 3000 times above the Health Canada LoQ of 0.02 mg/kg for this pest control product.
Conclusions
Illicit products do not adhere to Good Production Practices and carry additional risks to consumers. Pesticide contamination was pervasive in illicit samples analyzed in this study, with a 93% positivity rate. Additionally, results for illicit cannabis samples seized in New Brunswick are consistent with results from previous studies on illicit cannabis in Ontario and British Columbia, highlighting that contaminated illicit cannabis and cannabis products can be found throughout Canada. THC label claims for illicit products continue to be inaccurate. In particular, the edibles tested in this study were well below label claims. However, some of these illicit edibles still contain THC quantities (per piece) that are well above the THC limit of 10 mg/package for edibles on the regulated market. Due to the possibility of higher THC, these illicit edibles pose additional risks from accidental ingestion, ingestion by a minor, or ingestion without knowing what dose is being consumed. Legal cannabis products are tested for hazardous contaminants and potency and must pass stringent testing criteria before being released for sale. Moreover, the regulated cannabis market allows for investigations and recalls if the safety of a legal cannabis product comes into question; this cannot occur for illicit products. Consuming regulated, legal cannabis greatly reduces risk for consumers compared to consuming illicit cannabis.