A new study conducted in New Brunswick reveals high levels of chemical contaminants in illicit cannabis vape cartridges, including high levels of pesticide contamination.
The study, released by RPC Labs, an analytical testing lab, looked at chemical analysis of cannabis vape carts, extracts like hash and shatter, dried cannabis flower, and edibles. RPC is New Brunswick’s provincial research organization.
Results also showed THC levels in illicit products much lower than the labelled amount, with edibles and vapes being from 16% to 86% less THC than the packaging claimed.
They tested 31 illicit cannabis samples (18 vape cartridges, three packages of shatter, one of hash, and one infused pre-roll, plus three flower samples and four edible samples). RPC also tested 10 legal cannabis vape cartridges, which were analyzed for total THC and chemical contaminants (pesticides, heavy metals, residual solvents).
The samples of unregulated products were from materials seized by law enforcement in New Brunswick in early 2024 and then provided to RPC. The 10 legal vapes were sourced from CannabisNB and represented 10 different products from different producers.
Andrien Rackov, the lead author of the study and the director of research and controlled substances at RPC (Research & Productivity Council), says one of the goals with this kind of research is to provide a clearer picture of what is in products in the illicit market across Canada.
“You really don’t know what you’re getting and these products are not being screened for contaminants.”
Andrien Rackov, Research & Productivity Council
This is the second time RPC has conducted this kind of sampling on products seized from the illicit market, the first in 2021 primarily looked at flower and edibles. He says this time they wanted to look at concentrates, especially vape pens in the illicit market.
“This is the importance of continued studies,” Rackov tells StratCann. “The more studies done over time, you can take all of that data together. It starts to paint a pretty clear picture, and we see this as adding to that picture.”
“The intent here is very much for people to have a better understanding of the reality of the illicit cannabis market,” he adds. “You really don’t know what you’re getting and these products are not being screened for contaminants.”
While there have been isolated instances of contaminants found in products from the legal market, Rackov also points out that these are more likely to be discovered through active product testing in the legal supply chains, and can come with corrective actions like product recalls and public notices. With illegal products, consumers have no way to hold producers accountable.
“If there are any issues that pop up with legal cannabis, we actually have mechanisms for doing recalls, investigations, whether it’s cannabis or the salad you buy at the grocery store, you can actually try to do something about it as opposed to illicit products where you’re not going to know what you’re getting.”
Although the sampling RPC has done has been on products seized from the unlicensed market in New Brunswick, he also argues that similar testing in other provinces helps show these results are not isolated incidents, but rather reflect the current state of Canada’s illegal cannabis market.
Alarming levels of chemical contaminants
The results show not only “alarming” levels of chemical contaminants in illicit cannabis vape cartridges and extracts, including a 93% positivity rate for pesticide contamination, but also revealed that the illicit vapes and edibles were often well below their stated THC label claims.
While all legal vape samples had THC label claims that were compliant with Health Canada regulations that allow for a 15% discrepancy in label claims, 10 of the 11 illicit cannabis vapes that had THC label claims were 16% to 24% lower than the THC listed on the label or package.
In addition, all four edible products from the illicit market included in the test were from 42% to 86% below the label claim for THC levels. One gummy that was advertised as having 50 mg THC actually contained only 6.81 mg THC. A cannabis chocolate from the illicit market that claimed to have had 600 mg THC per piece was actually 272 mg THC per piece.
None of the legal vape samples had pesticides detected at the Health Canada limits, but 25 of 27 of the illicit cannabis extracts and cannabis flower (which includes vapes) products tested had pesticides detected above Health Canada limits, in some cases three orders of magnitude above the limit.
Samples collected from the illicit market included 18 vape cartridges, three samples of shatter, one of hash, and two infused pre-rolls. The dried flower samples were one pre-roll and two dried flower, while the edibles were from two chocolates and two gummies.
The gap between label claims and testing results
Of the 10 legal vape carts tested, label claims for THC were all less than 5% difference, while one cart was found to have 109.4% more CBD than advertised (1.6 mg/g label claim vs 3.35 mg/g actual).
Mylcobutinil, commonly used as a fungicide to deal with things such as powdery mildew, was found in 22 of the 27 samples from the illicit market. RPC found 31 different pest control products above Health Canada’s allowable limits. One sample showed myclobutanil present at 63 mg/kg – more than 3,000 times above the Health Canada limit of 0.02 mg/kg for this pest control product.
Boscalid, another fungicide often used for bud rot, was found in 17 samples. Acequinocyl, an insecticide, was found in 16 of the illicit market samples. Sixteen samples had five or more pesticides detected above Health Canada’s allowable limits, with one vape cart having 22 pesticides above Health Canada limits. Only two samples from the illicit market, both shatter, had no detectable amounts of pesticides.
Heavy metals and elemental impurities
In addition to pesticides and cannabinoid levels, RPC also tested samples (except the edibles) for elemental impurities, including arsenic, cadmium, lead, and mercury.
All 10 legal cannabis vape carts showed these heavy metals at acceptable levels except for one with lead detected at 1.49 µg/g. The research report notes that this lead may have leached into the cannabis vape distillate from the heating element in the vape cartridge or other packaging components.
All vape products were tested as they were in the packaging, rather than following the heating and cooling cycle of consumer use.
Of the 27 illicit samples tested for heavy metals, seven had values above the allowable reporting limits. Only one of the illicit vape carts had heavy metals over allowable limits (0.17 µg/g), but the hash, both infused pre-rolls, both dried flower samples, and one pre-roll all had levels of at least one heavy metal well over the allowable detectable limit.
The hash was found to have higher levels of arsenic, cadmium, and lead, while the infused pre-rolls were found to have cadmium, lead, and mercury.
A need for continued research
Stability studies, extractable/leachable studies, and screening of components used for making vape cartridges would be useful for understanding more about the source of metal contamination.
Funding for this study was obtained from the Cannabis Education and Awareness Fund (Government of New Brunswick). The New Brunswick Department of Justice and Public Safety legally provided the Illicit samples to RPC Labs.
Similar research results have come from other organizations working with provincial governments in recent years showing high levels of pesticides and inaccurate labelling of products from the unregulated and illicit market.
A 2021 report from the New Brunswick Research and Productivity Council found THC levels in the black market were much lower than advertised and also found high levels of moulds, heavy metals, and pesticides.
A 2022 study from the National Research Council on behalf of the OCS and Ontario Provincial Police showed that 86% (19 out of 22) of the illegal cannabis edibles tested contained multiple pesticides, in many cases at levels several hundred times above Health Canada’s limits. THC levels in those edibles were also often much lower than advertised.
British Columbia has released similar testing results looking at illicit products, as well.
