View from the lab: What’s happening with pesticides in cannabis?

A new regulatory approach might be the best way to deal with the recent problem with recalls in the ACMPR

The recent recall of medical cannabis products due to the presence of unapproved pesticides has not only raised awareness in Canada of a problem that seems to occur wherever cannabis is grown, but also exposed an apparent gap in Health Canada’s regulatory system. So far three Licensed Producers (LPs) have recalled flower and oil products due to pesticide contamination, which makes this the leading cause of recalls under MMPR/ACMPR. Almost all US states where medical or recreational cannabis is legal have had pesticide recalls, often for the same chemicals that have given Canadian LPs problems.

Like every crop, cannabis is susceptible to diseases and attack by insects. It is a lucky grower who hasn’t dealt with powdery mildew or had a crop ravaged by spider mites. Cannabis is grown under conditions that are ideal for diseases and pests: high plant densities inside indoor facilities or greenhouses where heat and humidity may be high. Given these challenges, it is not surprising that pesticides have been found in cannabis from both regulated and unregulated sources.

What is the current situation with regards to the use of pesticides under the ACMPR?

Health Canada has approved 13 pesticides for use on cannabis. We use the term “pesticides” here because this is how these products are listed by the Pest Management Regulatory Agency (PMRA). However, all 13 are low toxicity products and some are approved for use in organic production. LPs using them do not need to test their cannabis for pesticides because there is no Maximum Residue Limit (MRL) established for the approved products. Health Canada’s Guidance Document,  Technical Specifications for Testing Dried Marihuana for Medical Purposes, specifies that “The microbial and chemical contaminants of dried marihuana must be within generally accepted tolerance limits for herbal medicines for human consumption, as established in any publication referred to in Schedule B to the Food and Drugs Act.” Most LPs select methods from either the European Pharmacopeia (EP) or the United States Pharmacopeia (USP) (both on Schedule B) for these purposes. The EP pesticide testing requirements includes 69 pesticides while the USP includes 70 (the only addition from the EP list is inorganic bromide). Neither list is specific for products known to be used in cannabis production, and they do not include, for example, myclobutanil or bifenazate, which were found in the recalled products.

This situation has led to a disconnect between the pesticides that are known to be used on cannabis and the testing that is required under the ACMPR. If an LP isn’t using pesticides at all, no testing is required. If an LP uses one of the 13 approved pesticides, no testing is required. If an LP conducts a pesticide analysis as a precautionary measure, the majority of testing labs analyze for pesticides found on either the USP or EP lists, and would miss products like bifenazate, myclobutanil, and imidacloprid. We do not imply that LPs are using pesticides, just that they may be overlooked in the very small number of cases where they are present. The full story of how pesticides ended up in Mettrum and Organigram products is not known, but they represent examples of how quality assurance and quality control systems failed to prevent and detect contamination before products were released to patients.

Pesticide analysis at Anandia Labs

Anandia Labs is a Health Canada licensed lab focused exclusively on cannabis science. We offer third party, independent testing services to LPs and patients. Our testing division employs three PhD chemists and a PhD microbiologist, a team that has more than 50 years of combined laboratory experience. We use highly sensitive and selective LC-MS/MS and GC-MS methods to identify and quantify cannabinoids, terpenes and contaminants such as pesticides. In addition, our R&D division is working to decode the complexities of cannabis genetics and breed new strains.

Anandia Labs currently tests for 51 pesticides using UPLC-MS/MS with sensitivities in the low part per billion (ppb) range for most compounds. This list of 51 pesticides is informed by our knowledge of cannabis growing practices as well as the regulatory regimes in states such as Oregon. In addition to our proactive approach in pesticide analysis, we were the only Canadian cannabis testing lab to participate in the Emerald Test, a proficiency test for cannabis analysis. The Fall 2016 Emerald Test included potency (THCA, THC, CBDA, CBD, CBN) and pesticides (abamectin, azoxystrobin, bifenazate, etoxazole, imazalil, imidacloprid, malathion, myclobutanil, permethrin, spinosad, spiromesifen, spirotetramat, and tebuconazole). Anandia Labs scored highly in both potency and pesticide analyses and was awarded Emerald Test certification badges for both.

Pesticide use in cannabis requires caution

Approval of pesticides use in crops requires stringent evaluation for both human and environmental safety. With proper approvals, and supported by education, training, and testing, pesticide use can be safe. Cannabis presents a unique challenge to pesticide regulation because it is most often smoked or vapourized, which may deliver pesticides directly to the bloodstream without detoxification by the gut and liver. Myclobutanil seems to be widely used in cannabis growing, and is a dangerous chemical when heated since it releases toxic hydrogen cyanide. Since many pesticides have similar chemical properties to cannabinoids, cannabis extracts may also concentrate pesticides. At this point, LPs don’t sell concentrated extracts, but there is nothing stopping patients from making such products from cannabis they purchase from LPs. Medical cannabis is also used by seriously ill adults and children, both groups that need special health protections. Therefore, we believe that pesticide approval, use, and testing in cannabis production necessitates special requirements beyond the norm for food crops.

A new regulatory approach is needed

While some critics of the ACMPR argue that the recalls show the system is flawed, we think that this demonstrates that it works. In the Mettrum and Organigram examples, contaminants were identified, albeit after some products had reached patients. Recalls are not unique to the cannabis industry, but rather happen with every type of product: from foods and pharmaceuticals to toys and cars. The regulated cannabis industry in Canada is new and expanding rapidly; some growing pains are expected. But this does not mean that it should be business as usual. The recalls highlight the need for an improved approach to pesticide analysis under the ACMPR, as well as in the future under a legalization framework. Health Canada should update their guidelines to require that pesticides that are relevant to cannabis production (bifenazate, myclobutanil) be included in quality control analyses for product release. LPs should conduct a broad pesticide analysis of each batch, as well as inputs such as soil and fertilizers. We acknowledge that mandatory pesticide testing will add to an already heavy regulatory burden for LPs, but this will ensure consumer safety and help consolidate the ACMPR industry’s reputation as a trusted source of safe products.

- Johnathan Page, John Coleman, and Andrew Waye

Jonathan Page, PhD. is the co-founder and CEO of Anandia Labs and an Adjunct Professor of Botany at the University of British Columbia. He co-led the Canadian team that reported the first sequence of the cannabis genome, and his work has helped elucidate the biochemical pathway leading to the major cannabinoids.

John Coleman, PhD. is the co-founder and COO of Anandia Labs. He has wide-ranging scientific and business background having held leadership positions at the Centre for Drug Research and Development (CDRD), Inflazyme Pharmaceuticals, and Ocean Nutrition Canada. He obtained his PhD in organic chemistry from the University of British Columbia.

Andrew Waye, PhD. plays a key role in designing and implementing the quality control testing of cannabis at Anandia Labs. His expertise is in natural products chemistry and toxicology, with industry experience in environmental toxicology, natural health products, and cannabis biotech. Andrew’s PhD is in Chemical and Environmental Toxicology from the University of Ottawa.

Anandia Labs offers a full range of analytical tests for batch release by LPs, as well as for ACMPR and MMAR patient-growers. Contact us at or 604-822-0253 for more information on our services and pricing.

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