The Maine Office of Cannabis Policy Publishes Report on Contaminants in Medical Cannabis

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A new report highlights the occurrence of contaminants in medical cannabis products within the state.

Based on data collected in August 2023, a recently published report from the Maine Office of Cannabis Policy (OCP) revealed the types of contaminants found in a sample of medical cannabis products (1). The 49-page report, titled “Harmful Contaminants in Maine’s Medical Cannabis Program,” was the first time the OCP assessed Maine’s medical cannabis supply in this manner, and in addition to providing data to the ongoing discussions around mandatory cannabis testing, it also aimed to explain some of the challenges in Maine’s medical program (1). Medical cannabis became legal in Maine in 1999 (1).

“The information and findings in OCP’s report will help to inform policy discussions involving medical cannabis testing by bringing data and science to this discussion,” stated John Hudak, Director of the OCP (2). “Our primary goal is to protect and empower patients, and we remain concerned that the lack of mandatory testing in Maine’s medical cannabis program puts the state’s 106,000 medical cannabis patients at risk each day of complicating their medical conditions and experiencing symptoms of contamination that can be mistaken for symptoms associated with their condition. This data indicate that Maine’s medical cannabis program needs a comprehensive solution to reform and modernize the system in order to protect Maine’s patients.”


For the report, OCP field investigators collected a total of 120 samples, which were tested at certified and licensed state testing facilities for potency, heavy metals, microbials, and yeast and mold (1). The fail rate for the 101 flower samples was 44.6%, while 42% of all samples contained at least one contaminant (1). Some products failed multiple categories or multiple analytes within a category (1). The findings also included (1):

  • 30 individual samples failed for yeast and mold (25.0% of all samples)
  • 21 individual samples failed for pesticides (17.5% of all samples)
  • 3 individual samples failed for heavy metals (2.5% of all samples)
  • 1 individual sample failed for filth and foreign materials (0.8% of all samples)

The analyte categories for these medical cannabis product tests were the same ones used for adult use products (1). Testing of medical cannabis products in Maine is voluntary, though it is mandatory for the state’s adult use cannabis products (1). The OCP does not have the authority to seize contaminated medical cannabis (1).

Read the full report, including health effects of contaminants, certificate of analysis examples from the tests, and recommended policy changes from the OCP.


  1. Harmful contaminants in Maine’s medical cannabis program (accessed Nov 20, 2023).
  2. Office of Cannabis Policy Report Identifies Harmful Contaminants in 42% of Samples Collected from Maine’s Medical Cannabis Program. Office of Cannabis Policy. 2023.