Up to half of the products sold in Maine’s medical cannabis market could be contaminated with pesticides, harmful microbes, yeast and mold, according to two studies released this week. 

Medical cannabis in Maine is not required to be tested, while the products for the recreational-use market are. But that could be changing. 

The Maine Office of Cannabis Policy collected 127 samples of medical cannabis from recent inspections and ran them through the same testing process required in the recreational-use program. Of the 127, 57 – or about 45% – would have failed, meaning they contained at least one banned material or substance.

A separate, larger study by Nova Analytic Labs, one of the state’s four licensed cannabis testing labs, found that almost 21% of about 1,400 samples of medical cannabis would have failed the recreational-use pesticide testing panel, compared to just under 4% of 3,200 samples from the recreational-use market.

The failed samples most commonly contained varying levels of myclobutanil, also known as Eagle 20, piperonyl butoxide, bifenthrin, bifenazate and/or imidacloprid, all of which can cause mild to severe health issues in humans. 


The medical samples were provided voluntarily, and since they only received samples from providers already choosing to test their products rather than a randomized selection, the real percentage is likely much higher, said Christopher Altomare, CEO of Nova Analytic Labs.

Altomare estimated that only 10% to 20% of the lab’s business comes from the medical market, and that most of those are just testing for potency, not pesticides.

Maine’s medical cannabis market brought in $305 million last year. In August, there were just shy of 1,900 medical caregivers in the state serving 106,000 medical card holders.

The medical market is no longer a cottage industry of mom-and-pop shops growing medicine for a small number of patients, Altomare said.

“We need thoughtful testing regulations in the medical market,” he said. “At the end of the day, what we (testing labs) do is public and patient safety and I don’t feel that Maine patients are being adequately protected.”



The Maine Office of Cannabis Policy has pushed to institute a mandatory testing requirement, as well as a track-and-trace program that would allow officials to trace any sort of outbreak or contaminant back to the source. But its proposal was met with outcry from medical providers, known in the industry as caregivers, who argued that the requirements would be onerous and costly, forcing them to either close up shop or push price increases onto consumers. Following a 2022 law, any major substantive rulemaking from the department must be approved by the Legislature, and the Office of Cannabis Policy has not officially proposed a testing requirement since. 

But during a webinar Tuesday, John Hudak, the agency’s director, suggested that might not be the case for long.

“If a business model is one in which producing clean cannabis is too costly, there’s something wrong with the business model,” Hudak said, noting that the price-per-gram in the recreational-use market has actually gone down, despite adding additional testing requirements this year.

“We’re not going to focus on profits at the expense of patients’ health,” he said. 

Hudak, who also is a medical cannabis patient, said the issue is one that’s near and dear to his heart. He doesn’t use medical cannabis in Maine because of the lack of testing, he said, adding that the state isn’t doing enough to make sure patients are protected.

Both of the state’s cannabis markets are up against proposed changes from the Office of Cannabis Policy, but neither proposal contains anything drastic.


Hudak said it likely will be some time before his office brings forward any sort of testing requirement, which will surely draw pushback from industry members.

“We have faced … profound resistance from within the Legislature on this issue and from some medical cannabis groups in the state,” he said. “When we take steps towards implementing these types of policies I want to make sure that we’re doing it right, that it’s fully informed (and) that … you have a true regulatory apparatus that can do all of the things that it needs to do to protect patients’ health and to protect the integrity of the medicine.”

That will take time and a track-and-trace system, he said.

As it stands, the Office of Cannabis Policy is limited in what it can do within the medical cannabis program.

Unlike in the recreational-use market, if there’s a problem or they discover contamination, officials have no power to enforce a product hold or order product destruction.

“It’s really limiting,” Hudak said.



Steph Sherer, founder of medical cannabis advocacy group Americans for Safe Access, stressed during the panel Tuesday that contaminants are often an innocent mistake. 

“It doesn’t mean that there’s someone who has some evil plan to contaminate patients,” she said. 

Cannabis is a bioaccumulator, meaning it will suck up and hold onto any pesticides and heavy metals in the soil. Plus, because of the resin on the flower, it’s easy for the plant to pick up bacteria in the air, she said. 

“It is just a natural process of dealing with an agricultural product,” she said.

Some of the pesticides, chemicals and other analytes that the department tests for have a threshold of what’s considered acceptable, like arsenic, which is prevalent in Maine soils and water. 


But others, like myclobutanil, E. coli and salmonella are strictly prohibited, Hudak said. 

Also known as Eagle 20, myclobutinil is a common pesticide and for fruit and vegetable growers. It can be washed off and usually is not a problem. But Eagle 20 transforms into cyanide gas when burned, meaning it’s banned in cannabis, even in trace amounts.  

That and mold were among the highest of the tested analytes found in the medical samples the office collected.

Mold isn’t banned entirely, but Hudak said some samples contained between 30 and 40 times the allowable threshold.

“This is a market of medical patients, (often) people with suppressed immune systems,” he said. “These types of contaminants are bad for anyone and that is exaggerated when we’re talking about medically vulnerable Mainers.”

Sherer agreed.

“I don’t really understand any argument why you wouldn’t want to test medicine for a patient,” she said.

Hudak said the office will release an in-depth report on its testing study in the coming weeks.

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