There is no hotter pre roll market in the country than Michigan.  

With an average unit price of $6.16 – one of the lowest in the country, according to cannabis analytics firm Headset – retailers have sold more than 56.7 million units for a total of more than $349.8 million through the first seven months of 2024. That puts the state of Michigan in the top spot for pre-roll units sold and second place – to much larger California – in pre-roll revenue. 

And sales are actually accelerating, with Michigan posting record high pre-roll sales numbers of nearly $54.9 million in July 2024. 

But if you want to compete in the Great Lakes State’s exciting and expanding marketplace, you are going to need to make sure you understand and follow Michigan’s cannabis testing program. 

In Michigan, state law requires all “raw plant material” be tested for the following:  

• Moisture content and water activity; 

• Residual pesticides and chemicals; 

• Microbial impurities; 

• Mycotoxins; 

• Foreign materials; 

• Heavy metals; and 

• Potency. 

These tests are primarily implemented to safeguard consumers from hidden risks in cannabis products.  

“Laboratory testing minimizes the risk of exposure to pesticides, microbes, heavy metals,  molds, and residual solvents by providing consumers with information about the products they are purchasing and helps to prevent consumption by sensitive populations,” reads the “Sampling and Testing Technical Guidance for Marijuana Products” document created by the state’s Cannabis Regulatory Agency. 

For example, moisture content and water activity measurements are indicators of potential mold growth. When water activity exceeds 0.70 Aw, it creates an environment conducive to mold development, which can be detrimental if ingested. This is why Michigan, like many other states, has set a maximum water activity limit of 0.65 Aw for flower and pre-rolls. 

Heavy Metals Testing in Michigan 

Heavy metals are absorbed through a plant’s roots and can damage all of the body’s vital systems, including the respiratory system, the central nervous system and the reproductive system, even in small doses. That’s why Michigan, like all states, requires products to pass strict heavy metals testing. 

But where most states limit testing to the “Big Four” heavy metals of mercury, cadmium, lead and arsenic, Michigan goes a step farther, joining a handful of states that require testing for chromium and even adding nickel to the list as well.  

Microbials and Mycotoxins 

Though certainly dangerous, heavy metals are less of a threat to human health than microbials and mycotoxins. 

Michigan requires testing for standard microbials like yeast, mold, E. coli and salmonella, as well as Aspergillus flavus, fumigatus, niger and terreus.  

As for mycotoxins, toxic compounds produced by molds, such as Aspergillus, can suppress the immune system and cause liver damage, so testing for them is certainly a health and safety issue. Michigan law requires testing for Aflatoxin B1, Aflatoxin B2, Aflatoxin G1, Aflatoxin G2 and Ochratoxin A, requiring all to be less than 20 parts per billion to receive a passing grade. 

Pesticides and residual chemicals 

Michigan allows the use of some pesticides and other chemicals on cannabis, but only those appearing on the Michigan Marijuana Pesticide List, which was updated in early 2024. Pesticides on that list have been reviewed for use by the Michigan Department of Agriculture and Rural Development (MDARD) and may be used in accordance with the label instructions. 

For testing purposes, state law requires labs check cannabis for 58 different residual chemicals, each with their own action limits. 

Keeping your pre-rolls in compliance 

Michigan regulations require tests be conducted in the product’s “final form,” though that applies to the flower itself, according to an email from the Cannabis Regulatory Agency. 

“If the pre-rolls were tested as flower, that would be considered final form testing unless something was added to materially change the product,” they wrote. 

But with so much time and effort spent ensuring your cannabis stays in compliance with state regulations, why would you want to pack it into pre-rolled cones that haven’t also been tested? 

To ensure your cannabis stays clean, only use pre rolled cones that that have also been tested for microbials, pesticides and heavy metals. Medical patients in particular need to be careful to ensure that the paper in their pre-rolls isn’tgoing to make them sick, whether they buy them at a dispensary or pack pre-rolls at home. 

In fact, a study from California’s SC labs found that 11% of rolling papers they tested would fail that state’s testing regiment, which doesn’t even include Chromium, and that 90% of rolling papers contained heavy metals with more than 8% containing them at a rate above the allowable limits. 

In fact, this year, a team of researchers from Michigan this year tested 53 commercially available pre rolled cones and rolling papers and found varying levels of heavy metals throughout the samples, many of which would have caused failures if included in testing. 

“Even if testing is not required, any one issue can harm your brand,” says Custom Cones USA Compliance Manager André Bayard. “It’s important to make sure you work with a company that is as focused on keeping your products in compliance as you are.” 

Bayard always recommends confirming your pre-roll supplier has COAs available to prove their products are clean and will pass tests, or will send you samples for you to test before committing to a full order.  

“Make sure your supplier is focused on those requirements and is trying to set the industry standard with their products,” Bayard says. 

Join Us for More Exclusive Insights on the Michigan Marketplace

Striving to stay informed about Michigan’s dynamic cannabis industry? Mark your calendars for our upcoming Michigan Stakeholder Summit being held in Detroit, MI on Thursday, September 12th.

At the Michigan Stakeholder Summit 2024 you’ll be able to dive deep into the latest trends, regulations, and opportunities shaping Michigan’s cannabis landscape, including hearing directly from Brian Hanna, Executive Director of Michigan’s Cannabis Regulatory Agency. All industry professionals are invited; NCIA members attend free. Register here to secure your spot.