An Oklahoma cannabis testing lab found mold and yeast in pre-rolls exceeding the Oklahoma Medical Marijuana Authority’s threshold for certain types of grow batches.
Havard Industries, a cannabis testing lab in Oklahoma, tested 15 pre-rolls for their microbial levels from three dispensaries in the state. The study found 14 of them exceeded the threshold of 10,000 colony-forming units for mold and yeast.
“We found that 14 of the 15 samples did fail for mold and yeast and exceeded the upper limit on average of 23% over the limit for flower samples. The one sample that passed tested at 57% of the limit,” according to the study.
Jeffery Havard, director and owner of the lab, said the state’s marijuana authority changed its microbial testing rules a few years ago for certain types of pre-rolls.
“And so this allowed a lot of products to go on the shelf that would have been failing but now, we weren't monitoring for those particular failures,” Harvard said.
Lee Rhodes, OMMA’s chief science officer, said the state’s regulations surrounding microbial testing are from the United States Pharmacopoeia, a nonprofit that provides recommendations and guidelines for pharmaceuticals.
Rhodes said all cannabis in Oklahoma dispensaries is tested for microbials, but the microbial testing rules vary on the batch. He said going forward, he hopes OMMA can get its own laboratory and better communicate with commercial labs to ensure standards.
“So that we can add that extra layer of reassurance for the public that independent testing is double checking the testing that’s out there,” Rhodes said.
In 2023, the marijuana authority was authorized to run its own quality assurance lab and is in the process of setting it up.
What are Oklahoma's rules for microbial testing for pre-rolls?
A single batch is made up of plant material harvested at the same time, collected into one batch and sent to a dispensary, Rhodes said. Meanwhile, a multiple harvest batch is when a grower has a large harvest that results in several batches of cannabis products.
These batches are tested for pesticides, heavy metals and microbials.
If pre-rolls are made from a single batch where its flowers or buds have been tested for microbials, then those pre-rolls have a few more tests to go through to be put on the shelves. They do not have to be tested for microbials again.
But if pre-rolls are made from a multiple harvest, they go through all of the same tests single batches must clear and have further testing on microbials before going on a dispensary shelf.
“The main rationale is that under multi-harvest batches, there's just that many more opportunities for variation to be introduced, as opposed to with a single harvest,” Rhodes said.
Havard said the study is about final form testing. This happens after the cannabis goes through its first round of microbial testing and once it's chopped up then shoved in a pre-roll, it is tested again in its final form.
Somewhere between cannabis in the flower state and getting into pre-rolls, Havard said microbials are introduced but are not tested again for single harvest batches.
He said when testing rules were different for single and multi-harvest batches, the most common failed tests were for mold and yeast for both batches.
Once the state made changes to microbial testing, Rhodes said he did not have a definitive answer on if pre-rolls failed more mold and yeast tests.
When testing for mold or yeast, he said it’s important to note the test is looking for living things under certain conditions during a specific period of time.
“That’s why your food products are recommended to refrigerate them rather than leave them out at room temperature to mitigate growth of any organizations that may be there,” Rhodes said. “So this similar principle applies to medical marijuana.”
For growers and processors, there’s no specific regulations on how to store medical marijuana to prevent contamination but there is the general rule to store medical marijuana in a way to protect against it.
Under OMMA regulations, if a cannabis batch fails a microbial test at whatever time it’s regulated to be tested, it can be decontaminated or it’s disposed of.
Havard said hopefully the study informs consumers.
“I think that we are just kind of seeing that there's a problem here and that we're just trying to address it and make it public knowledge of the issues that we're seeing,” Havard said.
Rhodes said OMMA is looking into applying more testing rules no matter what the product origin. Both Havard and Rhodes suggest for consumers to look at test results when buying products from a dispensary.
This is not the first time pre-rolls have tested positive in the state. Oklahoma and other states like Colorado have issued recalls on certain products for failing mold and yeast tests.
