Clearing the air on Aspergillus concerns in cannabis

aspergillus and cannabis

Cannabis is a plant like oregano and other flowering herbs. They have similar structures and life cycles, and they both attract microbials like mold. But when it comes to cannabis and mold, the stakes are a little higher than oregano.

Testing regulations in most states set limits or other guidelines for how many microbes cannabis products can legally contain. In lots of states, this includes Aspergillus. But in others, like Oregon, small business advocates are fighting for actionable limits over a total ban on the fungus.

RELATED: Powdered THC: what is it and how does it work?

What is Aspergillus?

Aspergillus is a fungus that grows on vegetation, especially as it decays. The first species was cataloged in 1729, and now there are over 800 recorded. Four of these species pose a threat to cannabis consumers on inhalable products: A. flavus, A. fumigatus, A. niger, and A. terreus.

A. flavus and A. fumigatus can cause aspergillosis, an infection caused by breathing in Aspergillus common in immune-compromised or asthmatic people. Aspergillosis can cause shortness of breath, wheezing, cough, and fever.

A. niger is a known food contaminant and human pathogen, and A. terreus may cause infections in people with weakened immune systems.

According to the CDC, most people breathe in Aspergillus daily in the natural environment without issue. However, this statement probably isn’t referring to cannabis consumers lighting it on fire and inhaling bong rips of it. As for a cannabis farm, Aspergillus is much more avoidable by indoor farmers, but the battle seems futile for many outdoor and greenhouse farmers.

Aspergillus makes cannabis headlines

Aspergillus and cannabis have shared headlines in a handful of regional papers in the last month. Two batches of marijuana products from the same manufacturer were recalled in Arizona recently. All products were pulled from shelves, and no illnesses have been reported. Arizona is one of 22 states that doesn’t allow any traces of fungi in regulated products.

RELATED: Is hemp-derived delta 9 THC real weed? Find out the facts

Three Oregon farmers joined forces with the Cannabis Industry Alliance of Oregon in a lawsuit against state-mandated Aspergillus testing. In June, two companies faced recalls following the updated pass-or-fail guidelines for the fungi. The lawsuit halted the mandate in August, citing success unless the state makes another attempt.

Advocates hope the state researches and sets an acceptable limit for the fungus rather than failing any plant with traces of it. This is the rule in Iowa, where inhalable products pass as long as they’re under 10 square Cfu per gram.

If the lawsuit wasn’t successful, and the Aspergillus testing was mandated, Oregon farmers would have been forced to invest in remediation technology to remove the fungus with UV light, ozone shock, and other tactics. Whether farms invest in an expensive remediation machine or try to manage without one, the final result would have been a higher price for the consumer. Higher prices leads to lower sales for some brands, which could lead to the loss of their farm altogether.

There is a lot of research on Aspergillus, but no pointed research on repeated consumption of the fungi on cannabis products. Knowing what’s in a cannabis product is one of the touted benefits of regulating the industry. However, the level of public safety depends on how informed the regulations are. As for Aspergillus testing regulations, more research is necessary on actionable limits before levels can be set.

Cara Wietstock is Senior Content Producer of and has been working in the cannabis space since 2011. She has covered the cannabis business beat for Ganjapreneur and The Spokesman Review. You can find her living in Bellingham, Washington with her husband, son, and a small zoo of pets.