Aspergillus Testing: Everything You Need to Know

Aspergillus is a common type of mold (a microscopic fungus) that is found both indoors and outdoors. Its growth is especially encouraged in humid environments where moisture content is high. While most people breathe in Aspergillus spores every day without getting sick, people with weakened immune systems or lung disease are at a high risk of developing health problems due to Aspergillus. And while Aspergillus cannabis testing is not required in all states due to the rareness of infection, it is still extremely important to test cannabis products for this microbe to ensure the safety of consumers. 

In this blog, you will learn:

• What Aspergillus is and how it affects cannabis  

• How cannabis testing laboratories screen for Aspergillus

• Current testing requirements for Aspergillus in New Jersey

Aspergillus vs. other molds found in cannabis

Because some cannabis may grow in a warm and humid environment, mold and fungal growth, including Aspergillus, is always a risk. There are four species of Aspergillus that are particularly dangerous to cannabis consumers with underlying health conditions: A. flavus, A. fumigatus,  A. niger, and A. terreus. 

Aspergillosis, a condition that develops due to exposure to Aspergillus, is marked by varying symptoms, most commonly respiratory issues. Since the 1970s, the presence of the aforementioned species of Aspergillus in cannabis has caused a small but significant number of cases of Aspergillosis. According to a study published by the Mediterranean Journal of Hematology and Infectious Diseases, there have been multiple documented cases of medicinal cannabis patients who have died from aspergillosis. 

This is thought to be due to the direct inhalation of fungal spores that are present on the surface of the plant. Because the heat required for combustion is not enough to effectively eliminate Aspergillus spores, they can pose a serious risk of infection. Other health problems caused by Aspergillus include allergic reactions, lung infections, and infections in other organs.

When to screen for Aspergillus

Cannabis is susceptible to microbial contamination at nearly every point in the supply chain. Infection can begin while the plant is alive, but it is particularly susceptible during harvest, storage, and curing. 

Testing for moisture content and water activity is important to assess the risk of microbial growth, including aspergillus. 

While some think of moisture content and water activity as interchangeable, they are not the same. While water activity tests intend to measure how susceptible a product is to potential contamination, moisture content testing measures the current amount of water in the cannabis itself.

Because Aspergillus can creep up in the flower, the leaves, the roots, and even laboratory equipment, many experts in the industry agree that testing ought to be conducted at multiple stages in the supply chain, rather than just on the sample submitted to the laboratory for testing. Also known as environmental monitoring, this is a process used heavily within the food industry to ensure compliance with environmental laws and regulations, as well as protect the health of human beings. Environmental monitoring typically involves swabbing surfaces for pathogens and sending those samples out to a lab for analysis. 

Current testing protocol for Aspergillus

Cannabis cultivators are intimately familiar with the issues that mold growth can cause. Not only does mold growth render a harvest unusable, necessitating that it be destroyed, but affected products that have already made it to market would have to be recalled, a colossal expense of time and finances. However, the serious consequences do not necessarily translate to policy. Due to the lack of federal regulation surrounding cannabis testing, there is still no standardized testing requirement for Aspergillus in the many state-level medical or adult-use cannabis programs in the U.S. 

While some states require specific testing for Aspergillus, others require only a general test for Yeast and Mold (TYM). Because Aspergillus has the ability to produce mycotoxins that can go undetected by Yeast and Mold testing, this test may be too broad to ensure that a product is free of Aspergillus.

Additionally, because cannabis is naturally susceptible to both beneficial and harmful fungal burdens, the TYM approach can hurt producers who fail the test due to a high concentration of benign yeast and mold that does not pose a threat to human health. Contrarily, they could pass the test because their sample contains a high level of Aspergillus that is still below the yeast and mold limit. 

According to Medicinal Genomics, the following states require specific Aspergillus testing for either medicinal or recreational cannabis:

• Alaska: A. flavus, A. fumigatus, and A. niger

• Arizona: A. flavus, A. fumigatus, A. niger, and A. terreus

• California: A. flavus, A. fumigatus, A. niger, and A. terreus

• Delaware: A. flavus, A. fumigatus, A. niger, and A. terreus

• Florida: A. flavus, A. fumigatus, A. niger, and A. terreus

• Iowa: A. flavus, A. fumigatus, A. niger, and A. terreus

• Michigan: A. flavus, A. fumigatus, A. niger, and A. terreus

• Missouri: A. flavus, A. fumigatus, A. niger, and A. terreus

• Nevada: A. flavus, A. fumigatus, A. niger, and A. terreus

• New York: Aspergillus species

• Oklahoma: A. flavus, A. fumigatus, A. niger, and A. terreus

• South Dakota: A. flavus, A. fumigatus, A. niger, and A. terreus

• West Virginia: Aspergillus spp. 

Aspergillus and other mold testing for New Jersey cannabis operators

With so many areas of possibility to develop unsafe levels of mold contamination, microbial testing is essential to ensure that the final product is free of microbial contamination. In addition, testing labs can determine how at risk cannabis may be for microbial growth by testing the following:

• Water activity: This is the measure of available moisture that can feed the growth of molds like Aspergillus. This testing is conducted on many types of cannabis products, including flower and marijuana infused products (MIP) like edibles, to ensure that the product will not spoil or become a breeding ground for microbes like Aspergillus. It also helps to make sure that products are safe for proper long-term storage. Typically, a cannabis flower sample has to clock in a 0.65 aW (water activity) or under to pass.

• Moisture content: While moisture is essential to all cannabis flower, moisture content testing helps to ensure that the water present in a cannabis product does not reach levels that encourage the growth of microbes, such as Aspergillus. Typically, cannabis products should fall between 6% - 15% total moisture content, with optimal levels beteen 6%-9%.

While testing for Aspergillus specifically is not required in New Jersey or Maryland, both states require that licensed cannabis cultivators and producers work with an accredited, third-party analytical laboratory like East Hanover, N.J.-based True Labs for Cannabis to perform microbial analysis for mold and mildew. These tests check for microbials that pose a significant health threat to all consumers, including medically vulnerable patients in the state’s medical marijuana programs.

Not required, but highly recommended  

While the development of Aspergillus is extremely rare, it is nevertheless important to test cannabis products for this toxin to ensure the safety of consumers. At True Labs for Cannabis, our microbial testing package conducts screening for all of the following microbes and pathogens, including Aspergillus spp.:

• Yeast

• Mold

• Bacteria: aerobic, coliform

• Aspergillus spp.

• Salmonella spp.

• E. coli

• Shiga toxin producing E. coli (STEC)

• Listeria monocytogenes 

For more information on all available cannabis testing services for cannabis businesses in New Jersey, please visit our full service package here.