Cannabis Testing: What is Done and Why it’s Tested

By Samantha Haas

Initially published on Potguide.com---- August 21, 2021

Cannabis testing. It is arguably the most important and complex business the cannabis industry has to offer, and yet, its importance has always been overlooked. But why is it important?

With help from Eric Nagler, Sample Testing Manager at The Spott, a cannabis testing facility in Kalamazoo, Michigan, we will examine what categories are tested to make a cannabis product safe to sell and consume, what those categories include, and why testing is so imperative in the seed-to-sale process.  

In the cannabis industry, cultivators and processors submit products for testing through state-licensed testing facilities. The results of those tests are then presented back to the cultivators and processors on detailed certificates of analysis that prove the product is safe to consume. If the cannabis product’s test results fall within a state-designated range, the product will either be approved or not approved for sale.

“The importance is safety and knowledge,” said Nagler, a 5-and-a-half-year veteran of the cannabis testing industry. “From a grower and consumer standpoint, it really helps educate everyone on what is right for themselves and others.”

Most states require testing for cannabis products to be sold. However, appropriate testing levels for each category vary by state. According to Nagler, there is no uniform way of testing in all states where cannabis is legal; in fact, some states are behind. 

“There’s only a little group in Washington that I’ve heard of where they don’t have to do testing on adult use. They do, do testing, but not as stringently.  

Primarily, the categories tested include cannabinoid potency, contamination, microbial levels, terpenes, pesticides, heavy metals, foreign matter, and, in the case of concentrate testing, residual solvents. The reasoning for testing these categories relates to human safety. If the levels are too high, or in some cases, detectable at all, they could be harmful to humans. The chart below outlines the types of categories and what is tested. This chart provides a general overview, and what is tested per category is not mandatory in all states where cannabis of any form is legal. 

Category	What is tested
Cannabinoid Potency	(Major) Delta-9, THC, THCA, CBD, CBDA, CBN. (Minor) CBC, CBG, CBGA, CBN
Water Activity	Amount of water that is in the plant
Terpenes	(Main) Limonene, caryophyllene, Linalool, B-Mycene, trans-Nerolidol, Pinene
Residual Solvents	Butane, Propane, Isopropanol, Acetone, CO2, Ethanol
Contaminants/Heavy Metals	Arsenic, Cadmium, Chromium, Lead, Mercury, Nickel, Copper (copper is not tested in all states)
Pesticides	Myclobutanil, Dimethyl Phosphate, Astragalus, Organophosphates, Pyrethroids, Carbamates
Microbial	yeast, mold, fungi, coliform, Astragal, E. coli, Salmonella,
Foreign Matter	Bugs, hair, metal shavings, plastic, non-organic material

The importance of testing

Cannabinoid Potency

Testing potency helps determine the potential medical uses of a specific plant. Most forms of THC for example, assist with chronic pain disorders, gastrointestinal disorders, nausea, increase in appetite, chemotherapy, and opioid addiction. While CBD, CBG, and CBN tend to help with things such as neurological issues, anxiety, and insomnia. On a cultural level, potency and cannabinoid percentage also affect what products consumers choose to buy. Potency can change from plant to plant depending on climate, soil type, and age. 

Terpenes

Most labs test for 6 to 10 significant terpenes, but some test up to 26. Terpenes determine the aroma and flavor of the final product. They also have a major role in the effects and therapeutic benefits of a product. Terpenes can assist in healing immune systems and bacterial diseases, as well as chronic pain conditions, and can be found in drinks such as tea and beer, common household spices, toiletries, and face creams. Some, such as caryophyllene can actually act as a cannabinoid. However, consumers should be aware that some terpenes can also be dangerous. Beta-myrcene, for example, is listed on California’s proposition 65 as a chemical that could cause cancer. Additionally, terpenes such as limonene and linalool can cause allergic reactions and irritation to a person’s eyes and skin when detected at high levels.  

Residual Solvents

Concentrates go through the same tests as flower in addition to a residual solvent test. Any solvent used in extraction is not healthy for people to inhale. Unfortunately, they sometimes get left behind in the extraction process. Chronic inhalation of high butane levels, for example, can lead to psychiatric issues, blood disorders, seizures, and cardiovascular issues. In comparison, high levels of isopropanol, CO2, and acetone can cause hypertension, hypothermia, memory loss, and cognitive dysfunction, in addition to the effects of butane.   

Heavy Metals and Foreign Matter

Foreign matter, such as bugs and hair, has the potential to spread disease and germs if not detected. Small amounts of certain heavy metals are required for maintaining good health, but prolonged exposure or consumption can damage the central nervous system and vital organs.

Microbes and Water Activity

Microbes such as yeast and mold, in particular, can cause issues among those with respiratory issues, allergies, or who are immune-compromised. In the case of salmonella or E-coli, severe stomach pain and vomiting can occur. In serious cases, it can cause intestinal damage and raspatory illness. Unfortunately, not all states don’t test for water activity but it is very important to test for it because it goes hand-in-hand with microbial and bacterial growth. Because cannabis is a plant that absorbs what is around it in the soil, it is very easy to have high water activity levels. Additionally, high water levels in cannabis plants can also affect the product’s shelf life.     

Pesticides

According to Nagler, there can be up to 1,000 pesticides present in cannabis but there is not enough data to currently test them all. While some may be able to be destroyed upon combustion, he said that pesticides are the category that can become the most dangerous because, like everything else, their passing levels vary from state to state, particularly when organic products are used.

“There are organic products out there, such as pyrethrin, that are used in the growing process that are not approved in the cannabis market. These shouldn’t be cancer-causing, but there’s no data to confirm it. People need to remember that just because something is organic, doesn’t mean it’s ok for smoking.” 

Nagler added that some states allow small amounts of myclobutanil and dimethyl phosphate (DDVP). These two microbes are significant to note because when heated to a certain temperature, myclobutanil turns to hydrogen cyanide, which was used in the gas chambers during the holocaust, and DDVP is an active ingredient in Agent Orange, which was used in chemical warfare during World War II. 

“That’s not something to mess with and I don’t want anyone being a guinea pig unless they want to be for science. Unfortunately, there are just some things in this industry that we’re still a little disconnected with and that’s why having data on this kind of stuff is so important,” he said. 

This revelation is shocking for sure. However, Nagler said he has seen a big, positive shift in the testing industry just within the past few years.

“Three years ago, pesticide testing was not mandatory in some states that have medical and recreational marijuana. But something that has been cool to see is the progression and education of testing and realizing that there are products out there you can use to prevent high levels of microbials and contaminants that are completely organic and safe.”  

Going forward, Nagler said that even though things have gotten better in the testing industry, there is still room for improvement and more research needs to be done to deliver safe products to consumers. 

“There should be more uniformity across the board as a whole when it comes to testing and the equipment we all use. My goal is to help deliver safe testing for everyone because most of this is not known. Without testing, there’s no way to know what’s in there and that’s my main concern.”