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19 May 2022

Cannabis Compliance Testing: Everything You Need to Know

Cannabis Compliance Testing

Legalization of both adult recreational and medical cannabis is increasing across the country—and with regulated markets come cannabis compliance testing for a stunning array of products, from dried flower and concentrates to edibles, tinctures and topicals.

As of early 2022, legal recreational use is permitted in 18 states, Washington, D.C., and Guam, and various forms of medical cannabis are approved in 37 states, Washington, D.C., and four territories. Cannabis testing requirements can vary widely, but there’s a common thread: In an effort to protect public health and consumer safety, most state programs require testing and labeling for potency of tetrahydrocannabinol (THC) and cannabidiol (CBD) among other cannabinoids, along with potential contaminants such as pesticides, residual solvents, microbes and heavy metals.

So what is cannabis compliance testing all about? At PSI Labs, we test thousands of cannabis product samples every month at our ISO 17025 accredited facilities in Michigan and California and wanted to share some inside perspective.

Closer Look: What Cannabis Labs in Michigan Test For

Accredited labs in Michigan are required to test cannabis products for the following:

Product Potency

  • Potency analysis

  • delta-9-tetrahydrocannabinol (∆9-THC) level

  • delta-9-tetrahydrocannabinol acid (THCA) level

  • delta-8-tetrahydrocannabinol (∆8-THC) level

  • Cannabidiol (CBD) and cannabidiol acid (CBDA) levels

  • Cannabinol (CBN)

  • Terpene analysis

Safety Concerns

  • Foreign matter inspection

  • Microbial Panel (Total Yeast & Mold, Shiga toxin-producing E. coli, Salmonella, Total Coliforms)

  • Pesticides

  • Chemical residue

  • Fungicides

  • Insecticides

  • Metals screening

  • Residual solvents levels

  • Vitamin E Acetate screening

For most of these categories, compliance testing can be split into two directives:

  1. Determining concentrations of the compounds that are considered positive and / or desired in the final product; and

  2. Ensuring that any unwanted compounds do not exceed state-established safety limits.

If the cannabis sample in question does not meet state standards in any of the potential contaminants listed above, the producer that submitted the sample must either remediate and retest, or dispose of the entire batch that contained the sample and document disposal in Michigan’s cannabis tracking system.

Why Cannabis Lab ISO Certification Matters

Whatever the state program, working with a strong, ethical cannabis lab with rigorous standards is critical to avoiding litigation, allegations of wrongdoing or “testing failures” in which a cannabis lab fails to objectively or accurately test products.

Such testing failures not only erode consumer trust in the regulated cannabis market, they can increase the financial pressures on licensed businesses subject to repeated testing.

The legalization trend is fairly new and regulations for cannabis testing are constantly developing and changing. Consumer protection regulations are on the books in most states, and can be invoked. That said, the current lack of federal oversight and no uniform standards for cultivation, product manufacturing and cannabis lab testing do create an absence of formality that can lead to accusations of impropriety against both producers and testing labs.

There is one important way licensed cannabis labs are proving themselves to operators and consumers: independent accreditation of their testing processes. As of April 2022, of the 26 states that mandated cannabis testing, 18 required some form of accreditation, usually through the International Organization for Standardization (ISO).

The standard for testing laboratories is ISO 17025 (“general requirements for the competence of testing and calibration laboratories”). This ISO certification determines minimum quality assurance, proficiency testing and equipment requirements. There are some states that do not require full accreditation and others that permit laboratories to gradually adopt standards over time. Check your state’s regulatory agency for specific information, and due diligence is key; most labs are not accredited for all of the tests that they perform.

The onus is on the laboratories to have solid governance plans in place and remain agile in order to quickly react to legislative changes, which is something PSI Labs has done since 2015 as the first Safety Compliance Facility to receive both medical and adult-use licenses in Michigan. Cannabis testing represents a daunting regulatory landscape to navigate for those involved in cannabis production and processing, and the scientists and technicians handling the analytical testing.

What Cannabis Products are Tested?

As the nascent cannabis and hemp industries grow, more and more products are being produced that require compliance testing to ensure a product’s potency matches labeling and also meets established safety guidelines.

While dried flower remains the most obvious example, there are many others such as cannabis extract concentrates for smoking and vaping; biomass (including hemp); cannabinoid distillates; infused beverages and foods; pet products; tinctures; and topicals like lotions, bath bombs and lip balms—all must be tested before they can hit the market.

How is Cannabis Tested?

High-Performance Liquid Chromatography (HPLC) is the most precise method for separating, identifying and quantifying THC, CBD and other known cannabinoids.

The HPLC cannabis testing process involves pumps that pass a pressurized liquid solvent containing the sample through a column filled with a solid adsorbent material. Each component in the sample interacts differently with the absorbent material, which results in different flow rates for the different components, and separation of the components as they flow out of the column.

Typically, cannabinoids and terpenes are first quantified due to their importance from a legal standpoint—raw hemp biomass and hemp products must contain less than 0.3% THC, for example—as well as their status as the major defining characteristics of the Cannabis sativa L.  species.

Other common types of testing include Gas Chromatography with Mass Spectrometry (GC-MS), High-Performance Liquid Chromatography with Mass Spectrometry (LC-MS/MS), Liquid Chromatography-Mass Spectrometry (LC-MS) and Visual Microscopic Screening.

Cannabis Potency Testing

The primary cannabinoids of interest for potency tests are THC and CBD (as well as the inactivated “acid” forms of these cannabinoids) because they are the most prevalent.

Because ∆9-THC is psychoactive and a known intoxicant, testing and accurate product labeling is an essential aspect of any compliance testing regimen. Consumer safety is a primary concern when testing for ∆9-THC potency and to establish the cannabinoid profile of a sample. Some states, such as Michigan and Colorado, require additional potency testing of THCA and CBDA, which become activated ∆9-THC and CBD when subjected to certain temperatures—a process known as decarboxylation.

Testing for a complete cannabinoid profile that establishes the existence and amounts of both psychoactive and non-psychoactive compounds is also important for medical cannabis patients to make informed decisions when making their purchases. Other cannabinoids commonly tested for potency using HPLC include: cannabigerol (CBG); tetrahydrocannabivarin (THCV) and cannabinol (CBN). Depending on the requirements of the customer, dozens of additional cannabinoids can be analyzed.

Compliance Testing Beyond Cannabinoids: Terpenes

Cannabis compliance testing extends beyond the cannabinoid profile with terpenes. These are naturally occurring chemical compounds that are responsible for the different aromas and flavors of the cannabis plant. There are hundreds of cannabis terpenes and they’re common in the plant kingdom as well, from citrusy limonene to pungent pinene and floral linalool, a key component of lavender.

Scientific research has documented various medicinal properties of terpenes, and preliminary research suggests that terpenes interact with cannabinoids to create what has been called the “entourage effect,” which is the theory that compounds in cannabis work in concert to create pronounced effects within the body that wouldn’t occur with the compounds in isolation.

Cannabis Product Safety Testing

Testing for cannabis product safety encompasses the presence of foreign contaminants:

Potentially harmful mycotoxins can be present in large quantities if cannabis is grown or processed in an environment that is not climate-controlled and clean. Cannabis plants can provide an attractive breeding ground for mold, bacteria and other pathogens. Proper testing will detect fungus, mold and mildew, and is critical to protecting consumer safety, particularly immunocompromised people.

Pesticides are a prevalent part of our commercial farming infrastructure and both organic pesticides and non-organic pesticides are used to protect plants against weeds, mold, mildew, fungi, insects and other pests. They can also be potentially harmful to humans and animals. Cannabis-infused products like edibles or concentrates can also be more prone to contain elevated levels of pesticides depending on the extraction method used to make cannabis oil. Proper testing is necessary to ensure that the final product falls within established safety parameters.

Heavy metals should also be a component of any testing regimen. Exposures to metals such as arsenic, mercury and lead can be toxic in humans. The cannabis plant is well known for its abilities as a phytoremediator, which means that it absorbs through its roots and retains heavy metals and chemicals in plant tissues at a relatively high rate. To such an extent, in fact, that it is studied for its unique potential to remove unwanted chemicals and materials from soils damaged by mining and other industries.

Residual solvent analysis is also a vital component of product safety testing. Cannabis biomass and hemp biomass are extracted for use in edibles, concentrates, topicals and other products. This is commonly done by using solvents such as butane, propane, acetone or isopropanol to separate cannabinoids from the plant matter. Like some heavy metals, these solvents can be unhealthy when consumed. If a manufacturer is using these types of solvents it is important to get an accurate reading of what, if any, are left in the final product.

Water activity plays an important part in ensuring the safety of cannabis products and maximizing their shelf life. 

Microbial contamination that can occur in extracted oils, edibles or dried flower can cause respiratory complications, allergic reactions or foodborne illnesses. Additionally, any degradation due to chemical reactions can lead to product irregularities in potency, efficacy and ultimately, safety. Water activity should be used to maximize physical, chemical and microbial stability. It provides an additional level of safety and control.

The Cannabis Certificate Of Analysis (COA)

A Cannabis Certificate of Analysis (COA) is the official document that confirms that the regulated product—in this case cannabis—meets detailed specifications for potency labeling and safety. The COA lists results that are performed as part of the quality-control process and should come from an accredited laboratory.

Anyone entering into a cannabis compliance testing scenario should receive a COA that confirms the levels of key cannabinoids like THC and CBD, as well as all safety test results conducted on a given sample. In addition to meeting state requirements for tracking products from seed to sale, COAs are also a useful tool for consumers. This certificate of quality assurance means that consumers will receive exactly what they think they are purchasing in terms of potency, which is an essential aspect of medical cannabis patient and adult-use consumer safety.

Onsite Cannabis Compliance Analysis

Cannabis product safety isn’t limited to testing lab results. An onsite visit from cannabis compliance experts looking at a company’s operations goes a long way toward ensuring that cannabis products produced in that particular facility will be of a certain quality and meet industry standards. There are basic parameters that an indoor cultivation or flower processing facility should operate within to help maintain compliance:

  • General Cleanliness: Lack of attention to standard issues like puddles of water on the floor, open bathroom doors or staff not properly washing their hands.

  • Lighting. Whether using HPS or LED, a certain amount of watts per square foot should be maintained to optimize the growing environment and keep plants safe.

  • Generator. A loss of power can result in plant damage or complete failure. The generator must be able to maintain levels for production, security and critical technology.

  • Carbon Dioxide Alarms. Parts per million readings are essential for staff safety.

  • Airlock Doors. Maintain a controlled environment with some type of airlock barrier between the production zone and office areas. This also relates to proper airflow.

  • Walls. Solid core metal framing is recommended to eliminate contamination risk caused by porous surfaces.

  • Floors. Continuous resin or epoxy coating with wall lips will provide seamless coverage and prevent dangerous contamination.

  • HVAC. A high-grade system to maintain a controlled environment is a major component of any successful grow facility.

  • Security Cameras. Critical for maintaining a controlled environment.

  • Airflow Management. An oxidized or ionized exhaust airflow with a fogger system and carbon filtration will facilitate healthy and safe cultivation.

Transparency and Trust

Trustworthy cannabis compliance testing should be an expected aspect of the industry, but sadly, that is not always the case. Lab inconsistencies, potency inflation and outright fraud are endemic as regulators work to close loopholes and address unforeseen consequences.

In one glaring conflict of interest, some states allow cultivators to select samples to be tested, which might not truthfully represent what is in the bulk of the material headed for the retail market. The rest of the batch could be very different from the sample in question. It is imperative that there are transparency and data-collection standards for all product sampling—to avoid what could be catastrophic outcomes for both cannabis operators and cannabis testing labs, not to mention the end consumer.

As with most fraudulent commercial activities, enforcement eventually catches up with the perpetrators and the participants. That means that a lot of money and time will be wasted by cannabis businesses trying to rectify a testing-related problem when it could have been avoided in the first place by working with an ethical lab operating with transparent practices. Questionable business applications abound, and until there is real federal oversight instead of state boards with inadequate or dubious oversight initiatives, they will no doubt continue.

The cannabis testing industry as a whole will benefit with the introduction of full accreditation, increased investment in technology and strong oversight and enforcement. National compliance standards need to be implemented and embraced to take the cannabis industry fully mainstream. Until then, PSI Labs will continue to operate with transparency and in the best interests of consumers in the markets we serve.

PSI is committed to elevating the cannabis community through scientific accuracy, research, advocacy and consumer safety. If you have questions about any aspects of cannabis testing or are simply looking for guidance, do not hesitate to get in touch.


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