Insights on Cannabis Testing Challenges and Industry Standards: An Interview with Douglas Duncan

What are your thoughts on the recent cannabis product recalls in California due to pesticides?

Douglas Duncan: While I cannot discuss the specifics of any particular recall, I can state that the pesticide involved in the recalls in July has been the subject of considerable debate regarding the “correct” method to quantify it. Chlorfenapyr is a challenging analyte to detect at low levels due to its low ionization efficiency. The industry has debated whether liquid chromatography with a triple quadrupole (LC-QQQ) is more appropriate than gas chromatography with a triple quadrupole (GC-QQQ) for this purpose.

One camp believes that sensitivity challenges can be overcome with specific models or brands of instrumentation, while the other argues that the risk of false negatives is too great.

I would argue that GC-QQQ is more suitable for the separation and detection of Chlorfenapyr. This is because liquid chromatography uses a skimming mechanism to prevent most of the liquid from entering the vacuum, which would raise the vacuum pressure to an unusable level. However, in the process of removing most of the liquid, it also removes a significant portion of the analyte of interest. Conversely, a GC detects a larger proportion of the sample separated on the instrument.

What are your thoughts on the lab shopping lawsuits happening throughout the US?

Duncan: Lab shopping is not inherently bad, but it becomes problematic when it is used solely to seek out high-biased potency results. When a producer knowingly chooses to test with a high-biased laboratory or collaborates with that laboratory to achieve high-biased results, they are defrauding the consumer. Consequently, consumers may feel duped, and can and should protect themselves through legal action.

How pervasive a problem is lab shopping? How do you remain competitive when other labs are willing be unethical?

Duncan: In my opinion, lab shopping is the only way to compete with unethical laboratories, but it is critical for ethical laboratories to highlight all their other selling points. By allowing a producer to shop around, they can learn the high price of high-biased potency.

Our customers deserve the right to compare laboratories head-to-head. In my experience, most customers want "real" numbers. They understand that testing with a laboratory widely accused of potency inflation makes it more difficult to sell their products. Unfortunately, it is rather difficult for the laboratories' clients to distinguish between poor accuracy, poor precision, and unethical practices. Successful laboratories have found ways to communicate the risks and drawbacks of unethical practices.

How do you think the lab shopping lawsuits will impact your state and the nation?

Duncan: I believe the discovery process during these lawsuits will expose common but bad practices in the industry. By doing so, the courts will create a roadmap for determining whether a lab is to be trusted and/or if data should be invalidated. I expect that each lawsuit will initiate an improvement cycle for all serious laboratories.

Is standardization the answer? What are the benefits and potential pitfalls of more standardized methodologies and more oversight of labs?

Duncan: Standardization can be the answer, but it depends on how "standardized" is defined. When the Environmental Protection Agency (EPA) standardized environmental testing procedures, they removed the most effective ways to improve efficiency. Since then, environmental laboratories have produced much more trustworthy data, but the number of successful environmental testing laboratories has decreased as testing prices raced to the bottom. While standardization of methodologies will help, matrix matched reference material will be much more effective.

What are some other major challenges facing cannabis labs currently and what is needed to overcome them?

Duncan: In my opinion, the most significant challenge is the ill-informed or under-informed consumer. Consumers drive the demand for high potency because they desire the highest high. To truly combat many of the problems facing laboratories, we must tread water until the consumer matures. I see the average cannabis consumer as similar to a young adult beginning to drink. The goal is primarily focused on the end result rather than the experience. When I compare extreme high potency material to Everclear, consumers start to understand. While a couple of shots of Everclear will get you to a desired end result, a few mixed drinks offer a much more pleasant experience.

How would rescheduling (or descheduling) of cannabis affect cannabis testing labs?

Duncan: Currently laboratories are unable to obtain reference material due to the scheduled nature of the substance. Reference materials are available to federally licensed laboratories. While cannabis laboratories may apply for a controlled substance license, they would risk all business with clients that do not have that license. With access to true matrix matched reference material at real-world concentrations, labs will be able to prepare, analyze, and monitor results for changes and trends to ensure accurate and precise results regardless of method used. Furthermore, regulators can mandate reference material tested at a certain frequency to validate data collected. Also, proficiency testing (PT) will improve in the same manner. Currently the matrix used in cannabis PTs is a hemp product, therefore tetrahydrocannabinol (THC) levels are below 0.3%. In some tests high levels of THC is the interfering compound and needs to be included at real world concentrations.

What innovations in cannabis testing are you currently working on?

Duncan: I currently serve on the AOAC Cannabis Analytical Science Program pesticide working group. Here we aim to provide guidance for the verification/validation of pesticide methods. Ultimately, we hope to submit a pesticide analysis method validated in hemp and marijuana. A method agreed upon by multiple cannabis laboratories would go a long way to determining what is the “correct” result.