Lab Testing Medical Cannabis: Who? Where? What? How? And Other Critical Questions

In February 2017, a Los Angeles television news team broke a story that caused immediate ripples of concern across the medical cannabis community in California.  The team collected 44 cannabis flower and vape cartridge samples from 15 different dispensaries, then sent them out to Steep Hill Labs for testing.

Of the samples, 41 (an astonishing 93 percent) were found to have levels of pesticide contamination that would have excluded the products from sale in states that regulate cannabis pesticide levels–states like Oregon, Massachusetts, Nevada, and Washington. (The story drew a wide variety of reactions and statements from the growers, manufacturers, and vendors, ranging from acknowledgment and deep concern to defensive dismissal.)

California does not currently regulate pesticide use on cannabis. In fact, the state does not require testing of medical marijuana or medicinal cannabis products to verify safety, potency profiles, or even to verify that the flowers, concentrates, edibles, or oils actually are what their labels say they are. (This will change very soon, however; the state has issued proposed regulations for testing and is currently in the comment period on those regulations.

In the current “Wild Wild West” situation, patients may believe, for example, that they’ve purchased a specific strain with a particular THC/CBD and terpene profile, but without independent lab testing, there’s actually no way of verifying that the budtender at the dispensary sold them is what they need for their medical condition—or that it’s free of contamination by molds, mildew, bacteria, fungi, pesticides and other contaminants.

This can be a potentially serious problem for people who use cannabis to treat illnesses that can suppress the immune system. Inhaling any of these contaminants could be

dangerous—even deadly—to patients treated with chemotherapy or stem cell replacement, for example..

“In an industry that’s unregulated in California, and largely unregulated or illegal in the rest of the country, what we have right now out in the field is a hodgepodge of practices,” says Tony Daniel, Vice President of Global Sales and Marketing at Steep Hill Labs. “We look forward to the day when there are consistent federal standards that cross state lines and provide guidance to patients and doctors on best practices in cannabis medicine. If we are more serious about treating cannabis as medicine, and we are supplying it in good faith to people who are immune-compromised and have other serious medical problems, then having a supply chain that could be rife with contamination amounts to a broken system.”

But Is the Problem Always with The Cannabis Itself?

Issues around variances in results of lab testing of cannabis aren’t new.  In 2015, a story circulated out of Oregon that seemed to raise questions about the cross-lab validity of testing itself. A publication sent out samples of an identical batch of medical cannabis to four different labs, and the reports that came back showed four significantly different sets of results, not only in terms of the samples’ THC and CBD content, but also quite different levels of mold and pesticide contamination.

How could that be?

To start with, just as cannabis itself, the labs that test cannabis are not federally regulated.  Neither are the specific procedures they use, nor the sampling, handling, transportation, or delivery procedures used to get samples to testing labs.

“Ideally, as the medical cannabis industry matures, we will see the development and distribution of Standard Operating Procedures to assist people who do the sampling in the field,” says Daniel. “Or we may even see a new profession emerge; cannabis testers. Ideally, people would be trained to collect and transport samples to the labs to remove that variable from the equation.”

Variability at Every Stage of Sampling and Testing

While some states with legalized cannabis do regulate or require testing, they don’t necessarily require standardized testing protocols and methods. That leaves a lot of room for human error at nearly every stage of the process.

Unresolved questions that could improve the reliability of lab tests across the board include:

• Who collects the samples? Under what conditions?
• How much cannabis is gathered and provided to a lab to be tested from each crop?
• From which part or parts of the plant are samples gathered? (Flowers that grow higher on an individual plant and receive more light have higher levels of THC, for example, and will provide different lab test potency results than flowers gathered from the bottom of the plant.)
• What specific methods does a particular lab use to conduct its safety, genetic profile, and potency tests?
• How are samples be gathered, handled, packaged, and delivered to the testing lab?

Wide variances in testing results aren’t limited only to plant material itself, either. Edibles have also been found in lab tests to purport potencies on their labels that don’t match the product—either overstating or understating the actual THC content significantly.

Here, too, handling may account for at least some of the variability at some point in the manufacturing process.

“We’ve had people bring us extract to test in an old mason jar that’s been sitting in their personal vehicle, and the sample is simply pulled out with a spoon. That’s not lab-certified sampling procedure,” says Daniel. “We’ve received samples in Tupperware, tin foil, baggies, boxes; we even received an entire pizza once! Only the sauce was infused with cannabis, but the customer asked us to test the entire pizza. It was in a plain pizza box. We see all sorts of unorthodox handling practices, which could certainly affect the test results.”

Contamination or Cross-contamination?

Unlike manufactured pharmaceutical products, which are produced in pristine, clean conditions, cannabis is grown both indoors and outdoors, frequently under variable conditions.  It is often harvested, trimmed, and cured in barns and other non-sterile facilities by seasonal labor, who may work with other agricultural crops, fertilizers, pesticides, etc. Introducing these substances to cannabis during harvest or processing can impact testing outcomes.  Access to sanitation facilities could introduce bacteria such as e. coli or salmonella. Lack of adequate ventilation in processing facilities or improper curing could encourage the growth of molds, mildews or fungi. There are countless points in the production cycle where contaminants can enter the medical cannabis supply chain, unless best practices are applied at all points in the supply chain.

As the industry continues to mature (and barring any unforeseen federal attempts to crack down on medical access to cannabis) patients who need access to safe, verified strains of medical marijuana should welcome more regulation, more standardized testing, more emphasis on standardized sampling and transportation protocols. The costs of testing, as in every FDA-regulated pharmaceutical product, are a part of a responsible patient safety program. The legalization of medical cannabis has already driven down the cost of the product from its days on the black market—a pound of cannabis once cost nearly $7,000 on the street but can be obtained by a medical card holder for only $800.

Finally, patients should be aware of the potential dangers of untested inhaled cannabis for immuno-compromised patients. If they are using cannabis for a condition that raises the odds of infection, the investment in personal lab testing may be one worth making as an advocate for their own health.

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