How Does Cannabis Vapor Testing Work?
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Cannabis vaping is gaining in popularity, particularly among the younger demographic of cannabis consumers. But as vaping rates increase, so too do concerns over whether the products are being tested and regulated to the fullest extent.
Multiple US states have now reckoned with cases of toxic metal contamination in legal cannabis vape products, including California, Hawaii, and Michigan. Increased scrutiny has also been piled on following the outbreak of vaping-related lung injuries at the tail end of 2019.
Combined, these two factors have given state regulators a strong incentive to crack down hard with strict vape testing. And they’re beginning to do so. Colorado recently announced its intention to require testing of the actual vapor emissions from cannabis vapes as of 2022.
But how does this testing work?
Cannabis vape emissions testing
Complex Biotech Discovery Ventures (CBDV), a Vancouver-based licensed cannabis and psilocybin research laboratory, recently announced the launch of a new cannabis testing service that would include vapor testing.
Using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectroscopy (HR-MS), the lab can leverage the magnetic properties of nuclei within the compounds that are aerosolized in the cannabis vape emissions to identify what those compounds are and give an accurate quantitation of the levels to which each is present in the vapor.
“Testing what comes out of a heating device is very valuable because there can be – and there are – chemical reactions happening in the consumption of cannabis when vaping. And those obviously cannot be tested beforehand because the reactions have not happened then,” Dr Markus Roggen, CEO and founder of CBDV, tells Analytical Cannabis.
“Testing the oil in the vape cartridge has a lot of value, but it is missing all of the chemical reactions that can happen in the process of vaping. Testing the aerosol is important and right now that is a black hole, basically we don’t know what there is [in the inhaled vapor].”
In the CBDV lab, the testing process starts by loading the vape cartridge into a special mouthpiece, designed to hold it in place while it is “smoked” by a machine. The emissions from the vape – most importantly the aerosolized droplets of cannabis oil and any metal impurities dissolved in these oils – can then be collected on a special pad behind the mouthpiece and sent for testing by the NMR and HR-MS equipment.
On the surface this may seem fairly straightforward. But there are a whole host of factors that make this type of analysis extremely challenging and complex.
Vape devices are not completely uniform; different brands may have different designs of mouthpiece. This is not a problem for a human mouth, but when designing apparatus to vape these products it needs to be taken into consideration. There is also the question of how one produces the vapor. In an ideal situation, the machine would be able to reliably emulate how a real human would breathe.
“You want everything to be exact every single time you are repeating it over. And you want [the apparatus] to emulate how a human actually smokes,” says Brodie Thomson, a research associate at CBDV who developed the lab’s protocol for aerosol testing. “There could be so much research done on this, especially because there are so many parameters and so many variables between different vapes and vape oils, how the person is smoking them, there’s just so many different things to find in the long run.”
Collecting the emissions after they have been generated is equally difficult. These aerosolized cannabis oil droplets will stick to surfaces they come in contact with, meaning that a significant amount of generated material will be lost to surface deposition if the aerosol is not collected soon after it leaves the vape mouthpiece.
“We made a special holder so that we could have a filter that is immediately after the mouthpiece. We 3D printed this special mouthpiece that we could fit around all the different vapes we were testing, and even with that there is deposition,” explains Thomson.
Mandatory emissions testing – does it go far enough?
As of January 1, 2022, a new rule will come into effect in Colorado that will require the actual vapor of cannabis oils and concentrates to be tested for the presence of at least four heavy metals.
Specifically, the rule states that each batch of concentrate or oil for vape devices “must be tested for metals contamination via emissions testing by a Regulated Marijuana Testing Facility” and that the metals contamination test “must include, but need not be limited to, testing to determine the presence and amounts of arsenic, cadmium, lead, and mercury.”
But from a research point of view, it is not enough to simply develop a method that can spot a handful of toxic metals in the vapor. Scientists want a method powerful enough to identify other important compounds that might be harmful – ones that are perhaps only formed by the chemical reactions triggered by the heat of vaping – and then for these to be included in any emissions testing rules.
“Maybe regulators are jumping the gun, because this is not like pesticides where they come up with a list of pesticides that they should test for,” says Roggen. “[With emissions testing] you have to first figure out what compounds are actually in the aerosol.”
“A third-party testing lab tests what they are told to test for. They’re not there to discover new compounds in the aerosol. That’s what we are doing right now [at CBDV], we are working on understanding what compounds of concern are coming out of a vape cartridge.”
“The authorities really have to think about what they want to tell the lab to look for. And then secondly, how they want them to look for it,” Roggen adds. “Do you test a single puff? Is it a single puff at the beginning, middle, or end of the vape cartridge? Do you need to smoke through the whole vape cartridge?”
Of course, there is no indication that regulators would not include new compounds in the emissions testing list if and when they are identified. The new rule, forward by the testing subcommittee of the Colorado’s Marijuana Enforcement Division (CMED), also will not come into effect until January 2022, in order to give labs more time to purchase the necessary instruments and build validated methods for the analysis.
“It was the consensus of the [CMED’s] work group that the emission produced by vaporizer cartridges is much more relevant to consumer and public health than the current model of testing the raw oil contained within the cartridge,” Alena Rodriguez, managing director of Boulder’s Rm3 Labs and chair of the CMED’s sampling subcommittee, told Analytical Cannabis last October, after the rule was formally added to the state’s list of cannabis regulations.
Rodriguez also revealed that future rulemaking sessions could potentially look at expanding emissions testing to other common cannabis contaminants, such as pesticides and residual solvents in the vapor.
“In future rulemaking sessions, which typically happen in the summer in Colorado, the Testing Subcommittee and work group as a whole will consider transitioning other tests on vaporizer delivery devices to emissions testing rather than testing the raw oil (e.g. potency, residual solvents, etc.),” she said.