In the wake of the EVALI (e-cigarette or vaping use-associated lung injury), it’s up to state regulators to do their homework, study the research, and better understand what inhalable product ingredients might be harmful and at what levels. In late 2021, the Pennsylvania Department of Health issued a sudden statement cautioning cannabis consumers that they were reviewing vaporizable products that contained added ingredients such as terpenes or flavorings to determine if there are health issues associated with these ingredients. This undertaking comes at the five-year point in the Pennsylvania medical cannabis industry, which is surprisingly late to say the least.
Section 28 Pa. Code § 1151.27 discusses additives in cannabis products, essentially saying that no ingredient can be added that changes the product’s organoleptic properties (amongst other attributes) unless the grower/processor has obtained the written approval of the Department. Some grower/processors, however, were clearly adding flavorings into their products such that they more resembled the flavors offered in the tobacco industry via electronic cigarettes and vape juices. One hit, and you could tell that the flavors did not come from cannabis. Perhaps those grower/processors did obtain written approval by the Department of Health, but from what I have been told, the state was not cracking down on grower/processors using these types of ingredients without the state’s approval. These products are often labeled as “flavored” and their names give them away as such to anyone taking the time to look.
Pennsylvania regulators have banned smoking cannabis, using the thought process that smoking is not medicinal. Following that logic, however, why would the state permit product manufacturers to adulterate vaporizable cannabis products with flavorings like root beer, pina colada, or grape that did not originate from cannabis without first determining these ingredients to be safe for inhalation? While those flavorings might be classified as “generally recognized as safe,” that label is for food additives and does not consider inhalation. The fact is we do not know whether breathing certain levels of these molecules is safe.
At one point in Pennsylvania, there was a significant flower shortage, despite no shortage in vape carts or concentrates. Cultivated flower was extracted and did not reach the market as is. Therefore, the funneling of medical cannabis patients to vaporizable products as supposedly a “safer” alternative should have been validated with the science available. What’s more, the fact that the state came onto the scene five years in with warnings to consumers on products they may have been vaping throughout that time is quite disconcerting. If any state is going to reap tax dollars from exorbitantly expensive cannabis products, some of that revenue should be utilized to fund studies through state universities (perhaps they are), hire knowledgeable people to properly research the available science, and/or conduct analytical tests to see what these products contain (e.g., secret shopper). It’s not a small task, but this is a medical industry, and the fact that the state has apparently not done their due diligence prior to a given product coming to market is a disservice to patients hoping to safely treat medical conditions.
While terpenes are beneficial and enhance the effects of cannabinoids and other terpenes, there’s likely a cap on this. I’ve seen anywhere from 0.75% to 16% terpenes in liquid live resin (LLR) products in Pennsylvania. The former seems to defy the definition of LLR; the latter calls in to question what an unsafe level of inhalable terpenes might be?
A 2021 review paper summarized 67 journal articles that investigated some of the main flavorings used in e-liquids such as cinnamaldehyde, vanillin, menthol, ethyl maltol, ethyl vanillin, benzaldehyde, and linalool.  The authors report that at least 65 flavor ingredients have induced toxicity in the respiratory tract, with cinnamaldehyde being the most cytotoxic. Dr. Robert Strongin’s lab considered the health effects of elevated terpene levels and their degradation products with increased heat. [2,3] A 1990 study showed that the pinene isomers, 3-carene, and limonene are highly soluble in blood.  A 2000 study demonstrated the high bioavailability (54-76%) of α-pinene, camphor, and menthol, pointing to the effectiveness of low doses.  The National Cannabis Industry Association suggests no more than 10% terpenes in inhalable products. There’s guidance for e-liquid manufacturers regarding some terpene and flavor concentration limits, as well. These are just a few examples.
So, there is guidance that product manufacturers and regulators can look to for keeping cannabis patients safe. And, of course, adulterants like flavoring agents could be put on product labels. While the legalized cannabis market in Pennsylvania and every other geography is a benediction, after 80+ years of political B.S. that’s coalesced into a disgusting crime against humanity, every cannabis patient deserves more.
Reference Stefaniak AB, LeBouf RF, Ranpara AC, Leonard SS. Toxicology of flavoring- and cannabis-containing e-liquids used in electronic delivery systems. Pharmacol Ther. 2021;224:107838. [journal impact factor = 12.31; times cited = 7]
 Meehan-Atrash J, Luo W, Strongin RM. Toxicant formation in dabbing: The terpene story. ACS Omega. 2017;2(9):6112-6117. [journal impact factor = 3.512; times cited = 39]
 Meehan-Atrash J, Luo W, McWhirter KJ, Dennis DG, Sarlah D, Jensen RP, Afreh IK, Jiang J, Barsanti KC, Ortiz AY, & Strongin RM. The influence of terpenes on the release of volatile organic compounds and active ingredients to cannabis vaping aerosols. RSC Advances. 2021;11:11714-11723. [journal impact factor = 3.36; times cited = 0]
 Kohlert C, van Rensen I, März R, Schindler G, Graefe EU, Veit M. Bioavailability and pharmacokinetics of natural volatile terpenes in animals and humans. Planta Med. 2000;66(6):495-505. [journal impact factor = 3.352; times cited = 173]
 Falk A, Gullstrand E, Löf A, Wigaeus-Hjelm E. Liquid/air partition coefficients of four terpenes. Br J Ind Med. 1990;47(1):62-64. [journal impact factor = N/A; times cited = 60]
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