Physics & Chemistry of Vaping vs. Smoking
Vaping and smoking of cannabis involve the application of high temperatures to transform a substance into an inhalable aerosol. The distinction between vaping and smoking lies in the temperature levels employed. At lower temperatures, molecules transition into an aerosol through vaporization from solid or liquid forms. However, when temperatures rise sufficiently, combustion occurs, leading to the conversion of molecules into different substances (e.g., THCA to THC) and potential generation of harmful byproducts. Smoking involves the inhalation of a combination of desired elements (such as vaporized cannabinoids and terpenes) and degradation byproducts, achieved by applying a flame or intense heat to marijuana. The vaporization temperature required for inhalation depends on the specific molecule and its physical form. For instance, THC’s vaporization temperature differs between dried flower and concentrated oil, and may vary among various concentrate types. Generally, THC and cannabinoids in flower vaporize at lower temperatures, around 200 degrees Celsius (392 degrees Fahrenheit), while concentrate vaporizers often utilize temperatures ranging from approximately 220 degrees Celsius to 400 degrees Celsius or higher (752 degrees Fahrenheit). Concentrates are commonly consumed using very hot heating elements, which involve product combustion
Vaping vs. Smoking: How Do They Influence The Experience?
Vaping and smoking have distinct influences on the overall experience. If you vaporize a cannabis concentrate at a lower temperature (<300°C), the experience will differ compared to smoking the same amount of the product at very high temperatures where combustion occurs.
Firstly, the smoke produced from combusted material is likely to contain particles of different sizes than vapor, affecting their lung absorption. Additionally, a significant amount of smoke (and therefore THC) will be lost to the environment. When someone exhales or coughs out a large cloud of smoke, THC is lost. Therefore, all else being equal, smoke will contain less THC because some of it degrades into other substances (which you also inhale).
A study conducted in 2018 examining the effects of smoked versus vaporized marijuana flower found that vaporization tended to result in higher levels of intoxication compared to smoking when the same amount of material was used. This suggests that vaporizers are a more efficient way of delivering THC to the body than traditional smoking methods. Many consumers commonly report that the high from vaporized cannabis feels different from smoking, often favoring the subjective effects of smoking. Even when consuming the same amount of THC, the reason for this preference could be attributed to the presence of various compounds found in marijuana smoke but absent in vapor.
One significant difference between marijuana smoke and vapor is the higher levels of carbon monoxide in smoke, which competes with oxygen for access to red blood cells. This can lead to mild hypoxia, resulting in reduced delivery of oxygen to the body’s tissues. In a recent conversation with Dr. Echo Rufer, a toxicologist at PAX, it was hypothesized that the mild hypoxia associated with smoking may contribute to different subjective effects compared to vaporized cannabis, which some consumers may prefer. Further research is necessary to confirm this hypothesis.
Flavor also differs between vaping and smoking, as well as when vaping at different temperatures. Terpenes, which are small aromatic compounds found in various products, contribute significantly to the flavor of cannabis. Terpenes vaporize at lower temperatures than cannabinoids. Consequently, the ratio of terpenes to cannabinoids changes across different vaporization temperatures. Lower temperatures result in a higher terpene-to-cannabinoid ratio and more pronounced terpene flavor. Whether this is desirable or not depends on personal taste. However, higher temperatures are more likely to generate harmful thermal degradation byproducts. If you use a temperature-adjustable vaporizer, it’s worth experimenting with different temperatures to observe their impact on flavor and vapor smoothness.
Health Risks of Vaping vs. Smoking
When comparing the health risks of vaping versus smoking, assuming your marijuana product does not contain harmful additives and your device is properly designed, vaporization generally produces significantly fewer potentially harmful byproducts compared to combustion (smoking). The lower the temperature used in vaporization, the less likely it is that you’ll be inhaling substances beyond what is present in the starting material. In terms of the volume and variety of potentially harmful compounds inhaled, smoke is unquestionably more harmful than vapor.
Extensive studies on tobacco smoke composition have identified over 90 harmful and potentially harmful constituents, including carcinogens, which contribute to the increased risk of cancer associated with tobacco smoking. While nicotine is the psychoactive and primary addictive component of tobacco smoke, it is actually the harmful byproducts resulting from the combustion of plant material that are responsible for the carcinogenic nature of tobacco smoke. Moreover, from a purely physical standpoint, smoke is hotter and denser than vapor, making it more irritating and physically detrimental to the lungs (again, assuming your vaporized product doesn’t contain any additional harmful additives).
It is important to note that there are caveats and considerations to keep in mind. However, in general, vaporization carries fewer health risks than smoking, making it a safer alternative, provided that the marijuana product and vaporizer are free from harmful additives and designed properly.
Additives & Diluents
In comparison to nicotine products, cannabis oil has a distinct advantage: it can be inhaled without the need for diluents or synthetic flavor additives. Nicotine vape products typically contain around 1-5% nicotine, with the majority of the product consisting of a diluent used to lower the nicotine concentration. This is because high concentrations of nicotine vapor can cause irritation and undesirable effects. No one would want to vape a nicotine product with 90%, 50%, or even 20% nicotine.
On the other hand, cannabis concentrates, such as oils, often have high THC concentrations, regularly surpassing 75% and sometimes even reaching 95-99% THC (e.g., distillate). Cannabis oil does not require the same level of dilution as nicotine to prevent intense physical irritation, side effects, or to achieve the desired psychoactive effects. While cannabis oils may occasionally contain diluents, it is primarily done to maintain consistent THC levels across different product batches. These cannabis diluents are typically used in much smaller concentrations than those found in nicotine vape products and often include botanical terpenes, which are naturally present in raw cannabis oil.
In some cases, cannabis oils may contain other diluents, such as PG/VG commonly used in nicotine vape products. However, cannabinoids require higher vaporization temperatures than nicotine. Therefore, vaping cannabis oil containing these diluents could potentially produce vapor with harmful byproducts. It is crucial to emphasize that illicit cannabis vape products should be avoided altogether. These products may contain harmful or even deadly diluents or additives. The EVALI public health crisis that occurred a few years ago was linked to illicit market cannabis vape products containing vitamin E acetate, which resulted in numerous deaths. For more detailed information, refer to my conversation with toxicologist Dr. Echo Rufer.