This is the second article in a multi-part series about vaporizing cannabis. The first article focused on the way vaporizers work, the health benefits of vaporizing, and the viability of vaporizers in delivering medical cannabis. This article will look beyond just the health differences between vapor inhalation and smoke inhalation, and will focus more on the substantial qualitative health differences in the experience between vaporizing and smoking. As it happens, not only are fewer toxins released during vaporizing, there is also a different profile of terpenoids, cannabinoids, and flavonoids that are released as well. Although most of these molecules are not independently psychoactive, they are capable of moderating how THC is metabolized, as well as providing distinctively different sensations and qualities to the medication .This is what may account for the diverse views of medical cannabis patients on the subject of vaporizing, since the respiratory health benefits are well established.
Before getting into the specifics of what chemicals are affected and what changes are brought about, we’ll start with a quick review of how chemicals are released into the air during a vaporization or smoking session. In a vaporization reaction, chemicals are essentially changing from one state to another, similar to the way water vaporizes when placed on a stove. Although the temperature increase may cause chemical changes to the atoms before they are vaporized (such as the de-carboxylation required for the body to metabolize THC) the molecules are essentially changing phase. There is no flame because the chemical bonds that hold together the plant matter are not being broken apart; the heat supplied did not have enough activation energy.
During smoking, however, a combustion reaction, the molecules of the burning substance are combining with oxygen in a chemical reaction that produces oxides and water. The flame or glowing ember is produced as energy stored in the chemical bonds of the plant matter is released in heat and light. This heat is then transferred to surrounding molecules that have not yet reached the temperature required to burn. The truth therefore is, when you are smoking, you are actually also vaporizing quite a bit at a range of temperatures simultaneously! Unfortunately, burning can also dissociate molecules (break them apart) and render them un-absorbable before they can be released into the air.
Why is this important? Go back to your high school chemistry class experiments and think about the range of boiling points of different substances. Some substances boil very quickly (like alcohol, which will essentially evaporate on its own from room temperature), while others require large amounts of heat, such as metals and other molecules that are usually not seen in vapor states. What this means is that how much of each substance vaporizes depends on the specific temperature of the vaporizer. Most vaporizers are set to about 340-400 F max, with the most common temperature being 365. This temperature is generally selected as it ensures THC and CBD delivery while prolonging the time before “burnt popcorn” type flavors permeate the vapor. Cigarettes or joints, on the other hand, burn from between 400 F on the side to over 700 F on the tip when being drawn from. Below is a list of some chemicals that vaporize at higher points that most vaporizers operate at but which are likely present when smoked. This is not an absolute guide to medicating with vaporizers, but provides a good start for medical cannabis patients to understand what factors are impacting their medication sessions.
THCV – One of the most interesting, THCV is the more psychedelic cousin of THC with a boiling point at 428 F. Chemically similar to THC, as the name would suggest, THCV has fewer carbon chains and occurs in a ratio of about 20:1 THC to THCV at most, although strains that favor THCV are now being engineered. Higher amounts of THCV are naturally prominent in African variety strains, such as Durban Poison and Malawi, and it is responsible for acute cerebral effects, but also thought to decrease the likelihood of panic attacks in individuals with PTSD.
Cannabichromene (CBC) – With a vaporization temperature of 428 F, CBC provides a host of benefits, mostly in the area of anti-inflammatory and anti-bacterial and fungal properties. It bears in mind to remember that bacterial infection is more common with smoking than vaporizing and that not all of these anti-bacterial properties necessarily translate to helping the immune system in the human body, however, behind THC, CBD, and CBN, this may be one of the most widely therapeutic substances contained in cannabis.
Linalool – Readers may recognize this terpenoid from the previous terpenoid article. Clocking in at a vaporization temperature of just over 388 F, this may be vaped in some higher temperature settings but may easily be missed in most vaporizers. Linalool has a pleasant, floral scent that contributes to the bouquet of flavors and also has been shown to decrease stress in rodent tests.
Quercetin – Vaporizing at 482 F, this is well out of the range of market level vaporizers. Although it has not been confirmed by the FDA as specifically therapeutic, there is already a large market of quercetin in the vitamin market, with many believing it to be a useful health supplement. Quercetin has been shown to improve exercise tolerance and endurance in athletes, as well as used to prevent atherosclerosis or hardening of the arteries.
Pulegone – Vaporizing at 435 F, little is understood about pulegone and it is known to be harmful in larger quantities when swallowed, although also shown to be a sedative in other cases. This is a great example of a component that might be a benefit of not vaporizing everything vaporizable.
Borneol – This is another common terpenoid in the traditional medicine market, although again, views are contradictory, with large amounts being cited as definite hazards to health by the Department of Transportation. In the industrial market where the substance is used in the manufacture of other products, it is recommended to take all precautions to avoid breathing in the substance and treated as a hazardous substance. However, it has been used successfully as an anti-inflammatory as well, which illustrates the duality of substances. Vaporizes at 415 F.
Terpineols – These vaporize between 408 and 425 F and contribute much of the taste to cannabis. Not surprisingly, they are also used in perfumes, cosmetics, and other highly aromatic products. Arguments about the taste between vaporizing and smoking go both ways, with some patients swearing to smoking as including all the possible aromas, such as these terpineols, with others feeling that smoke and ash cloud the pure taste of cannabis. Both terpineols are anti-biotic.