Vaping is often considered synonymous with smoking. However, the two are not the same.
Smoking is a practice in which a substance is burned and the resulting smoke breathed is absorbed into the bloodstream. Most commonly, the dried leaves of the tobacco plant which have been rolled into a small square of rice paper to create a small, round cylinder called a “cigarette” are used. Smoking is primarily practiced as a route of administration for recreational drugs use.
Smoke is produced as a result of combustion (temperature > 800 degree C). When combustion occurs, new chemicals are formed via the process of oxidation. Hence, smoke contains thousands of new chemicals different from those initially burned. When a cigarette is smoked, there must be a fire to create the smoke.
Vaping is the act of inhaling and exhaling a vapor or an aerosol. E-cigarettes do not produce tobacco smoke, but an aerosol, which is commonly termed as “vapor” (1, 2).
Vapor: When a substance becomes gaseous, at a temperature that is lower than its point of combustion (180-250 degree C), it is considered as vapor. Unlike smoke, when vapor is produced, no new chemicals are formed. The chemicals that are in vapor are the same as those found in the vaporized substance.
The chemicals that are in a liquid are the same chemicals that are found in the vapor formed from the liquid. For instance, the e-liquid in e-cigarettes includes propylene glycol, food grade flavoring, vegetable glycerin (also called glycerol) and nicotine. All four of these chemicals are FDA approved for human consumption. (3)
Steam inhalation in medicine is also often advised as adjunctive treatment and may help to alleviate symptoms of lung diseases. Steam inhalation is nothing but the inhalation of water vapor.
Aerosol: Unlike vapor, which is simply a substance in gas form, aerosols contain tiny chemical particles. (4) In physics, a vapor is a substance in the gas phase, whereas an aerosol is a suspension of tiny particles of liquid, solid or both within a gas. Aerosol therefore is the state of the intermediate matter between the liquid and the gaseous state. It is composed of particles, which are neither as dispersed as the gas nor as concentrated as that of the liquid.
Nebulizers, both jet and ultrasonic, also produce aerosols from the respective liquid. Depending on the model, nebulizers generate droplets ranging in size from 1 µm to 5 µm.
Inhalation aerosol therapy in medicine uses bronchodilators and steroids as liquid particles suspended for therapeutic purposes.
The main point of difference of importance between smoke and vapor or aerosol is the presence of toxic tar and carbon monoxide in smoke. The smoke particulate matter, minus the water and nicotine, forms the portion of smoke known as tar, which contains most of the mutagenic and carcinogenic agents in tobacco smoke (5).
- de Angelo Calsaverini Leal RC. Inhalation devices: various forms of administration for therapeutic optimization. Open J Asthma. 2017;1(1):037-044.