There are a variety of ways to consume tobacco or its components. The three most common forms are unheated, heated, and combusted tobacco and nicotine-only.
The non-combusted technologies are often discussed, evaluated, and disputed in terms of their THR value or lack thereof.
The following systems are compared below; some of them may differ in terms of the possible THR ranking that each consumption might receive.
1. Combustion methods include:
- Cigars
- Pipes
- Cigarillos
- Cigarettes
2. Vapourising can be used to heat but not combust (burn) tobacco:
- Shisha/waterpipes
- HnB cigarettes (heat-not-burn)
- Vaporizers that use solid materials/vegetable matter (‘herbal vapourisers’)
The two most important features of tobacco vaporizers are (1) they do not combust the tobacco, and (2) they combine or separate the fuel exhaust and tobacco vapour supply to the user.
There’s a big difference between people with a single air channel for all combustion and vapour products and those with two separate channels.
3. Smoke-free, tobacco-free inhalation systems, often flavoured, include:
- Inhalators (small medical devices, often for NRT delivery)
- E-cigarettes
4. Oral tobacco:
- Swedish Snus
- Other Types
1. Combustion
The chopped tobacco leaf is burnt, and the smoke released contains the original components of tobacco but with the disadvantage that numerous pyrolytic chemicals are formed as well: carbon monoxide, additional aldehydes, several carcinogens, and a variety of other pyrolysis by-products (burning).
Combustion methods in group 1 burn the vegetable matter.
Inhaling methods include mouth inhalation only or a complete inhalation. Cigar and pipe smokers frequently breathe into their mouths or draw with shallow breath.
Avoiding inhalation is thought to reduce the risk of lung diseases, such as asthma, emphysema, and cancer.
It is claimed that lung cancer from smoking was unknown until cigarettes were developed, but this may ignore the fact that determining the cause of death was not reliable at the time.
2. Plant Vapourising
In the second group of techniques, tobacco is heated without being combusted (burned). The most significant aspect is how the air supply for the fuel combustion is separated, or not separated, from the vapour supply channel.
There are three distinct categories of device:
2.a. The shisha tabletop pipe is designed with one air channel. The fuel-air supply and exhaust both use the same channel as the tobacco vapour, simply a single air inlet and outlet.
2.b. The butane type: These portable units generally have two air channels, which allows the gas exhaust to be separated from the vapour output to the mouthpiece.
2.c. The electronic type: there’s no combustion in this method, as it uses a battery and heater coil. There is only one air channel, but it isn’t relevant because no fuel is burned.
A comparative measure for convenience
When comparing these devices to a cigarette, it’s helpful to make use of a time-based or quantity-based comparative measure.
For example, an HnB cigarette lasts the same length of time (maybe 6 minutes) and quantity (maybe 10 – 15 puffs) as a traditional cigarette.
The number of puffs is more useful since it relates to the amount of inhaled aerosol. For ease of reference, we may refer to this approximate value, for example, as 12 puffs – one cigarette equivalent session or 1 CES.
2.a. types
Shisha, hookah, argilah, waterpipe, hubble-bubble has been popular for a long time in the Middle East and elsewhere.
The devices are somewhat varied worldwide, with most utilizing ignited charcoal in a tray below the tobacco or hot coals above it, with the tobacco being well-mixed with other substances such as mint.
Air is drawn in through a mouthpiece at the end of a pipe, which is often flexible. The heated air from the burning charcoal passes through the vegetable matter, heating it without causing combustion.
There may be more than one pipe (multi-user) in the system. Some gadgets have a water cooling chamber that the air goes through.
Because this category of device has just one air passage channel, users ingest all the combustion by-products and the tobacco/plant/fruit vapour (these devices are generally used with a tobacco mix, not pure tobacco; mint, fruit and molasses are frequently used).
The THR value is that no tobacco is combusted; however, the advantages are offset by (a) the fuel exhaust is consumed (carbon monoxide and other pyrolysis products), and (b) a session can be considerably extended when compared to a single cigarette, perhaps exceeding 45 minutes; this may be 10 CES units or more.
The absence of tobacco pyrolysis products must be weighed against many times the volume of fuel exhaust and tobacco vapour breathed in overtime, which is far greater than a single cigarette equivalent.
It means that the THR benefit is limited or possibly non-existent.
HnB cigarettes have been in the works for decades, and some versions have been offered for a short period in the United States, where they were banned for a variety of reasons (it is too easy to apply any one reason to anything in this market).
HnB cigarettes typically have a charcoal plug at the ‘cigarette’ end and a tobacco filler in the tube’s body.
The charcoal tip is lit, and the hot air is drawn through the tobacco, which is not burned. Here, you can see how one of these devices compares to shisha. This type of gadget has only one air passage channel.
The FDA’s decision to prohibit HnB was motivated, in part, by concerns regarding the potential risk posed by an unknown new tobacco product. However, many other factors may also be considered.
The risk reduction due to no tobacco burning and just the one cigarette equivalent session (cf shisha) for HnB cigarettes is substantial, although, with a single air channel, there is a limit to the THR value; we have no idea of the percentages or other method of calculating risk since this would require 30-year research.
Without a doubt, disease rates would drop by some percentage if all smokers switched to HnB cigarettes since they are 1 CES and contain little tobacco smoke (it is not reasonable to claim there is none at all; there will be some solid particles).
The disadvantage is the single air channel, which means that fuel exhaust substances are breathed in.