Combustion, Emissions and Toxicological Studies
Cigarette smoke is an extremely complex and hazardous aerosol. It contains more than 7,500 individual chemicals, of which 150 are known to be harmful and more than 60 are known carcinogens[63],[64],[27]
“Combustion equals complexity. Our Smokeless Products are shown not to combust. Without combustion our Smokeless Products have fewer chemicals present in their aerosols/extractions. The chemicals that are present are often greatly reduced compared to those found in cigarette smoke. Laboratory toxicological assessments further demonstrates that the reduction in chemicals result in little or no cytotoxicity, mutagenicity and genotoxicity compared with cigarette smoke.”
Jillian Dewalt
Head of Analytical and Preclinical Science
Global Life Sciences
Smoke is formed when a cigarette is lit and its tobacco and paper combusts (burns). This process happens at temperatures of up to 950°C and combustion will continue if there is enough tobacco (fuel) and oxygen available. If there is insufficient fuel, oxygen or heat, combustion will not occur[65].
Our Smokeless Products Do Not Combust
For our Oral Tobacco Products and Oral Nicotine Pouches, the absence of combustion is self-evident with how they are consumed in the absence of heat. Our Vapour Products and Heated Products utilise controlled heating as part of their operation. Vapour Products have a metal coil/trace that heats the e-liquid to no more than 200°C to deliver an aerosol. Heated Products heat plant-based (tobacco leaf or non-tobacco leaf) material to no more than 400°C. These temperatures are low enough to avoid both ignition and burning and neither Vapour Products nor Heated Products produce smoke.
For our Heated Products we utilise a multistep approach to confirm the absence of combustion. These steps include determining the temperature profile of the Heated Product’s heater and consumable during use; measurement of combustion markers e.g. carbon monoxide; and mapping the thermal degradation of our Heated Product consumables.
Through mapping the thermal degradation of our Heated Product consumables via Thermogravimetric Analysis (TGA), we can determine at what temperature combustion will occur. TGA allows us to incrementally heat a Heated Product consumable from room temperature up to 1000°C whilst we monitor its mass. We complete this assessment in the presence and absence of oxygen, comparing the differences in mass loss to determine at what point combustion occurs. Thermal degradation mapping of our Heated Product consumables has demonstrated that combustion occurs at above 450°C, when significant mass loss is observed in the presence of oxygen but not in the absence of oxygen (Figure 1)[28]. When there is no oxygen, combustion cannot occur. When there is oxygen, combustion occurs above 450°C.
Ingredients of combustion
Thermogravimetric Analysis: Degradation of tobacco whilst heated in air (blue) and nitrogen (orange)
Rapid weight loss in air shows combustion of tobacco occurs above 450°C. Without oxygen combustion cannot occur, which is why there is no weight loss in the nitrogen test.
Figure 1. Thermogravimetric Analysis of our Heated Product consumable in the presence (in air) and absence (in nitrogen) of oxygen
Fewer and Lower Levels of Harmful Chemicals
When tobacco is combusted the smoke produced is incredibly complex with >7,500 individual chemicals present, of which 150 chemicals are known to be harmful, and >60 are known carcinogens[27],[63],[64].With no combustion, the aerosols of our Heated Products and Vapour Products are significantly simpler than cigarette smoke.
Our Heated Products heat a consumable of natural material (tobacco leaf or non-tobacco leaf), which is why its aerosol is the most complex of our Smokeless Products. However, the total number of chemicals in our Heated Product aerosols is >10 times less than in cigarette smoke and their concentrations are significantly reduced[29],[66],[67].
Our Vapour Products contain no tobacco, but the nicotine in the e-liquid is often extracted from a tobacco plant. The e-liquid that comprises high-quality materials is heated to form an aerosol. As a result, our Vapour Product aerosols consist predominantly of the e-liquid ingredients and are >100 times less complex than cigarette smoke[9],[68].
Our Oral Tobacco Products and Oral Nicotine Pouches also have significantly lower levels of chemicals present in their extractions than cigarette smoke. As they contain tobacco, our Oral Tobacco Products have a more complex extraction compared to our Oral Nicotine Pouches. Our Oral Nicotine Pouches are like our Vapour Product e-liquids in that they comprise solely of high-quality materials (often the nicotine will have been extracted from the tobacco plant). Of all our Smokeless Products, Oral Nicotine Pouches have the lowest number of chemicals present in their extractions[30].
This consolidated picture illustrates the visual difference in aerosol complexity for Heated Products (bottom right) and Vapour Products (top right) compared to cigarette smoke (bottom left) and air (top left)[69]. Approximately 10 puffs of each product captured on a Cambridge filter pad show discolouration and is greatest with the most complex aerosol, cigarette smoke.
Figure 2. Cambridge Filter Pads
Our Smokeless Products have >90% fewer toxicants#
In 2008, the World Health Organization recommended the reduction of nine chemicals (‘toxicants’) in cigarette smoke[70]. In our Smokeless Products, on average, these nine toxicants are reduced by 90-95% for Heated Products[29], 99% for Vapour Products[68], and >99% for Oral Nicotine Pouches[30] (Figure 3).
Figure 3. Average % reductions of nine toxicants in our Smokeless Products#
Combustion = Complexity
Figure 4. Our Smokeless Products have fewer chemicals in their aerosols/extractions.
Less Toxic Than Cigarette Smoke
Cigarette smoke is toxic. With fewer chemicals generated in the aerosols and extractions of our Smokeless Products, we use regulatory and contemporary in vitro toxicology tests to understand if this translates to a reduction in toxicity. The regulatory toxicology in vitro tests we employ allow us to assess four types of toxicological endpoints:
01 Mutagenicity:
The ability of a substance to induce permanent changes (mutations) in a cell’s DNA sequence.
02 Genotoxicity:
The ability of a substance to damage DNA or other genetic material within a cell.
03 Cytotoxicity:
The level at which something is toxic to a cell.
04 Cell Stress:
The level at which cells are stressed and/or die through exposure to a chemical/chemicals.
We have compared the toxicity of our Smokeless Products to the toxicity of cigarette smoke. For each Smokeless Product we have observed substantial reductions across in vitro toxicology testing (Figure 5)[71-81].
Figure 5. Smokeless Product reductions in genotoxicity, cytotoxicity and cell stress#
Footnotes
# Comparison with smoke from a scientific standard reference cigarette (approximately 9 mg tar) in terms of the average of the 9 harmful components the World Health Organization recommends to reduce in cigarette smoke.
^ Oral Tobacco Products operate at ambient temperature but placed here as number of chemicals in its extract are in the 100s.
References
A full list of references for this page can be found in the section 11. References.
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