The concept behind ‘Heat-not-Burn’ is that heating tobacco, rather than burning it, reduces or eliminates the formation of many of the compounds that are produced at the high temperatures associated with combustion. Research has demonstrated that most of the harmful and potentially harmful constituents (HPHCs) in cigarette smoke are formed by thermal breakdown of the tobacco when it is burned. Heat-not-burn therefore offers the possibility of significantly reducing both the number and the levels of HPHCs generated by tobacco products, whilst retaining an acceptable sensory experience for current adult smokers.
Our RRP Platform 1 and Platform 2 both use the heat-not-burn concept. Platform 1 applies fast-acting electronic temperature control to heat tobacco to a pre-defined temperature, whereas Platform 2 uses a pressed carbon heat-source.
Combustion and burning in cigarettes
Burning occurs as a result of combustion, defined as a particular chemical reaction where the reactant molecules, namely the fuel and the oxidant, are mixed and rearranged to become product molecules, with the simultaneous release of heatCombustion: physical and chemical fundamentals, modeling and simulation, experiments, pollutant formation. 2006: Springer..
A standard combustion process occurs in tobacco when a cigarette is lit. The combination of tobacco (fuel) and oxygen in the air generate self-sustaining combustion that consumes the tobacco.
Researchers have estimated that cigarette smoke contains 7,357 chemical compounds from many different classesThe chemical components of tobacco and tobacco smoke. 2013: CRC press.. There is broad scientific agreement that several of the major classes of chemicals in the combustion emissions of burned tobacco are toxic and carcinogenicHow tobacco smoke causes disease: The biology and behavioral basis for smoking-attributable disease: A report of the surgeon general. 2010: Centers for Disease Control and Prevention (US)..
The link between temperature and combustion
During the natural smoulder period of a cigarette in-between puffs, temperatures of between 600 °C to 800 °C occur in the centre of the burning zone.
During a puff, the temperature increases to more than 900 °C at the periphery of the burning zone. The combustion of tobacco results in the formation of smoke (which contains a range of chemical compounds), heat and ash. The image below shows a typical temperature profile in a lit cigarette during the self-sustaining combustion of tobacco, compared with the temperature profile for RRP Platform 1.
The combustion of a cigarette is a high temperature process that causes the complete combustion of the tobacco (both volatile combustion and heterogeneous combustion of the char), ending with the production of a relevant amount of ashes. Ash is not produced with the electronically heated tobacco product.
Click here to see our latest results on the absence of combustion when using Heatsticks in the Platform 1 device.
Heat-not-Burn Reduced-Risk Products
In order to demonstrate that the operation of Platform 1 does not result in the combustion of tobacco, we commissioned a report by an external and independent senior academic specializing in combustion.
The report concluded that combustion does not occur in the tobacco stick used with Platform 1 for a variety of reasons, including that the temperatures in Platform 1 are much lower than the temperatures reached in the tobacco rod of a cigarette (<350 °C compared to 600-900 °C).
We have measured the levels of a number of HPHCs generated in prototypes of both Platform 1 and Platform 2 in comparison to 3R4F. As can be seen in the graph below, all of the measured constituents are substantially reduced in Platform 1 and 2 when compared to the cigarette.