Continuum of Risk for Nicotine Containing Products

In the context of tobacco harm reduction – what does ‘safer’ mean? When a smoker draws on a cigarette, the temperature at the tip rises from about 700 degrees centigrade to 900 degrees – enough to melt metals including aluminium and lead – releasing some 7,000 detected compounds, of which at least 70 are carcinogens. Tobacco is also combusted in cigars, cigarillos and pipes. It is these toxins which create (once water and nicotine are filtered out of the smoke) tar, which is one of the main factors contributing to cancer and other cardiovascular and respiratory diseases. No other way of consuming nicotine comes close to the dangers posed by smoking, as the chart below shows. Regarding vaping devices and based on a comprehensive evidence review, Public Health England (PHE) confirmed in its 2020 report their earlier conclusion that: “Vaping poses only a small fraction of the risk of smoking and switching completely from smoking to vaping conveys substantial health benefits over continued smoking. Based on current knowledge stating that vaping is at least 95% less harmful than smoking remains a good way to communicate the large difference in relative risk so that more smokers are encouraged to make the switch from smoking to vaping.”

With heated tobacco products (HTP), the situation is slightly different because tobacco is involved and is heated (at different temperatures depending on the device) although never above 350°C, and so below the combustion temperature of cigarettes. It is crucial to demonstrate that no combustion occurs with HTP. This can be done by showing that the devices work in the absence of oxygen. An independent assessment, conducted for New Zealand’s Ministry of Health, confirmed that no combustion occurs in the heated tobacco product IQOS when used as intended.

PHE and the UK Committee on Toxicity, Carcinogenicity and Mutagenicity of Chemicals in Food, Consumer Products and the Environment considered the available evidence in 2017. The UK Committee on Toxicity (COT) highlighted significant reductions in levels of harmful and potentially harmful constituents (HPHCs) in the aerosol of HTP compared to cigarette smoke and stated that “[t]here would likely be a reduction in risk for conventional smokers deciding to use heat-not-burn tobacco products instead of smoking cigarettes.” COT added that “[a] reduction in risk would also be experienced by bystanders where smokers switch to heat-not-burn tobacco products”.

Most of the scientific and clinical literature on HTP has been provided by the industry. However, the body of independent research on these products is growing. In 2018, PHE reviewed 20 extant studies (12 of which were the product of tobacco company research) and reiterated these points based on the available evidence and noted the potential of HTP: “Compared with cigarette smoke, heated tobacco products are likely to expose users and bystanders to lower levels of particulate matter and harmful and potentially harmful compounds. The extent of the reduction found varies between studies. […] The available evidence suggests that heated tobacco products may be considerably less harmful than tobacco cigarettes and more harmful than e-cigarettes.” Independent analytical chemistry studies on HTP have confirmed manufacturers’ findings showing that HTP products generate much lower levels of harmful constituents compared to tobacco cigarettes.

See also p.71 of the report: Burning Issues: The Global State of Tobacco Harm Reduction 2020