by PMI Science | 12 June 2018

Considering recent news about the Korean Food and Drug Administration’s (KFDA) report on Platform 1, we think now is a good time to review the concept of “tar.” This blog post explains why “tar” measurements are not a useful way to judge the relative risk of tobacco products – cigarettes and smoke-free products alike.

So what is “tar”?  It’s simply the total weight of solid and liquid residue in cigarette smoke after the weight of nicotine and water has been subtractedi.  Expert scientists call it Nicotine Free Dry Particulate Matter (NFDPM).  This measurement is reported as weight of “tar” per cigarette. But the problem is that this weight gives no information about composition of the residue.  It could contain a high proportion of highly toxic chemicals and a low proportion of less toxic ones – or just the opposite.  You have no way of knowing because only a weight is reported. 

There is a public health and scientific consensus that “tar” is not an accurate or precise indicator of risk or harm, and that reporting of “tar” measurements is misleading to consumers. This is why many governments and public health organizations have supported removing tar measurements from cigarette packaging.

The World Health Organization (WHO), in its most recent report on the scientific basis for tobacco product regulation, rejected the usefulness of including tar indications for consumers: “Tar need not be measured, as it is not a sound basis for regulation, and the levels can be misleading.” ii

The European Union’s 2014 Tobacco Product Directive clarified that tar ratings are the wrong metric to identify a cigarette’s level of harm: “the indication of the emission levels for tar, nicotine and carbon monoxide on unit packets of cigarettes has proven to be misleading as it leads consumers to believe that certain cigarettes are less harmful than others.” i

1mg “low tar” cigarettes carry serious health risks, like all cigarettes. This is because, just as with higher “tar” cigarettes, the combustion of tobacco produces smoke that contains high levels of harmful and potentially harmful chemicals.    

When comparing tobacco products, whether they are cigarettes or smoke-free alternatives, it is much more important to analyze the levels of individual toxicants (e.g. benzene) that appear in the smoke or aerosol because they are widely recognized as being relevant to the health effects of smoking.

From the US Institute of Medicine’s landmark report Clearing the Smoke: “For many diseases attributable to tobacco use, reducing risk of disease by reducing exposure to tobacco toxicants is feasible.” iii

With our heated tobacco products, there is no combustion of tobacco.  Instead, the tobacco is heated to generate a vapor with on average 90% lower levels of harmful chemicals, including compared to those in the smoke of a 1mg cigaretteiv We have also demonstrated that Platform 1 vapor does not contain solid black carbon particles, which are present in all cigarette smoke.  In short, science shows that the vapor from heated tobacco products is fundamentally different to cigarette smoke.

Whilst a residue can still be found in heated tobacco products, its composition is so different (see infographic) that it doesn’t provide meaningful information to help assess health risks. Indeed, the German Federal institute for Risk Assessment (BfR) measured NFDPM levels of one of our heated tobacco products in a recent scientific assessment, but unlike the KFDA, they chose not to report a direct comparison in their publication and instead cautioned: “Although the NFDPM value for HNB products can be formally calculated as for the conventional cigarettes, direct comparisons would be misleading.” v


[i] Directive 2014/40/EU of the European Parliament and of the Council of 3 April 2014. (Directive 2014/40/EU), link here.

[ii] WHO, Report on the Scientific Basis for Tobacco Product Regulation: Fifth Report of a WHO Study Group (2015), link here.

[iii] IOM, Clearing the Smoke: Assessing the Science Base for Tobacco Harm Reduction. DOI: 10.17226/10029.

[iv] Comparison between the level of nine harmful chemicals prioritized for focus by a global public health organization, measured in IQOS vapor and information available to PMI in October 2015 on the levels measured in a selection of twenty-seven 1mg cigarette brands in Japan

[v] Mallock, N. et al ., “Levels of selected analytes in the emissions of ‘heat not burn’ tobacco products that are relevant to assess human health risks.” Arch Toxicol. 2018. DOI: 10.1007/s00204-018-2215-y.




Cigarette smoke compared to Platform 1 aerosol

This infographic shows that Platform 1 aerosol and cigarette smoke are drastically different from one another, which is one reason why tar, defined as a measure of the residue in smoke, is not a good basis for comparison.