This report consolidates scientific evidence substantiating that there is no Environmental Tobacco Smoke (ETS) emitted during use of Philip Morris International’s (PMI) Electrically Heated Tobacco System (EHTS, also known as the Tobacco Heating System 2.2 and marketed in various countries under the brand name IQOS) and that EHTS use has no adverse effect on the air quality according to threshold limits established by existing air quality guidelines and when used in a setting where regulatory norms of adequate ventilation are respected.
- ETS is generated by the combustion of tobacco products. It is composed of sidestream smoke (SS), emitted from the smoldering tobacco between puffs, and exhaled mainstream smoke (MS) from the smoker.
- The absence of combustion of the tobacco contained in the Electrically Heated Tobacco Product (EHTP), when used as intended in the EHTS Holder, and the fact that the aerosol generated during EHTS use is not smoke were scientifically substantiated and the available evidence has been summarized and discussed in a report by Nordlund et al., 2019 .
- The scientific substantiation is based on a review of technical and scientific definitions, an extensive set of published scientific evidence, and expert opinions issued by third party scientific experts in numerous countries as well as by independent research organizations.
- As there is no smoke (neither SS nor MS) generated by the EHTP when used as intended in the EHTS Holder, there is no ETS emitted during EHTS use.
- As the tobacco contained in the EHTP is heated and not burned, the mainstream aerosol generated during EHTS use contains >90% lower levels of harmful and potentially harmful constituents, on average, compared with the MS of a 3R4F reference cigarette.
- The environmental EHTS aerosol (predominantly emitted from exhalation of EHTS mainstream aerosol constituents during EHTS use) is, by nature, different from the ETS emissions from cigarette smoking.
- In addition to demonstrating that the EHTS aerosol is not smoke and that no ETS is emitted during EHTS use, it isimportant to assess the impact of the environmental EHTS aerosol on air quality. PMI conducted scientific studies in a dedicated air quality assessment room under simulated environmental conditions.
- These studies demonstrated that only three compounds were above the background levels in air (nicotine, glycerol, and acetaldehyde) and could be attributed to EHTS use. However, glycerol is not an air pollutant and the concentrations of nicotine and acetaldehyde were much lower than the levels measured after cigarette smoking and far below the limits established by existing air quality guidelines.
- Scientific studies conducted by independent researchers on EHTS (as well as certain e-vapor products (EVP)) use in indoor environments generally corroborated these results. Moreover, the use of EHTS as well as the EVP tested resulted in the lowest concentrations of formaldehyde, benzene, toluene, and particulate matter (PM) PM2.5 when compared with cigarettes, waterpipes, and some common sources of indoor pollution (incense, mosquito coils). Significantly higher levels of benzene, toluene, and formaldehyde can be detected in public environments, where no EHTS or EVP was used, especially in transport micro-environments (Kauneliene et al., 2018 ).
- To better understand the impact of day-to-day activities on air quality and to prepare the assessment of the impact of EHTS use in real-life settings, PMI conducted studies on the impact of activities of daily living, such as using cosmetics, preparing food on a table-top appliance, or simply the prolonged presence of people, on air quality in an indoor environment. The results of these studies showed that day-to-day activities lead to significant emissions of volatile organic compounds and PM, which would need to be considered when assessing the impact of EHTS use on bystanders in real-life settings.
- PMI scientific studies in real-life settings, such as coffee rooms and in IQOS stores, where EHTS use is allowed demonstrated that no quantifiable amounts of PM2.5 were present and that the environmental aerosol emissions of the measured compounds during EHTS use were far below the limits set by existing air quality guidelines.
- In a study conducted in Japan, in a restaurant where EHTS use was allowed but cigarette smoking was not, the results indicated that:
- The use of EHTS did not generate ETS and had no adverse effect on air quality as measured by nicotine, tobacco-specific nitrosamines (TSNA), and respirable suspended particles as well as the carbonyls acrolein, crotonaldehyde, acetaldehyde, and formaldehyde in air in a real-life setting where regulatory norms for occupational exposure in terms of adequate ventilation were respected.
- Non-smokers did not have an increase in exposure to nicotine and TSNAs due to passive exposure to the environmental EHTS aerosol by means of assessing their urinary biomarkers of exposure.
- Non-smokers were not exposed to higher levels of acrolein, crotonaldehyde, ethylene oxide, and benzene in a real-life setting due to passive exposure to the environmental EHTS aerosol by means of assessing their urinary biomarkers of exposure.
- These results were further corroborated by independent scientific studies on air quality conducted in real-life settings in a nightclub and in a catering and entertainment establishment.The studies showed that:
- The particle number concentration was found to be higher when the nightclub was in full operation with no humans present and no use of EHTS compared with what could be measured when EHTS was used and the nightclub was not in operation.
- The levels of all compounds measured in the catering and entertainment establishment during EHTS use were far below threshold limits established by existing air quality guidelines.
- Moreover, the results of an independent study performed in Germany were in line with the results of PMI studies on air quality, with cigarette smoking leading to the greatest impact on air quality. EHTS use resulted in detectable levels of nicotine, but no other chemical markers of contamination were detected, including the absence of markers for secondhand smoke. The confined environment of the car and the proximity of the sample collection to the product user resulted in detection of small liquid droplets in the nanoscale range when EHTS was used in the car.
To summarize, the scientific evidence comprehensively demonstrates that there is no ETS emitted during use of the EHTS and that EHTS use has no adverse effect on air quality and bystanders’ exposure considering threshold limits set by existing air quality guidelines and when used in a setting where regulatory norms of adequate ventilation are respected. Furthermore, it is important to consider exposure to air pollutants existing in the current real life environment to contextualize the impact of products such as EHTS or EVPs in this context.
 Nordlund, M., et al., Scientific substantiation of the absence of combustion and no smoke formation in the Electrically Heated Tobacco Product (EHTP), version 1.0. Scientific substantiation report dated January 21, 2019, Philip Morris Products S.A. 2019.
 Kaunelienė, V., M. Meišutovič-Akhtarieva, and D. Martuzevičius, A review of the impacts of tobacco heating system on indoor air quality versus conventional pollution sources. Chemosphere, 2018. 206: p. 568-578.