There has been a sustained effort in recent years to develop products with the potential to present less risk compared with continued smoking as an alternative for adult smokers who would otherwise continue to smoke cigarettes. During the non-clinical assessment phase of such products, the chemical composition and toxicity of their aerosols are frequently compared to the chemical composition and toxicity of the smoke from a standard research cigarette - the 3R4F reference cigarette. In the present study, it is demonstrated that results of these analytical comparisons are similar when considering commercially available cigarette products worldwide. A market mean reduction of about 90% is observed on average across a broad range of harmful and potentially harmful constituents (HPHC) measured in the aerosol of a candidate modified risk tobacco product, the Tobacco Heating System 2.2 (THS2.2), compared against the levels of HPHC of cigarettes representative of selected markets; this mean reduction is well in line with the reduction observed against 3R4F smoke constituents in previous studies.

A broad range of commercially available electronic cigarette (ecigarette) systems were tested for levels of emissions of harmful and potentially harmful constituents (HPHC), with a particular focus on the carbonyls: acetaldehyde, acrolein, and formaldehyde. The tobacco-specific nitrosamines N′-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-bipyridyl)-1-butanone; the elements arsenic, cadmium, chromium, lead, and nickel; benzene; 1,3butadiene; and benzo(a)pyrene were also quantified. The results show that except for the levels of carbonyls, all types of e-cigarettes performed in a similar manner, and emission levels for HPHCs were generally not quantifiable. However, levels of carbonyls, especially formaldehyde, were highly variable. Overall, the lowest levels of formaldehyde were observed in cartridge systems, which generally achieved substantial reductions in yields in comparison with cigarette smoke. Formaldehyde levels in open tank systems were variable; however, the median formaldehyde levels across different brands were substantially lower than the formaldehyde levels in cigarette smoke. The results for variable-power devices operated at the highest voltage confirmed existing literature data regardless of orientation and differences in puffing regimes. Furthermore, our results show that many products deliver consistent HPHC yields over a broad range of testing conditions (with minimal variability from one device to another, under a range of puffing conditions). However, some products exhibit high variability in emissions of HPHCs. The use of air blanks is further highlighted to assess nonproduct-related contributions to HPHC levels to avoid misrepresentation of the data. Overall, our results highlight that some but not all electronic cigarettes deliver low levels of carbonyls consistently across the full e-liquid depletion cycle under different test conditions. The need for further research and standardization work on assessment of variable-voltage electronic cigarettes is emphasized.

Testing standards for tobacco and related products are an important basis for product science-based regulation. The recent emergence and rapid growth of products offering an alternative to continued smoking for adult smokers who would otherwise continue to smoke, urgently calls for the establishment of quality and assessment standards relevant for these products. The two main categories of products under consideration are electronic cigarettes and heated tobacco products, which both deliver nicotine in the aerosol that is not smoke, because tobacco is not burned in the process, and in particular no solid particles are generated as a result. In the case of electronic cigarettes the need for new testing and product standards is well recognized and relevant initiatives are underway, whereas no testing standards specific for heated tobacco products are currently under development. In the present manuscript, a critical review of the applicability of existing testing standards - which were mainly developed for cigarettes, is provided, and a framework approach is proposed toward developing relevant testing standards to be able to compare aerosol yields across different product categories (cigarettes, e-cigarettes, heated tobacco products).

SUMMARYPrevious investigations by others and internal investigations at Philip Morris International (PMI) have shown that the standard trapping and extraction procedure used for conventional cigarettes, defined in the International Standard ISO 4387 (Cigarettes --Determination of total and nicotine-free dry particulate matter using a routine analytical smoking machine), is not suitable for high-water content aerosols. Errors occur because of water losses during the opening of the Cambridge filter pad holder to remove the filter pad as well as during the manual handling of the filter pad, and because the commercially available filter pad holder, which is constructed out of plastic, may adsorb water. This results in inaccurate values for the water content, and erroneous and overestimated values for Nicotine Free Dry Particulate Matter (NFDPM). A modified 44 mm Cambridge filter pad holder and extraction equipment which supports in situ extraction methodology has been developed and tested. The principle of the in situ extraction methodology is to avoid any of the above mentioned water losses by extracting the loaded filter pad while kept in the Cambridge filter pad holder which is hermetically sealed by two caps. This is achieved by flushing the extraction solvent numerous times through the hermetically sealed Cambridge filter pad holder by means of an in situ extractor. The in situ methodology showed a significantly more complete water recovery, resulting in more accurate NFDPM values for high-water content aerosols compared to the standard ISO methodology. The work presented in this publication demonstrates that the in situ extraction methodology applies to a wider range of smoking products and smoking regimens, whereas the standard ISO methodology only applies to a limited range of smoking products and smoking regimens, e.g., conventional cigarettes smoked under ISO smoking regimen. In cases where a comparison of yields between the PMI HTP and conventional cigarettes is required the in situ extraction methodology must be used for the aerosol of the PMI HTP to obtain accurate NFDPM/"tar" values. This would be for example the case if there were a need to print "tar" yields on packs or compare yields to ceilings. Failure to use the in situ extraction methodology will result in erroneous and overestimated NFDPM/"tar" values. [Beitr. Tabakforsch. Int. 26 (2014) plus correcte de goudron pour des aérosols contenant beaucoup d'eau en comparaison à la méthode décrite par la norme ISO. Le travail présenté dans cette publication démontre que la méthode d'extraction in situ s'applique à une gamme plus large de produits à fumer et de régimes de fumage alors que la méthode décrite par la norme ISO ne s'applique qu'à une gamme limitée de produits à fumer et de régimes de fumage, comme par exemple des cigarettes conventionnelles fumées avec un régime de fumage décrit par la norme ISO. Si une comparaison des rendements entre le HTP de PMI et des cigarettes conventionnelles est demandée, la méthodologie d'extraction in situ do...

SUMMARYPhilip Morris International has developed a heat-not-burn tobacco heating system (THS 2.2) that produces an aerosol without combustion. Adult smokers are anticipated to use the product with differing behaviors, such as puffing volume or puffing frequency, therefore it was important to find an easy way to study how users are exposed to the aerosol constituents. Thus, the intended outcome of this study was to propose and assess a simple approach for the estimation of THS users' exposure to harmful and potentially harmful constituents (HPHCs). THS operates using tobacco sticks (HeatSticks) that include a mouthpiece and a tobacco plug which, when heated, generates an aerosol. The analysis of nicotine retained in the mouthpiece of the HeatSticks during use was identified as a potential approach to estimate users' mouth level exposure (MLE) to HPHCs. Consequently, the following study was conducted with the objectives 1.) to assess the correlation between the quantity of retained nicotine in the mouthpiece (Nicotine MP) of the HeatSticks and the nicotine delivered in the aerosol of machine-smoked products, 2.) to verify the practical range for Nicotine MP based on the analysis of used HeatSticks left by THS users, and 3.) to develop models describing the relationship between Nicotine MP and specific aerosol constituents measured in the aerosol of machine-smoked products. The regular non-mentholated HeatSticks variant was machine-smoked under various smoking regimens to cover the range of anticipated human puffing behaviors. The suitability of this practical range of machine-smoking conditions was verified by collecting used HeatSticks from two different trials conducted with THS users. The determined Nicotine MP distribution indicated that the machinesmoked regimens encompassed the range observed for users. Multiple Linear Regression (MLR) combined with a stepwise approach was used for selecting models describing the relationship between Nicotine MP and specific aerosol constituents. The stepwise approach interactively explores which amongst various tested predictors provides a good fit. The developed models showed good adjusted coefficients of determination (i.e., R 2 adj. $ 0.75) for 28 out of the 43 investigated HPHCs. Previously published studies showed that actual MLE can be estimated from cigarette filter analysis. This study demonstrated that the analysis of nicotine in THS mouthpiece (filter section) corresponded to an estimation of the upper limits of MLE, in line with maximum possible usage conditions. [Beitr. Tabakforsch. Int. 27 (2017) 42-64]