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.

Cigarette smoke is a complex chemical mixture that causes a variety of diseases, such as lung cancer. With the electrically heated cigarette smoking system (EHCSS), temperatures are applied to the tobacco below those found in conventional cigarettes, resulting in less combustion, reduced yields of some smoke constituents, and decreased activity in some standard toxicological tests. The first generation of electrically heated cigarettes (EHC) also resulted in increased formaldehyde yields; therefore, a second generation of EHC was developed with ammonium magnesium phosphate (AMP) in the cigarette paper in part to address this increase. The toxicological activity of mainstream smoke from these two generations of EHC and of a conventional reference cigarette was investigated in two studies in rats: a standard 90-day inhalation toxicity study and a 35-day inhalation study focusing on lung inflammation. Many of the typical smoke exposure-related changes were found to be less pronounced after exposure to smoke from the second-generation EHC with AMP than to smoke from the first-generation EHC or the conventional reference cigarette, when compared on a particulate matter or nicotine basis. Differences between the EHC without AMP and the conventional reference cigarette were not as prominent. Overall, AMP incorporated in the EHC cigarette paper reduced the inhalation toxicity of the EHCSS more than expected based on the observed reduction in aldehyde yields.