Evaluation of the Tobacco Heating System 2.2. Part 2: Chemical composition, genotoxicity, cytotoxicity, and physical properties of the aerosol

• Published in: Regulatory toxicology and pharmacology 2016-11, Vol.81, p.S27-S47
• Main Authors: Schaller, Jean-Pierre, Keller, Daniela, Poget, Laurent, Pratte, Pascal, Kaelin, Etienne, McHugh, Damian, Cudazzo, Gianluca, Smart, Daniel, Tricker, Anthony R., Gautier, Lydia, Yerly, Michel, Reis Pires, Roger, Le Bouhellec, Soazig, Ghosh, David, Hofer, Iris, Garcia, Eva, Vanscheeuwijck, Patrick, Maeder, Serge
• Format: Article
• Language: English
• Subjects: Aerosol chemistry; Aerosols; Animals; BALB 3T3 Cells; Cell Survival - drug effects; Computational Biology; Consumer Product Safety; Cytotoxicity; Electronic Nicotine Delivery Systems - adverse effects; Equipment Design; Genomics; Harm Reduction; Harmful and potentially harmful constituents; Heat-not-burn; Hot Temperature; HPHC; Humans; Inhalation Exposure - adverse effects; Mice; Modified risk tobacco product; Mutagenesis; Mutagenicity; Mutagenicity Tests - methods; Particle Size; Risk Assessment; Smoke - adverse effects; Smoke - analysis; Smoking - adverse effects; Smoking - genetics; THS2.2; Tobacco heating system; Tobacco Industry; Tobacco Products - analysis; Tobacco Products - toxicity
• ISSN: 0273-2300; 1096-0295
• DOI: 10.1016/j.yrtph.2016.10.001

The chemical composition, in vitro genotoxicity, and cytotoxicity of the mainstream aerosol from the Tobacco Heating System 2.2 (THS2.2) were compared with those of the mainstream smoke from the 3R4F reference cigarette. In contrast to the 3R4F, the tobacco plug in the THS2.2 is not burnt. The low operating temperature of THS2.2 caused distinct shifts in the aerosol composition compared with 3R4F. This resulted in a reduction of more than 90% for the majority of the analyzed harmful and potentially harmful constituents (HPHCs), while the mass median aerodynamic diameter of the aerosol remained similar. A reduction of about 90% was also observed when comparing the cytotoxicity determined by the neutral red uptake assay and the mutagenic potency in the mouse lymphoma assay. The THS2.2 aerosol was not mutagenic in the Ames assay. The chemical composition of the THS2.2 aerosol was also evaluated under extreme climatic and puffing conditions. When generating the THS2.2 aerosol under “desert” or “tropical” conditions, the generation of HPHCs was not significantly modified. When using puffing regimens that were more intense than the standard Health Canada Intense (HCI) machine-smoking conditions, the HPHC yields remained lower than when smoking the 3R4F reference cigarette with the HCI regimen. •Mainstream aerosol characterization of the Tobacco Heating System 2.2 (THS2.2).•Comparison of the THS2.2 aerosol with the smoke of the 3R4F reference cigarette.•The majority of the toxicant yields were reduced by more than 90% in the THS2.2•The THS2.2 in vitro genotoxic and cytotoxic potencies were reduced by about 90%.•The particle sizes of THS2.2 aerosol and cigarette smoke were similar.