Salmonella typhimurium strains TA98 and TA100 were used to assess the mutagenic potential of a commercially available rechargeable, dual voltage, closed system modular electronic-cigarette (Vype^® ePen, Nicoventures UK). Results were compared to a Kentucky reference (3R4F) cigarette. Two different test matrices were assessed. Aerosol generated from the e-cigarette was trapped on a Cambridge filter pad, eluted in DMSO and compared to cigarette smoke total particulate matter (TPM), generated in the same manner. Fresh e-cigarette and cigarette smoke aerosols were generated on the Vitrocell^® VC 10 smoking robot and compared using a modified scaled-down 35 mm air agar interface (AAI) methodology. E-cigarette TPM (eTPM) was found to be negative in the 85 mm Ames assay in strains TA98 and TA100 conducted in accordance with OECD 471. Freshly generated e-cigarette aerosol was also found to be negative in both strains following a 3-hour AAI aerosol exposure. Positive control responses were observed in both strains, using benzo[a]pyrene and 2-aminoanthracene for TA98 and TA100 respectively. In contrast, cigarette smoke TPM and whole aerosol from 3R4F reference cigarettes were found to be mutagenic in both tester strains, under comparable test conditions to that of e-cigarette exposure.

Currently, limited information exists on the mutagenic activity of captured e-cigarette particulates and whole aerosol AAI approaches. Regulatory standard product testing approaches as used in this study will become important when determining whether e-cigarette aerosols are less biologically active when compared to cigarette smoke, as suggested by the literature and data presented here.