Chemical analysis of selected harmful and potentially harmful constituents and in vitro toxicological evaluation of leading flavoured e‐cigarette aerosols in the Chinese market

Abstract

Use of electronic cigarettes (e‐cigarettes) has increased significantly over the past decade due to consumer perception that these products represent a less risky alternative to combustible cigarettes. E‐liquids generally contain a simple mix of vegetable glycerin, propylene glycerol, nicotine, organic acids, and flavourings. Regulators require that harmful and potentially harmful constituents (HPHCs) that might cause harm to the consumer must be monitored in the aerosol generated by e‐cigarettes and in cigarette smoke (CS). To quantify HPHCs in aerosols from commercial flavoured e‐cigarettes in Chinese market, this study has systematically compared levels of HPHCs, including eight carbonyls, five volatile organic compounds, four tobacco‐specific nitrosamines, 16 polycyclic aromatic hydrocarbons, and seven heavy metals, in the aerosols of four market‐leading flavoured e‐cigarettes and mainstream CS, alongside in vitro cytotoxicity and mutagenicity assays. The vast majority of HPHCs were either undetected or significantly lower in the e‐cigarette aerosols than in commercial CS or reference CS (3R4F). Where HPHCs were detected, there were small variations among the different flavoured e‐cigarettes. In the neutral red uptake and Ames assays, aqueous extracts of the e‐cigarette aerosols did not induce obvious cytotoxicity or mutagenicity, whereas CS aqueous extract showed dose‐related cytotoxicity and mutagenicity. Collectively, these results indicate that use of e‐cigarettes might potentially lead to a significant reduction in exposure to harmful substances, with fewer cytotoxic and mutagenic effects, as compared with conventional smoking. Further studies based on human puffing conditions and longer evaluation periods will be needed to substantiate this potential.

Ultrasonic Cigarettes: Chemicals and Cytotoxicity are Similar to Heated-Coil Pod-Style Electronic Cigarettes

“…Aldehyde concentrations in SURGE fluids and aerosols were compared to "JUUL" and "Other Brands," which included Ezzy Oval, Hyde, Puff Bar, and SEA (Figure 4). [43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] Methylglyoxal and glyoxal were significantly higher in SURGE fluids and aerosols than in aerosols from JUUL and "Other Brands" (Figures 4 A, C). Glyceraldehyde was significantly higher in SURGE aerosols than in unvaped fluids (Figure 4B).…”

Critical Review of the Recent Literature on Organic Byproducts in E-Cigarette Aerosol Emissions

“…Xu et al The authors [33] quantified HPHCs in aerosols emissions of four marketleading flavoured e-cigarettes available in the Chinese market. Levels of eight carbonyls, five volatile organic compounds (VOCs), four tobacco-specific nitrosamines (TSNAs), 16 polycyclic aromatic hydrocarbons (PAHs), and seven heavy metals where quantified and compared with their presence in mainstream tobacco smoke.…”

The science behind vaping

“…Caruso et al 10 use in vitro assays to assess cytotoxicity, reactive oxygen species, cell morphology and mitochondrial function in human bronchial cells in aerosols from four nicotine‐containing e‐liquids. Xu et al 11 examine four different products available in the Chinese market, first looking at chemistry by assessing the presence of 40 Harmful and Potentially Harmful Constituents in aerosols of e‐cigarettes, and comparing with levels found in cigarette smoke. They then report on cytotoxicity and mutagenicity assays, demonstrating that aerosols from e‐cigarettes are vastly less mutagenic and cytotoxic than cigarette smoke.…”