Identification of flavouring chemicals and potential toxicants in e-cigarette products in Ontario, Canada.

Objectives: The current study examined constituents of e-cigarette products on the Canadian market, with a focus on the province of Ontario.
Methods: E-cigarettes were systematically purchased at 80 retail outlets across 4 cities in Ontario, Canada, in January-February 2015. Product constituents were identified using gas chromatography and mass spectrometry. Additionally, tobacco-specific nitrosamines (TSNAs) were quantified in tested products using liquid chromatography with tandem mass spectrometry.
Results: A total of 166 e-cigarette products were purchased, including disposable products (33%), refillable products (14%), and e-liquids (53%). Overall, e-cigarette products had an average of 6.2 (SD = 3.6) flavouring chemicals. E-cigarettes with sweet flavours (e.g., desserts, alcoholic drinks) had a significantly greater number of flavouring chemicals when compared with tobacco- and menthol-flavoured products (p < 0.05). Approximately one fifth (21%) of products contained flavouring chemicals with potential risk of inhalation toxicity (benzyl alcohol, benzaldehyde, vanillin). An additional 8 toxicants (e.g., acrolein, diacetyl) were detected in a total of 14 e-cigarette products. Measurable levels of TSNAs were detected in 70% of tested products.
Conclusion: E-cigarettes purchased in Ontario, Canada, contained several constituents that may present excess risk, including some flavouring chemicals and carcinogenic nitrosamines. Further research is needed to determine whether the levels of these constituents have implications for the magnitude of risk to users. The findings reveal several policy gaps that may be addressed by developing regulatory product standards and labelling practices for e-cigarettes.