Disposable electronic cigarettes - chemical composition and health effects of their use. A systematic review.

Objective: Despite the rising popularity of disposable e-cigarettes, little is known about their chemical characteristics, or their impact on users' health. This work attempts to summarize current knowledge about chemical composition and known health effects of disposable e-cigarettes.

Methods: The literature search was performed in February and March 2024 in Pub Med and Science Direct databases (no time range) by the terms 'disposable electronic cigarette', 'disposable e-cigarette', 'disposable e-cigs', 'cig-a-like e-cigarette', 'cig-a-like electronic cigarette'.

Results: Disposable e-cigarettes contain: nicotine, humectants (propylene glycol, glycerin), flavoring agents (diacetyl, acetoin, triacetin, p-menthone, triethyl citrate, ethyl maltol, 3-hexen-1-ol, methyl anthranilate, α-terpineol, perillartine, benzyl alcohol, vanillin, melonal, methyl dihydrojasmonate, and γ-decalactone), cooling agents (WS-3, WS-23, menthol), carbonyl compounds (acetaldehyde, formaldehyde, propionaldehyde, acetone, acrolein) volatile organic compounds (VOCs) (benzene, ethanol, methanol, styrene, acetylpirazine and 2,3,5-trimethylpyrazine), metals and inorganic compounds (chromium, nickel, manganese, lead, aluminum, and zinc) and reactive oxygen species. Furthermore, there was some evidence of nicotine dependence, risk of cancer and adverse respiratory effects of using disposable e-cigarettes.

Conclusions: Despite the fact that disposable e-cigarettes contain significantly less toxins compared to combustible cigarettes, they include compounds that are absent in such products that may provide health risk in prolonged usage. In addition, there is a limited number of data on the health effect of disposable e-cigarettes, especially in long time period, for never-smokers. Therefore, due to growing popularity of disposable e-cigarettes among young people, who choose them when initiating nicotine use, further research on their long-term impact of on the users' health is necessary.