Identification of flavour chemicals and potentially harmful compounds in refill e-liquids sold in Malaysia

E-cigarette has been marketed over years as one of alternative smoking cessation aid offered for consumer worldwide. The addition of flavouring in e-liquid has become a major factor that contributes to the appeal of using e-cigarette among a non-smoker and youngster has raised concerns due to possible risk and hazard outcomes in daily usage is remain unclear to date. In order to fully understand the e-cigarette attributes towards human health and environment; 17 e-liquid products locally sold were bought and analysed by gas chromatography-mass spectrometer (GC-MS) in order to determine the chemical constituent of e-liquid, especially the flavouring additive. A total of 19 out of 41 identified chemical compounds were detected as a new flavouring agent used in e-liquid products since there was no previous report on this. Many of the flavour chemicals possessed a risk of inhalation toxicity because they were classified as corrosive and/or irritant, with only a few having acute toxicity and the potential to cause cancer. Moreover, several chemical compounds to be concerned such as stimulant as well as opioid types were unexpectedly identified in the e-liquid. Thus, this finding indicate that the chemical constituent of e-liquid contained unknown risk of toxicity and further research is needed to fully understand the possibility of adverse effect in using e-cigarette.