The increasing popularity of e cigarettes has led to a diverse array of flavoured e liquid products that continue to increase in chemical complexity. Whilst many of the flavour ingredients used in e liquids can be assessed and deemed to be safe when inhaled, others may be toxic or respiratory sensitizers when the user is exposed above a threshold of toxicological concern (TTC). Consequently, measuring the transfer of target compounds from e liquid to aerosol is of increasing importance in the risk assessment process.

Historically, a standardised approach to assess flavour transfer would be to measure the concentration of the target compound in the e liquid as well as in the collected aerosol and subsequently calculating the relative transfer. However, developing and validating a quantitative assay for many flavour compounds in the fast-moving world of e liquid flavours is time consuming and expensive.

We will present a flavour transfer screening method for compounds amenable to GC/MS. We will demonstrate how it is possible to obtain practicable information on flavour transfer by comparing instrument responses for e liquid and e-aerosol without the need for calibration curves for each of the individual flavour compounds and how this approach compares to quantitative analysis by more established approaches. The use of a “Limit Test” (pass, fail, more information required) is described to show whether the TTC for target compounds in the aerosol has been exceeded and how this information can be used to inform product development.