Ethyl maltol has a sweet fruit-like odor and is a common flavor ingredient in ENDS e-liquids. The transfer of the ethyl maltol in aerosol is dependent on the device characteristics. The conservative approach to estimate potential exposure of the flavor chemicals to consumer from the aerosol is to assume 100% transfer from the e-liquid. The frequent and high use of ethyl maltol in e-liquid has the potential to drive a concern about the excess lifetime cancer risk (ELCR).

Therefore, the level of ethyl maltol in e-liquids and its transfer efficiency to aerosol under non-intensive and intensive vaping regime was determined in commercially available tobacco flavored pod-based ENDS. The non-intense vaping regiment utilized was CORESTA CRM81 (puff volume 55 ml; puff duration 3sec; puff interval 30sec.) The intense vaping regiment utilized was, puff volume 110 ml; puff duration 5sec; puff interval 30sec. The methods for the determination of ethyl maltol in e-liquid matrix and its transfer in aerosol was established. Under non-intense vaping conditions, ethyl maltol in commercially pod-based ENDS products transferred at a rate of 85 to 93%. As a comparison, the ethyl maltol in NJOY Ace Classic Tobacco transferred at a rate of 81%. Under intense vaping conditions, ethyl maltol in commercially pod-based ENDS products transferred at a rate of 78 to 91%. As a comparison, the ethyl maltol in NJOY Ace Classic Tobacco transferred at a rate of 76%. The results indicate high ethyl maltol aerosol transfer efficiency from e-liquids in various commercially available ENDS and may impact the ENDS ELCR calculations.