The effect of flavor content in e-liquids on e-cigarette emissions of carbonyl compounds

Introduction:
This article examines the impact of flavor content in e-liquids on carbonyl compound (CC) emissions from electronic cigarettes (ECs). The study investigates the effects of flavor content on CC emissions using lab-made e-liquids and five different types of retail flavor additives. The researchers measured the CC content in the e-liquids before and after vaping. This summary will outline the key points of the study design, major findings, and the main message.

Key Points:

* The study used lab-made e-liquids with five different types of retail flavor additives and PG/VG mixtures at four concentration levels.
* The researchers measured the CC content in the e-liquids before and after vaping.
* The CC concentration in e-liquids increased linearly with increasing flavor content.
* The vaping CC emission factors increased linearly with increasing flavor content.
* The Fa emission factors from flavored e-liquids increased from 1.2 to 81 times compared with the base e-liquid with increasing flavor content.
* The comparison of EC vaped aerosol samples with liquid samples prior to vaping showed that the a/L concentration ratio of Fa and aa increased 1.5- to 513-fold.
* The percentage of Fa can be apportioned as 0 --92% to the flavors and as 8-- 100% to PG/VG base in liquid samples.
* The proportion of Fa from the five flavors increased with increasing flavor content (5 --50%; e.g., 0-- 98.8%) compared with the base in vaped aerosol samples.

Main Message:
The study demonstrates that flavor content significantly affects CC emissions from ECs, with higher flavor content leading to increased CC emissions. The findings highlight the importance of regulating flavor additives in e-liquids and the need for transparent labeling of e-liquid ingredients, including their concentrations and CC emission factors. The results also emphasize the potential health risks associated with EC use and the need for further research on the long-term health effects of inhaling flavor additives and their thermal decomposition products.

qu, Yao, Ki-hyun Kim, and Jan E. Szulejko. “The Effect of Flavor Content in E-Liquids on e-Cigarette Emissions of Carbonyl Compounds.” Environmental Research 166 (October 2018): 324–33. https://doi.org/10.1016/j.envres.2018.06.013.