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

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P> <B>T</B>he effect of flavors on carbonyl compound (CC) emission factors (EF) from electronic cigarettes (ECs) vaping was investigated at the default vaping (voltage) setting in all experiments using a total of 21 lab-made e-liquid samples (five different types of retail flavorant bases: beverage/dessert/fruit/mint/tobacco). Each flavorant base was added to a separate unflavored base composed of a 1:1 mixture of propylene glycol/vegetable glycerol (PG/VG) at four levels (5/10/30/50% (v/v)). The e-liquid CC levels increased linearly with flavorant base content, 1.3–10.5 times (R<SUP>2</SUP>: 0.762–0.999). The vaping CC EFs increased linearly with flavorant base content (if ≥ 10%) from 1.0 to 92 times (R<SUP>2</SUP>: 0.431–0.998). For flavorant base content of 0%, 5%, and 10%, the EFs ranged from undetected to 0.11 μg puff<SUP>−1</SUP> (acetone). The 40-year cancer risk due to formaldehyde (70 kg EC user inhaling 5% flavorant base content e-liquid: 120 puffs day<SUP>−1</SUP>) is estimated to be 2.0E-06 (highest) compared to 1.0E-06 for the 1:1 PG:VG base. Most formaldehyde vaped from the fruit flavored e-liquid was the flavorant base. The CC concentrations in EC liquids (before vaping) were approximately linear with e-liquid flavorant base content. Retail e-liquid product information labels should be guided to provide a complete list of all ingredients, their concentrations, and carbonyl compound EFs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Electronic cigarettes (e-cigarettes or ECs) are designed to deliver nicotine to a smoker. </LI> <LI> The flavorings in e-liquids were considered safe but raised concerns due to potential toxicity. </LI> <LI> In this study, we investigated the effects of flavor content on CC emissions from EC vaping. </LI> <LI> The CC amounts (before/during vaping) was estimated from the flavor content in the e-liquid. </LI> <LI> The effects of flavor content in e-liquids on vaping CC emissions warrant attention. </LI> </UL> </P>