Formaldehyde in Electronic Cigarette Liquid (Aerosolized Liquid)

Background Aerosolized liquid (e-liquid) of electronic cigarettes can be toxic. Beyond the solvent (propylene glycol, vegetable glycerin) and nicotine, little is known about the liquid composition. Formaldehyde, a carcinogen and source of contact dermatitis, has been reported in the vaporized e-liquid, but no studies have assessed the actual e-liquid. Objective The aim of the study was to evaluate e-liquid products for the presence of formaldehyde. Methods Sixteen e-liquid products were purchased and analyzed for the release of formaldehyde using the chromotropic acid method of detection. Results Of the 16 e-liquids purchased, 4 (25%) were positive for the presence of formaldehyde; 2 were flavored and 2 were nonflavored. All positive e-liquids were in pods or disposable electronic cigarette devices, and 2 were purchased from local vape shops. The average nicotine content in the positive e-liquids was 3.85% versus 4.03% in the negative e-liquids. Conclusions The e-liquid products contain toxic chemicals not declared on product labels, as shown in this study with 25.0% of e-liquids containing formaldehyde. All positive e-liquids were within pods or disposable devices. Continued analysis of e-liquids and increased product regulation are needed.