Assessment of toxic emissions from electronic cigarette liquids and sucralose additive.

Abstract

Electronic cigarettes (ECIGs) have always been advertised as a “safer” alternative to combustible tobacco cigarettes. However, according to previous studies, ECIGs produce carcinogens (such as benzene and formaldehyde) and induce inflammation and infections in airway epithelial cells. Oxidants may be one of the culprits of these effects. This is why it is essential to quantitate the reactive oxygen species (ROS) in ECIG emissions. The fluorescent probe, 2’,7’-Dichlorofluorescein (DCFH) was used to analyze ROS emissions. Effects of power, basic liquid composition, and number of coils in the supra- and sub- ohm devices on ROS generation were assessed. This data was compared to the combustible cigarette and to the IQOS device. Results showed that ECIGs intrinsically emit ROS, and depending on the combination of chemical and physical parameters they can emit high levels of ROS comparable to combustible cigarette. The ROS study focused on the basic liquid components (propylene glycol (PG), vegetable glycerin (VG), and nicotine), while a complimentary study focused on one additive, sucralose. The sweetener sucralose is being used in liquids of ECIGs to improve taste. Sucralose under thermal degradation has proven to release hydrochloric acid, which lead to the formation of chloropropanols in the presence of VG. In this study, Nuclear magnetic resonance (NMR), thermal gravimetric analysis coupled with IR (TGA-IR), Fourier Transform Infrared (FTIR), and pH experiments were conducted to assess the gas phase emissions of a sub-ohm ECIG device when sucralose was added to the ECIG liquid. Results showed that the HCl produced catalyzed the reaction of PG and acetaldehyde to produce propylene acetal in the gas phase.