Dihydroxyacetone levels in electronic cigarettes: Wick temperature and toxin formation

Abstract

Recently, we reported the presence of dihydroxyacetone (DHA), the active ingredient in sunless tanners, in the aerosol of an electronic cigarette. DHA has been shown to react with DNA in vitro. The FDA restricts the use of DHA to external application only. It states that it should not be inhaled, ingested, or come into contact with any areas containing mucous membranes, due to unknown risk. Herein, the quantification of DHA in the aerosols of three brands of e-cigarettes has been carried out. These included two devices with horizontal heating coil configurations as well as one with a sub-ohm resistance vertical heating coil. In order to understand and begin to address the origin of DHA and related aerosol products, the wicking properties of the three e-cigarettes were compared. DHA levels were analyzed by a combination of GS/MS and 1H NMR. DHA was found in all three e-cigarettes, with substantially less in the sub-ohm, vertical coil device as compared to the horizontal coil devices (e.g., 0.088 μg/puff vs. 2.29 μg/puff, respectively). Correspondingly, the temperature of the wet layer of the wick for the vertical coil was relatively stable, compared to the wicks for the horizontal coils, upon increasing battery power output. This result is in agreement with prior studies of e-cigarette wicking efficiency and aerosol toxin formation. The temperature measurements reported are a simple means for comparing devices with different design properties during operation.

A simple predictive model for estimating relative e-cigarette toxic carbonyl levels

“…At a temperature of 318°C, formaldehyde, acetaldehyde, acetone and acrolein were generated [ 18 ]. In the current study, we expand on our previous report on e-cigarette wicking properties [ 7 ], wherein we had shown that the stability of the wick temperature during aerosolization served as a predictor of the degree of PG/GL degradation.…”

“…Factors such as puff volume [ 4 ], e-liquid consumed [ 5 ] and power output [ 6 ] are known to correlate to toxin levels intra-device; however, methods for understanding inter-device levels are still needed. For instance, ten times lower toxin levels were reported in the aerosols produced by an e-cigarette operated at 50 W compared to a different e-cigarette operated at 10 W [ 7 ].…”

Electronic nicotine delivery system design and aerosol toxicants: A systematic review

“…Vreeke et al [35] observed that acrolein and acetaldehyde remained below the limit of detection when power increased from 55 W to 65 W on a sub-ohm (<1 ohm resistance) heating coil, but these toxicants increased when power increased from 9 W to 11 W on a supra-ohm (>1 ohm resistance) heating coil. Vreeke et al [34] found that device temperature increases with increasing power and corresponds directly to dihydroxyacetone (DHA) production. Pankow et al [50] observed that benzene concentrations in aerosol increased with increasing wattage from 6 W to 13 W on one device, but remained undetectable when wattage increased from 6 W to 20 W on a different device.…”

“…Pankow et al [50] reported that benzene concentrations were largely undetectable in an ENDS with a single vertical coil with a cotton wick, but were more readily detected with a single horizontal coil with a silica wick. Vreeke et al [34] observed that aerosol concentrations of DHA were directly proportional to the mass of aerosolized VG:PG, but a vertical coil produced less DHA than a horizontal coil.…”

Aerosol droplet-size distribution and airborne nicotine portioning in particle and gas phases emitted by electronic cigarettes

“…Other chemical compounds are generally added to the e-liquid formulation, such as nicotine and (in smaller quantities) flavor, water, and ethanol primarly 2 – 4 . The chemical composition of the aerosol produced by the EC depends on several parameters such as the delivered power, the ingredients of the e-liquid, or the puffing conditions, number of puffs, volume and duration, and features of airflow, among others 5 – 7 . The aerodynamic diameter of the airborne droplets generated by ECs has a noticeable impact on the nicotine delivery to the vapers.…”