Chemical and Toxicological Characterization of Vaping Emission Products from Commonly Used Vape Juice Diluents

Abstract

Recent reports have linked severe lung injuries and deaths to the use of e-cigarettes and vaping products. Nevertheless, the causal relationship between exposure to vaping emissions and the observed health outcomes remains to be elucidated. Through chemical and toxicological characterization of vaping emission products, this study demonstrates that during vaping processes, changes in chemical composition of several commonly used vape juice diluents (also known as cutting agents) lead to the formation of toxic byproducts, including quinones, carbonyls, esters, and alkyl alcohols. The resulting vaping emission condensates cause inhibited cell proliferation and enhanced cytotoxicity in human airway epithelial cells. Notably, substantial formation of the duroquinone and durohydroquinone redox couple was observed in the vaping emissions from vitamin E acetate, which may be linked to acute oxidative stress and lung injuries reported by previous studies. These findings provide an improved molecular understanding and highlight the significant role of toxic byproducts in vapingassociated health effects.

Simultaneous Temperature Measurements and Aerosol Collection During Vaping for the Analysis of Δ9-Tetrahydrocannabinol and Vitamin E Acetate Mixtures in Ceramic Coil Style Cartridges

“…Additionally, we identified compounds consistent with the production of ketene gas by proposed pathways for VEA decomposition, (Wu and O'Shea, 2020) including detection of a substance that, based on exact mass measurement, was consistent with the previously undetected quinone methide ATMMC. Although ketene itself was not detected by the methods employed in this study, detection of the previously identified VEA degradants (Jiang et al, 2020;Mikheev et al, 2020;Wu and O'Shea, 2020)in the vaped condensates collected from the THC/VEA mixtures indicates that, at least under some conditions that consumers may encounter, pulmonary toxins may be produced from vaping of mixtures containing VEA in ceramic coil cartridges.…”

“…This study was performed using a device designed for nicotine vaping, producing very high power using a sub-Ohm (0.25 Ω) resistance coil ( Wu and O’Shea, 2020 ), in contrast to the ceramic wick cartridges commonly used for vaping of THC concentrates, with typical coil resistances in the 1.3–2.2 Ω range. One study has identified and quantitated the VEA decomposition products duroquinone and durohydroquinone in a vaporized VEA solution in one 1.4 Ω ceramic wick cartridge operated at 3.6 V ( Jiang et al, 2020 ). Another study on VEA aerosolization monitored the temperature of a cartridge with a stainless steel coil by IR temperature measurement through a custom designed cell following the removal of the tank and found temperatures from 500–600°C, though no temperature data on ceramic coil cartridges was provided.…”

A Retrospective Analysis of Chemical Constituents in Regulated and Unregulated E-Cigarette Liquids

“…MCT aerosols were found to contain alkyl alcohols, which are surfactant-like and can produce cytotoxic effects. MCTs and PEG both produce harmful carbonyls when aerosolized (Troutt and DiDonato, 2017;Jiang et al, 2020). PEG was found to produce levels of formaldehyde that neared those seen by traditional combustion cigarettes, with one puff exposing the user to 1.12% of the daily exposure limit set forth by the United States Occupational and Safety Health Administration (OSHA) (Troutt and DiDonato, 2017).…”

“…Though considered harmless based on years of use in food and medicine, use of these chemicals in e-cigs and vaporizers is not inherently safe. Studies have demonstrated that when heated to high temperatures, like those of a heated e-cig coil, PG and VG can produce carbonyls such as formaldehyde and acetaldehyde (Kosmider et al, 2014;Geiss et al, 2016;Troutt and DiDonato, 2017;Qu et al, 2019;Jiang et al, 2020). Device settings have been found to directly affect the production of these harmful chemicals, and therefore may lead to the risks of increased exposures to these carcinogens, as carbonyl formation has been shown to increase directly with increasing battery output voltages (Kosmider et al, 2014;Qu et al, 2019).…”

“…Though VEA was not identified in any samples, VE was identified in multiple cannabinoid-containing products. Both VE and VEA produce quinone-like compounds, which can produce reactive oxygen species that increase cytotoxicity (Jiang et al, 2020).…”