Does “Dry hit” vaping of vitamin E acetate contribute to EVaLI? Simulating toxic ketene formation during e-cigarette use.

Vitamin E acetate (VEA) is strongly linked to the outbreak of electronic-cigarette or vaping
product use-associated lung injury (EVALI). It has been proposed that VEA decomposition
to ketene–a respiratory poison that damages lungs at low ppm levels–may play a role in
EVALI. However, there is no information available on the temperature at which VEA decomposes
and how this correlates with the vaping process. We have studied the temperaturedependent
kinetics of VEA decomposition using quantum chemical and statistical mechanical
modelling techniques, developing a chemical kinetic model of the vaping process. This
model predicts that, under typical vaping conditions, the use of VEA contaminated e-cigarette
products is unlikely to produce ketene at harmful levels. However, at the high temperatures
encountered at low e-cigarette product levels, which produce ‘dry hits’, ketene
concentrations are predicted to reach acutely toxic levels in the lungs (as high as 30 ppm).
We therefore hypothesize that dry hit vaping of e-cigarette products containing VEA contributes
to EVALI.

Narimani M, da Silva G. Does “Dry hit” vaping of vitamin E acetate contribute to EVaLI? Simulating toxic ketene formation during e-cigarette use. PloS one. 2020;15(9):1. doi:10.1371/journal.pone.0238140