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

Abstract

E-cigarette devices are wide ranging, leading to significant differences in levels of toxic carbonyls in their respective aerosols. Power can be a useful method in predicting relative toxin concentrations within the same device, but does not correlate well to inter-device levels. Herein, we have developed a simple mathematical model utilizing parameters of an e-cigarette’s coil and wick in order to predict relative levels of e-liquid solvent degradation. Model 1, which is coil length/(wick surface area*wraps), performed in the moderate-to-substantial range as a predictive tool (R 2 = 0.69). Twelve devices, spanning a range of coil and wick styles, were analyzed. Model 1 was evaluated against twelve alternative models and displayed the best predictability. Relationships that included power settings displayed weak predictability, validating that power levels cannot be reliably compared between devices due to differing wicking and coil components and heat transfer efficiencies.

Chemical characterisation of the vapour emitted by an e-cigarette using a ceramic wick-based technology

“…Poor wicking efficiency may lead to a dry wick and overheated e-liquid (dry puff), which promotes the formation of carbonyls and other toxic compounds 2 , 10 , 13 , 15 . Coil location, orientation, resistance and wick material, as well as power output, have been shown to affect carbonyl generation significantly 13 , 15 , 86 . E-liquid physical properties are also important in carbonyl formation 15 , 47 , 84 , 86 .…”

“…Flavourings may also contribute to the formation of carbonyls, as well as the characteristics of the e-cigarette devices, especially the applied voltage, coil resistance and wicking material [47][48][49]86,87 . Poor wicking efficiency may lead to a dry wick and overheated e-liquid (dry puff), which promotes the formation of carbonyls and other toxic compounds 2,10,13,15 . Coil location, orientation, resistance and wick material, as well as power output, have been shown to affect carbonyl generation significantly 13,15,86 .…”

“…Power levels that produce aerosol beyond the ability of the wick to resupply the liquid to the coil may result in overheating of the atomizer coil and consequently overheating of the e-liquid 10 , 11 . Different types of wicking material, varying in size and shape, have been used in e-cigarettes 3 , 13 . Silica was commonly the first material to be used as a wick, followed by cotton and ceramic 3 , 13 – 15 .…”

“…Different types of wicking material, varying in size and shape, have been used in e-cigarettes 3 , 13 . Silica was commonly the first material to be used as a wick, followed by cotton and ceramic 3 , 13 – 15 . Cotton has good wicking properties but is less thermally stable than silica 14 , 16 , 17 , while ceramic is chemically stable and heat-resistant 18 .…”

Thermography of cannabis extract vaporization cartridge heating coils in temperature- and voltage-controlled systems during a simulated human puff

“…Published research on both cannabis and nicotine vaporization products has demonstrated that higher concentrations of undesirable and potentially toxic thermal degradation products are produced as temperature (or device power output) increases [7,[27][28][29]. These thermal degradants include aromatics (e.g., benzene, styrene), carbonyl compounds (e.g., formaldehyde, methacrolein), and others (e.g., polyaromatic hydrocarbons, carbon monoxide) that should be avoided due to the potential for toxicity.…”