Vaped humectants in E-Cigarettes are a Source of Phenols.

Introduction:
This text describes a study that aimed to detect and quantify phenolic compounds in electronic cigarette (ECIG) aerosols using a novel analytical method. The study also examined the influence of various operating parameters, such as power, puff duration, PG/VG ratios, nicotine benzoate concentrations, and flow rates, on phenol formation.

Key Points:

* The study developed a robust analytical method for isolating and quantifying phenol emissions in ECIG aerosols.
* Phenol emissions were found to be independent of the nicotine benzoate concentration but significantly correlated with the PG/VG ratio and operating conditions that lead to higher temperature and greater thermal degradation.
* The phenol profile in the ECIG aerosol was dominated by the unsubstituted phenol, which reached comparable levels to those of IqOS, combustible cigarettes, and waterpipe.
* Low levels of more toxic phenolic compounds, like catechol and hydroxyquinone, were quantified in ECIG aerosols.
* Emission of toxicants was presented as the yield per unit of time, or flux (μg/sec), which is more suitable for inter-study and inter-product comparison.
* The study demonstrated that phenols, which are not present in the simple solution of nicotine benzoate dissolved in mixtures of PG/VG, are formed upon vaping.
* The levels of unsubstituted phenol emitted by ECIGs were found to be comparable to IqOS, waterpipe, and combustible cigarettes under realistic use conditions.

Main Message:
The study highlights the importance of developing robust analytical methods for isolating and quantifying toxicants in ECIG aerosols. The findings demonstrate that phenols, which are known to be harmful, are formed upon vaping and that their emission is dependent on the operating conditions and PG/VG ratio. The study also emphasizes the need to present toxicant emissions as the yield per unit of time, or flux, to enable meaningful comparisons between different products and studies. Overall, the study provides valuable information for regulators and policymakers regarding the potential health risks associated with ECIG use.

El-hage R, El-hellani a, Salman R, Talih S, Shihadeh a, Saliba Na. Vaped humectants in E-Cigarettes are a Source of Phenols. Chemical research in toxicology. 2020;33(9):2374-2380. doi:10.1021/acs.chemrestox.0c00132