quantitative insights into major constituents contained in or released by electronic cigarettes: Propylene glycol, vegetable glycerin, and nicotine.

Introduction:
This article provides quantitative insights into the major constituents contained in or released by electronic cigarettes, specifically propylene glycol, vegetable glycerin, and nicotine. The study analyzes liquid and aerosol samples from 50 commercial electronic cigarette products to accurately quantify the three major constituents and learn more about the actual composition of electronic cigarettes. The results offer valuable information about the differences in the amount of PG, VG, and nicotine before and after the consumption of electronic cigarettes in relation to key variables such as voltage.

Key points:

* The major components in liquid and aerosol samples of electronic cigarettes were analyzed.
* The measured nicotine contents were 1.2 times higher than those provided by the manufacturers.
* The consumption rate of PG and nicotine decreased with the increasing voltage from 3.4 to 4.8 V.
* The amounts of PG/VG generated from electronic cigarettes are much larger than other comparable products.
* The recovery rates of aerosol by the Cambridge filter used in this study are generally stable, even if the voltage of the electronic cigarette changes.
* The amount of liquid consumed varies by product, but the differences decrease as the voltage of the electronic cigarette increases.
* The amount of nicotine, PG, and VG in the tested 50 E-liquid products was different for each product.
* The study found that the nicotine levels measured mostly differed from those provided by the manufacturers and were significantly higher than labeled, except for EC-15, 18, 20, 41, and 50.

Main message:
The study highlights the importance of accurate labeling and regulation of electronic cigarettes. The results show that the nicotine levels in electronic cigarettes can be higher than labeled, and the amount of nicotine, PG, and VG consumed can vary significantly between products. This variation in composition and the effect of voltage on consumption rates can impact the delivery rate of these constituents to the human body. Therefore, it is crucial to establish proper regulations and labeling requirements for electronic cigarettes to ensure the safety and informed use of these products.

Lee YJ, Na CJ, Botao L, Kim Kh, Son YS. quantitative insights into major constituents contained in or released by electronic cigarettes: Propylene glycol, vegetable glycerin, and nicotine. The Science of the total environment. 2020;703:134567. doi:10.1016/j.scitotenv.2019.134567