Influence of Nitrite on Formation of Tobacco-Specific Nitrosamines in Electronic Cigarette Liquids and aerosols.

Introduction:
This article discusses a study on the influence of nitrite on the formation of tobacco-specific nitrosamines (TSNas) in electronic cigarette (e-cigarette) liquids and aerosols. The study aimed to understand the drivers behind the potential formation of TSNas in e-cigarette aerosols and e-liquids and to evaluate pathways for TSNa formation.

Key Points:

* Nitrite can react with nicotine and minor alkaloids to form TSNas in e-liquids.
* TSNa levels in e-liquids increased over time and the process was accelerated by elevated temperature.
* TSNas formed during aerosol generation when nitrite was present in the corresponding e-liquids.
* Commercial e-cigarette products that showed higher levels and formation of TSNas were observed to contain nitrite and minor alkaloid impurities in the corresponding e-liquids.
* Nitrite and minor alkaloids in e-liquids can facilitate the formation of TSNas both in e-liquids and the aerosol of e-cigarette products.
* Nitrite was present in the e-liquid of some commercial e-cigarette products, and detectable levels of TSNas were found in the aerosols generated from vaporizing the e-liquid.
* Commercial e-cigarette products that contained e-liquids with high levels of nitrite produced aerosols that had significantly higher TSNa levels compared to the corresponding e-liquid.

Main Message:
The study provides valuable information about drivers for TSNa formation in e-liquids and e-cigarette aerosols that may be applied to the evaluation and quality assurance of e-cigarette products. The presence of nitrite in the e-liquid can lead to the formation of TSNas during aerosol generation, and e-liquids used in the products must be devoid of any nitrite impurity to prevent TSNa formation. The study highlights the importance of monitoring and regulating the quality of e-cigarette products to ensure the safety of their use.

Jin XC, Wagner Ka, Melvin MS, et al. Influence of Nitrite on Formation of Tobacco-Specific Nitrosamines in Electronic Cigarette Liquids and aerosols. Chemical research in toxicology. 2022;35(5):782-791. doi:10.1021/acs.chemrestox.1c00417