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TSRC, Tob. Sci. Res. Conf., 2023, 76, abstr. 35 (also presented at CORESTA SSPT2023)

Application of the human health risk assessment process for the evaluation of electronic cigarettes

BERNAL A.(1); LIU C.(2); JOHNSON C.(3); YOUNG R.(3)
(1) Toxcreative, Laguna Hills, CA, USA; (2) RiskWise Soultions, Princton, NJ, USA; (3) Bibra Toxicology Advice & Consulting, Wallington, UK

Electronic cigarettes (e-cigarettes) aerosolize a nicotine-containing e-liquid that is inhaled by the consumer. Compared to combustible cigarette smoke, e-cigarettes typically produce significantly lower levels of inhaled toxicants. The aerosol mixture delivered to the consumer from an e-cigarette contains several components, such as e-liquid ingredients, thermal decomposition/reaction products, and device-derived materials. Exposure to this inhaled mixture is not without health risks that must be evaluated. The human health risk assessment process provides a systematic approach to evaluate the potential adverse effects associated with chemical exposures. However, a comprehensive risk assessment framework for evaluating e-cigarettes has not previously been developed due to the complex nature of the aerosol mixture, variability of toxicological data for the inhaled ingredients (e.g., nicotine, excipients, and flavoring compounds), thermal decomposition/reaction products (e.g., harmful and potentially harmful constituents and non-targeted analytes), and device-derived materials (e.g., leachables), as well as a lack of accepted standards. The objective of this work is to propose a suitable and pragmatic risk assessment process that can be adopted to evaluate the health effects potentially caused by exposure to e-cigarette aerosol mixtures. The framework presented here considers the variability in toxicological data and toxicological prioritization for each aerosol component to incorporate appropriate analytical characterization methods, tools for hazard identification and dose-response assessment, best practices for exposure estimation, and regulatory standards for quantitative and/or qualitative risk characterization approaches. Overall, with consideration of other sources of nonclinical data, a systematic, weight-of-evidence risk assessment process is established for the whole aerosol. This comprehensive framework is the first to be presented for any tobacco product and can be utilized to support risk assessment standardization, product development, regulatory submissions, and inform regulatory decisions.