Health Hazards of E-Cigarettes and Heated Tobacco Products: a Comprehensive Analysis of Hazardous Substances and Regulatory Gaps

Introduction During use of Electronic Cigarettes (ECs) and Heated Tobacco Products (HTPs), their ingredients and products formed during heating are aerosolized and inhaled. Hazard information is often unavailable. Our objective was to identify and classify substances in the ingredients or emissions of ECs and HTPs, based on scientific hazard classifications. Methods Ingredient data were collected from the European Union Common Entry Gate (EU-CEG), a mandatory notification system for tobacco and related products in the EU. Substances in EC or HTP emissions were identified with a systematic literature review and classified into three categories based on existing health hazard classifications. Category 1 substances (highest potential health hazard) were regarded as high-priority substances for research and quantification. Categories 2 and 3 included potentially harmful substances and substances lacking sufficient toxicological data respectively. Results 134 of the 1740 identified substances were classified in Category 1. Several substances possess Carcinogenic, Mutagenic, or Reprotoxic properties, prohibited as tobacco additives. Most substances lacked sufficient toxicity data and were classified in Category 3. Conclusion Our classification can be used for monitoring and enforcement, ensuring proactive management of potential risks. Therefore, we recommend strengthening the enforcement of existing bans. Implications This study identifies and classifies 1740 substances found in the ingredients and emissions of ECs and HTPs, including, 134 hazardous chemicals, among which are carcinogens, mutagens and reproduction toxicants. This indicates regulatory gaps and the need for stricter enforcement of existing bans. The findings provide a valuable tool for policymakers and public health professionals for monitoring and mitigating risks.