Unveiling the Chemistry of E-Cigarettes: What’s Inside Your Vape

Chemia Naissensis Volume 7, No.2 (2025) (стр. 55-66)   

АУТОР(И) / AUTHOR(S): Milijana M. Zlatković and Mihajlo A. Halilović 

 

Download Full Pdf   

DOI: 10.46793/ChemN7.2.55Z

САЖЕТАК / ABSTRACT:

Smoking tobacco represents one of the most harmful habits for health, causing addiction, a series of somatic problems ranging from allergic reactions to cardiovascular diseases and lung cancer. Recently, electronic cigarettes (e-cigarettes) are increasingly being promoted as a healthier alternative to smoking. Though e-cigarettes have been marketed as safer alternatives to traditional tobacco products, the composition of e-liquids, the substances inhaled during vaping, require critical evaluation. E-liquids typically contain nicotine, propylene glycol, glycerol, flavoring agents, and other additives. However, studies have identified harmful constituents, including tobacco-specific nitrosamines (TSNAs), a group of carcinogenic compounds found in tobacco and tobacco smoke, volatile organic compounds (VOCs), heavy metals, and carbonyl compounds, which can form during heating.

Nicotine, a primary component of most e-liquids, poses addiction risks and cardiovascular effects. TSNAs and VOCs, even in trace amounts, are known carcinogens. Heavy metals (lead, cadmium, and nickel) released from e-cigarette components raise toxicological concerns. It’s important to note that when inhaled, flavoring agents, often considered safe for ingestion, may have adverse respiratory effects, underscoring the need for caution.

Despite their popularity, e-cigarettes’ long-term health impacts remain largely unknown, complicating public health assessments (Omaiye et al., 2020). The diverse chemical composition of e-liquids, combined with the alarming lack of strict quality standards, raises additional concerns. Present review emphasizes the urgent need for comprehensive research into the components of e- liquids and their potential health effects. Regulatory frameworks should introduce mandatory declarations of ingredient and product safety to reduce the risks associated with e-cigarette use. Addressing these gaps is essential to inform consumers, guide policymakers, and ensure public health protection amidst the growing popularity of e-cigarettes.

КЉУЧНЕ РЕЧИ / KEYWORDS:

e-cigarettes, nicotine, tobacco-specific nitrosamines, volatile organic compounds, carbonyls, heavy metals

ПРОЈЕКАТ/ ACKNOWLEDGEMENT:

ЛИТЕРАТУРА / REFERENCES:

  • Bahl V, Lin S, Xu N, Davis B, Wang YH, Talbot P. (2012) Comparison of electronic cigarette refill fluid cytotoxicity using embryonic and adult models. Reprod Toxicol, 34, 529–537.
  • Bullen C, Williman J, Howe C, et al. (2013) Study protocol for a randomised controlled trial of electronic cigarettes versus nicotine patch for smoking cessation. BMC Public Health, 13, 210.
  • Burstyn I. (2014) Peering through the mist: systematic review of what the chemistry of contaminants in electronic cigarettes tells us about health risks. BMC Public Health, 14:18.
  • Caponnetto P, Campagna D, Cibella F, et al. (2013a) Efficiency and safety of an electronic cigarette (ECLAT) as tobacco cigarettes substitute: a prospective 12-month randomized control design study. PLoS One, 8, 1–12. doi: 10.1371/journal.pone.0066317
  • Caponnetto P, Russo C, Bruno CM, Alamo A, Amaradio MD, Polosa R. (2013b) Electronic cigarette: a possible substitute for cigarette dependence. Monaldi Arch Chest Dis., 79, 12–19.
  • Cheah NP, Chong NW, Tan J, Morsed FA, Yee SK. (2014) Electronic nicotine delivery systems: regulatory and safety challenges: Singapore perspective. Tob Control, 23, 119–125.
  • Davis B, Dang M, Kim J, Talbot P. (2014) Nicotine concentrations in electronic cigarette refill and do-it-yourself fluids. Nicotine Tob Res. doi:10.1093/ntr/ntu080
  • Environmental Protection Agency (EPA) (2014) Method 8260B/US, volatile organic compounds by gas chromatography/mass spectrometry (GC/MS) http://www.epa.gov/osw/hazard/testmethods/
  • Etter JF, Bullen C, Flouris AD, Laugesen M, Eissenberg T. (2011) Electronic nicotine delivery systems: a research agenda. Tob Control, 20, 243–248.
  • Etter JF, Zäther E, Svensson S. (2013) Analysis of refill liquids for electronic cigarettes. Addiction, 08, 1671–1679.
  • FDA (2009) Laboratory analysis of electronic cigarettes conducted by FDA. http://www.fda.gov/NewsEvents/PublicHealthFocus/ucm173146.
  • Farsalinos KE, Romagna G, Tsiapras D, Kyrzopoulos S, Voudris V. (2013a) Evaluating nicotine levels selection and patterns of electronic cigarette use in a group of “vapers” who had achieved complete substitution of smoking. Subst Abuse., 7, 139–146.
  • Farsalinos KE, Romagna G, Tsiapras D, Kyrzopoulos S, Voudris V. (2013b) Evaluation of electronic cigarette use (vaping) topography and estimation of liquid consumption: implications for research protocol standards definition and for public health authorities’ regulation. Int J Environ Res Public Health, 10, 2500–2514.
  • Goniewicz ML, Hajek P, McRobbie H. (2014a) Nicotine content of electronic cigarettes, its release in vapour and its consistency across batches: regulatory implications. Addiction, 109, 500–507.
  • Goniewicz ML, Knysak J, Gawron M, et al. (2014b) Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tob Control, 23, 133–139.
  • IARC (2007) Some tobacco-specific N-nitrosamines. IARC Monogr. 89, 421–456. http://monographs.iarc.fr/ENG/Monographs/vol89/mono89-7.pdf.
  • Kim HJ, Shin HS. (2013) Determination of tobacco-specific nitrosamines in replacement liquids of electronic cigarettes by liquid chromatography-tandem mass spectrometry. J Chromatogr A, 1291, 48–55.
  • Kosmider L, Sobczak A, Fik M, et al. (2014) Carbonyl compounds in electronic cigarette vapors- effect of nicotine solvent and battery output voltage. Nicotine Tob Res, 16, 1319–1326. doi:10.1093/ntr/ntu078
  • Krüsemann, E. J. Z., Havermans, A., Pennings, J. L. A., de Graaf, K., Boesveldt, S., Talhout, R., et al. (2021). Comprehensive Overview of Common E-Liquid Ingredients and How They Can Be Used to Predict an E-Liquid’s Flavour Category, Tob. Control, 30, 185. doi:10.1136/tobaccocontrol-2019-055447
  • Laugesen M. (2008) Safety report on the Ruyan® e-cigarette cartridge and inhaled aerosol. Christchurch,  New Zealand: Health New Zealand Ltd. http://www.healthnz.co.nz/2ndSafetyReport_9Apr08.pdf.
  • Lim HH, Shi HS. (2013) Measurement of aldehydes in replacement liquids of electronic cigarettes by headspace gas chromatography-mass spectrometry. B Kor Chem Soc, 34, 2691–2696.
  • Manzoli L, La Vecchia C, Flacco ME, et al. (2013) Multicentric cohort study on the long-term efficacy and safety of electronic cigarettes: study design and methodology. BMC Public Health, 13, 883.
  • Moran MJ, Hamilton PA, Zogorski JS. (2006) Volatile organic compounds in the Nation’s ground water and drinking-water supply wells-A Summary. U.S. Geological Survey Fact Sheet, 6. http://water.usgs.gov/nawqa/vocs/national_assessment/.
  • O’Connor RJ. (2012) Non-cigarette tobacco products: what have we learned and where are we headed? Tob Control, 21, 181–190.
  • Omaiye, E. E., Luo, W., McWhirter, K. J., Pankow, J. F., and Talbot, P. (2020). Electronic Cigarette Refill Fluids Sold Worldwide: Flavor Chemical Composition, Toxicity and Hazard Analysis, Chem. Res. Tox, 33, 2972. doi:10.1021/acs.chemrestox.Oc00266.
  • Polosa R, Rodu B, Caponnetto P, Maglia M, Raciti C. (2013) A fresh look at tobacco harm reduction: the case for the electronic cigarette. Harm Reduct J, 10, 19.
  • Schober W, Szendrea K, Matzea W, et al. (2013) Use of electronic cigarettes (e-cigarettes) impairs indoor air quality and increases FeNO levels of e-cigarette consumers. Int J Hyg Environ Health, 217, 628–637. doi:10.1016/j.ijheh.2013.11.003
  • Trehy ML, Ye W, Hadwiger ME, et al. (2011) Analysis of electronic cigarette cartridges, refill solutions, and smoke for nicotine and nicotine related impurities. J Liq Chromatogr Relat Technol, 34, 1442–1458.
  • Uchiyama S, Ohta K, Inaba Y, Kunugita N. (2013) Determination of carbonyl compounds generated from the E-cigarette using coupled silica cartridges impregnated with hydroquinone and 2,4-dinitrophenylhydrazine, followed by high-performance liquid chromatography. Anal Sci, 29, 1219–1222.
  • Uchiyama, S., Noguchi, M., Sato, A., Ishitsuka, M., Inaba, Y., and Kunugita, N. (2020). Determination of Thermal Decomposition Products Generated from E-Cigarettes, Chem. Res. Toxicol, 33 (2), 576–583. doi:10.1021/acs.chemrestox.9b00410
  • Westenberger, B.J. (2009) Evaluation of e-cigarettes; FDA, 1-8  http://www.fda.gov/downloads/drugs/scienceresearch/ucm173250.pdf.
  • Williams M, Villarreal A, Bozhilov K, Lin S, Talbot P. (2013) Metal and silicate particles including nanoparticles are present in electronic cigarette cartomizer fluid and aerosol. PLoS One, 8, 3.
  • Yildiz D. (2004) Nicotine, its metabolism and an overview of its biological effects. Toxicon, 43, 619–632.
  • Zhao, S., Zhang, X., Wang, J. et al. (2023) Carcinogenic and non-carcinogenic health risk assessment of organic compounds and heavy metals in electronic cigarettes. Sci Rep, 13, 16046. https://doi.org/10.1038/s41598-023-43112-y