Article Text

Flavour chemicals, synthetic coolants and pulegone in popular mint-flavoured and menthol-flavoured e-cigarettes
  1. Esther E Omaiye1,
  2. Wentai Luo2,
  3. Kevin J McWhirter3,
  4. James F Pankow2,
  5. Prue Talbot1
  1. 1 Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, USA
  2. 2 Department of Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
  3. 3 Civil and Environmental Engineering, Portland State University, Portland, Oregon, USA
  1. Correspondence to Dr Prue Talbot, Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, USA; talbot{at}ucr.edu

Abstract

Background The Food and Drug Administration (FDA) has recently banned flavours from pod-style electronic cigarettes (e-cigarettes), except for menthol and tobacco. JUUL customers have quickly discovered that flavoured disposable e-cigarettes from other manufacturers, such as Puff, are readily available. Our goal was to compare flavour chemicals, synthetic coolants and pulegone in mint-flavoured/menthol-flavoured e-cigarettes from JUUL and Puff, evaluate the cytotoxicity of the coolants and perform a cancer risk assessment for pulegone, which is present in both JUUL pods and disposable Puff products.

Methods Identification and quantification of chemicals were performed using gas chromatography/mass spectrometry. Cytotoxicity of the coolants was evaluated with BEAS-2B cells using the MTT 3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyltetrazolium bromide assay. The cancer risk of pulegone was calculated using the margin of exposure (MOE).

Results Menthol was the dominant flavour chemical (>1 mg/mL) in all products from both manufacturers. Minor flavour chemicals (<1 mg/mL) differed in the JUUL and Puff fluids and may produce flavour accents. The concentrations of WS-3 and WS-23 were higher in Puff than in JUUL. WS-23 was cytotoxic in the MTT assay at concentrations 90 times lower than concentrations in Puff fluids. The risk of cancer (MOE<10 000) was greater for mint than for menthol products and greater for Puff than for JUUL.

Conclusions Switching from flavoured JUUL to Puff e-cigarettes may expose users to increased harm due to the higher levels of WS-23 and pulegone in Puff products. Cancer risk may be reduced in e-cigarettes by using pure menthol rather than mint oils to produce minty-flavoured e-cigarette products.

  • carcinogens
  • electronic nicotine delivery devices
  • toxicology
  • global health

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information. All relevant data are included in the submitted manuscript.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.

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Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information. All relevant data are included in the submitted manuscript.

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Footnotes

  • Contributors EEO and PT formed the conception and design of the study. WL, KJMcW and JFP were involved in the gas chromatography–mass spectrometry analysis. EEO performed the cell culture experiment. EEO, WL, KJMcW and PT were involved in the data analysis and interpretation. EEO and PT drafted the manuscript. All authors critically reviewed, edited and approved the final manuscript.

  • Funding Research reported in this publication was supported by grant R01ES029741-01 from the National Institute of Environmental Health Sciences and the Food and Drug Administration Centre for Tobacco Products, and a Predoctoral Fellowship from the UCR Graduate Division to Esther Omaiye.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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