Table 1

The top 25 most frequently added flavouring ingredients in e-liquids from the EU-CEG dataset

Flavouring ingredientPrevalence (% of total e-liquids)Median concentration (mg/10 mL)Flavour descriptionGHS code*
1Vanillin35.27.0Sweet, powerful, creamy, vanilla-like.H317 and H319.
2Ethyl maltol32.05.9Sweet, fruity-caramellic, cotton candy.H302.
3Ethyl butyrate28.43.6Ethereal, fruity with buttery-pineapple-banana, ripe fruit and juicy notes.H226.
4Ethyl acetate23.21.1Ethereal, sharp, wine-brandy-like.H225, H319 and H336.
5Maltol22.81.3Sweet, fruity, berry, strawberry, caramellic.H302.
6Ethyl vanillin19.46.8Intense, sweet, creamy, vanilla-like.H302, H315, H319, H335 and H412.
7Furaneol19.32.0Fruity, caramelised, roasted, pineapple-strawberry.H302, H317 and H319.
8Methyl cyclopentenolone18.32.0Very strong, caramellic-maple, lovage.n/a
10Cis-3-hexenol17.81.5Strong, fresh, green, grassy.H226 and H319.
11Isoamyl acetate16.32.3Sweet, fruity, banana, pear.H226.
12Ethyl 2-methyl butyrate16.02.2Strong, green, fruity, apple with strawberry notes.H226.
13Acetic acid15.71.2Pungent, sour, acid, vinegar.H226 and H314.
14Butyric acid15.00.8Tropical fruity floral, plum, apricot-pear-like.H314.
15Linalool14.50.9Sweet floral-woody with slight citrus notes.H315, H317 and H319.
16Benzyl alcohol14.23.3Faint, sweet, almond fruity, somewhat chemical.H302 and H332.
17Ethyl hexanoate13.60.5Strong, fruity, pineapple, banana with strawberry, pear and tropical notes.H226.
18Benzaldehyde12.40.3Bitter almond oil, sweet cherry.H302.
19Menthol12.118.4String trigeminal cooling sensation with a slight mint note.H315 and H319.
20Isoamyl isovalerate11.50.8Fruity, green-apple, pineapple, tropical, mango, apricot, cognac.H411.
21δ-Decalactone11.20.3Sweet, creamy, milky, peach, nut, buttery.n/a
22Hexanoic acid11.10.4Heavy, fatty, cheesey-sweaty.H311, H314 and H318.
23Ethyl propionate10.90.5Strong, ethereal, fruity, rum-like.H225.
24γ-Undecalactone10.90.4Strong fatty, peach-apricot.H411 and H412.
25Hexyl acetate10.31.0Sweet, fruity, pear-apple, green, banana.H411.
  • Prevalence is reported as the number of e-liquids containing the respective flavouring as percentage of the total number of e-liquids. Flavour descriptions were retrieved from a commercial flavour database.34 GHS codes were retrieved from PubChem (

  • *GHS=Globally Harmonized System of Classification and Labeling of Chemicals; hazard statements can be found at

  • EU-CEG, European Common Entry Gate.