A study conducted by Konstantinos E. Farsalinos - Department of Cardiology, Onassis Cardiac Surgery Center, Laboratory of Molecular Biology and Immunology, Department of Pharmacy, National School of Public Health, Greece - and George Lagoumintzis - Laboratory of Molecular Biology and Immunology, University of Patras, Greece - published in Harm Reduction Journal on 25 July 2019 evaluates the main flavors used in electronic cigarette e liquids available in Europe.

Scientific studies on eliquid flavors multiply

  This latest study echoes another analysis by Constantine Vardavas, a medical epidemiologist specializing in research methods for tobacco control and published in the European Respiratory Journal under the title of:

Respiratory irritants in e-cigarette refill liquids across nine European countries: a threat to respiratory health? "

In this study, Dr. Vardavas concluded, after analysis of 122 samples of European e juices, the presence of numerous irritating additives, such as methyl cyclopentanolone, acetyl pyrazine, ethyl vanillin, menthol.

The last study by Dr. Farsalinos that interests us here was conducted in opposition to the methodology applied by Dr. Vardavas to reach his conclusions.

Conduct scientific research in the context of vaping

  Dr. Vardavas' methodology is to have assessed the toxicity thresholds of the substances based only on the pre-established classification of the European Chemicals Agency and a simple analysis based on a single flavor and its maximum dosage.

However, vapers know that they use most of the time mixtures of flavors that make up an e liquid recipe.

Dr. Farsalinos' study therefore relies on mixtures of flavors diluted in propylene glycol and vegetable glycerine to obtain a vape juice with maximum dosage of each aromatic component.

The chemicals tested are:

- menthol: mint taste
- ethyl maltol: caramelized taste
- linalool: woody taste
- methyl cyclopentenolone: ​​nutty caramel taste
- β-Damascone: fruit taste
- ethyl vanillin: vanilla flavor
- β-Ionone: fruit taste
- acetyl pyrazine: roasted taste
- α-Ionone: fruit taste
- ethyl hexanoate: fruit taste
- 2,5 dimethylpyrazine: hazelnut chocolate taste
- α-Damascone: fruity taste
- 3,4 Dimethoxy-benzaldehyde: vanilla taste
- Limonene: lemon taste, citrus

All these chemical compounds are classified safe for human health but irritating, some for the skin, others for the eyes or the respiratory system.
Environmental toxicity is also noted for some.

flavor chemistry and side effects

The analyzes conducted by Dr. Farsalinos and his team show that only methyl cyclopentenolone has a real toxicity at very high concentration.

Methyl cyclopentenolone is a broad-spectrum flavor and food additive, with a dominant caramel odor that adds notes of maple syrup, raw sugar, or a caramelized taste with nutty nuances to a preparation.

It is commonly found in pastries, ice cream, beverages, cosmetics and tobacco. It is also used to flavor coffee or chocolate.

How to evaluate ecigarette e liquid ?

  Dr. Vardavas' previous study noted the presence of 246 different flavors and additives in the 122 e liquid samples.

But Dr. Farsalinos notes that without specifying on their concentration, it is impossible to evaluate them correctly.

In the end, he emphasizes that simply using the regulatory framework on product safety does not allow to affirm that the electronic cigarette is or is not harmful, that it must be evaluated within a framework specific to its actual use.

The research must especially study the production of vapor and the possible thermal degradation of the products during their vaporization and not test products in liquid form.

Conclusions of this study on flavors

  " In conclusion, a risk assessment analysis based on the EUCLP regulatory framework identified that only one of the reported flavouring chemicals found in e-cigarette liquids was present at levels sufficiently high to classify it as toxic based on the EU regulatory framework.

For the rest, the concentrations reported were by far lower than those needed to classify them as toxic.

Even if a liquid contained all the chemical compounds at the maximum reported concentration, still any toxicity classification would be associated with the use of only one compound at the maximum concentration.

It is important for a proper regulatory framework to continuously monitor the composition and quality of e-cigarette products available in the market and ensure that appropriate standards are used.

Such toxicological surveillance of e-cigarette liquids can be valuable in identifying, removing or adequately diluting potentially harmful compounds as part of standard regulatory practice.

The relative simplicity of the chemistry of e-liquids and e-cigarette aerosols makes this method practically feasible, whereas it is totally implausible for combustible tobacco products. "

Ressources :

- Toxicity classification of e-cigarette flavouring compounds based on European Union regulation: analysis of findings from a recent study

- Dr Vardavas study

Read more :

Are e cigarette flavors dangerous ?

Diacetyl in vape juice ?

Propylene glycol, compound of e liquid

All about nicotine

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© Arom-Team 2019