Having a diverse product range is an important part of any consumer business. E‑cigarette companies are no different.

E-cigs have an impressive array of different flavours, types of vaping device, nicotine strengths and varying propylene glycol (PG) and vegetable glycerin (VG) ratios. Each product and type of e-liquid is aimed toward a different consumer group, maximising interest and customers amongst the vaping community.

The fruity side of e-cigs

We can marvel at the creativity of e-liquid producers – although the recently implemented TPD regulations have certainly impacted on their product offerings. They are letting the creative juices flow… E-liquid products seem to have names resembling fruits, desserts and more exotic foods and flavours. You may be slightly disappointed to find that there is no ‘essence of Victoria sponge’ in the ingredients list. Rather, the formulations are usually a fairly short list of chemical compounds, typically present at less than 1% of the e-liquid.

If it’s food-based, is it safer?

Bibra has worked with many e-cigarette manufacturers in recent years. We have found that many of these chemical ingredients are shared across several e-liquid formulations, so it made sense for Bibra to evaluate each ingredient, rather than each e-liquid product. See our toxicity and addictiveness monographs for more information.

These ingredients clearly exhibit characteristic flavours and fragrances. Indeed, many of them are EU- or US FDA-approved food additives, or even cosmetic ingredients.

Does this, therefore, make them safe for vaping?

It is crucially important to realise that the route of exposure of these substances has a significant impact to, not only their toxicological profiles, but their absorption and metabolism. For example, one compound may be given regulatory approval as a food additive based on very low estimated intake levels with little or no toxicological data. Does the lack of safety concern as a minor food additive translate into a “this ingredient is safe to inhale at high concentrations throughout your adult life”?

And even if there were some toxicity data on this hypothetical flavouring agent – for example a repeated dose (90-day) feeding study in rodents – just because the substance demonstrated tolerability in one oral study, does this show the ingredient is safe to vape (likely repeated inhalation for several years)?

Bibra’s expertise can help

We have learnt from working on literally hundreds of e-liquid ingredient monographs for TPD purposes, that the vast majority of these flavouring substances lack sufficient toxicological data. Almost all of them have at least one data-gap for a major toxicity endpoint. The way forward is to conduct more toxicological evaluations for these substances. More high-quality, laboratory animal repeated-dose inhalation toxicity studies would be ideal from a scientific perspective. However, there are many ethical, timing and economic issues associated with such data gathering.

So, how is it possible to demonstrate the safety of vaping e-liquid products?

One way is to conduct a consumer health risk assessment of the e-liquid formulation and/or the emissions it produces when heated. This may involve routine toxicology techniques, such as read-across and (Q)SAR, and incorporate expert-guidance for deriving tolerable levels. Bibra can help: human health risk assessment is one of our core competencies. Using our many years of experience working for a wide range of clients, we propose scientifically-supported and independent opinions on the toxicological acceptability of these products.

Get in touch, we would be pleased to discuss how we can assist further.



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