Public meetings offer an open tribune to scientists

Conference room at GFN event in Warsaw
Conference room at GFN event in Warsaw

The Global Forum on Nicotine, held in Warsaw last June 2016, was the opportunity for stakeholders to meet and discuss on diverse subjects and especially about e-cigarettes. It was also the occasion for recognized scientific figures to present their last results about vaping, and the occasion for Big Tobacco companies to promote the most recent outcomes of their R&D department.

It has fed controversies to see Big Tobacco companies immersed among vaping advocates to defend their harm reduction solutions. A lot of controversies also because in such meetings, what is presented is not screened by the peer-review process that, in an ideal word, should prevent junk science from spreading in scientific journals. Hence, the message that is conveyed by most publication does not receive the agreement of peers and the accuracy of the findings only depends on the honesty of their authors.

Can we trust in anything presented during conferences?

And this is, in fact, the core of the issue: can we trust in what is delivered during public meetings?

The answer is probably, in general. But, as all scientific communication, they require to be taken with caution and replaced into the context, especially when marketing interests are in play.

In this poster, British American Tobacco (BAT) researchers made a comparison between the vapour from a Vype and a reference cigarette [1]. The reference cigarette 3R4F (Philip Morris), has been developed to replace the depleting supply of the former reference, 2R4F (Philip Morris) and is the new reference for quantitative relative emissions by e-cigarettes.

The authors put forward substantial reductions in the e-cigarette emissions for all toxicants, including the now popular acrolein, diacetyl or formaldehyde. Most cigarette smoke toxicants could not be detected in the e-cigarette vapor and their level in vapor is comparable to the blank experiment consisting in filtered ambient air.

From McAdam et al, 2016
From McAdam et al, 2016

According to BAT, this data is the most comprehensive comparison to date between smoke and e-cigarette emissions in which Vype was found to have on average 92-99% less toxicant levels than in conventional cigarette smoke.

In a press release, Head of Research for Next Generation Products at British American Tobacco, Dr Kevin McAdam, declares that “There are few publications examining the broad chemical composition of e-cigarettes, with most focusing on specific compounds or compound groups” and concludes that Vype reduces toxicity by 99% for WHO and FDA truncated lists, and over 92% for the full FDA HPHC list.

“We have tested for a total of 142 compounds, including those listed by the US Food and Drug Administration (FDA) as harmful or potentially harmful (HPHC), those compounds listed by the World Health Organisation (WHO), and Health Canada, and those reported previously to be generated by e-cigarettes.”Dr Kevin McAdam - BAT

Such results are not so surprising

Nevertheless, when compared to the reference cigarette, three aerosol constituents were measured at higher levels:

  • propylene glycol (PG),
  • vegetable glycerine (VG) and
  • menthol,
  • Chromium (Cr)

The researchers explain that such results are not surprising since PG and VG are genuine constituents of the e-liquid and menthol used as a flavor. With a resistive wire (coil) made of Nichrome, an alloy of Nickel (Ni) and Cr, it is also not surprising to see Cr released into the aerosol, underlines the researcher.

In a peer-reviewed published version of BAT’s GFN16 scientific communication [2], Cr was high, on average, over the one hundred first puffs and not quantifiable (NQ) in the following ones, which evokes the volatilisation of this metal from its source.


A resistive wire heated red is a potential source of metals for the aerosol.
A resistive wire heated red is a potential source of metals for the aerosol.

Since the alloy is Nichrome, one could expect having also Ni in the aerosol, released by volatilisation of this metal from the resistive wire. And its presence is even expected at high level since Nichrome is made of 80% Ni and 20% Cr. So, if Cr was found, why not Ni?

In the poster, the presence of Ni was not documented. In the research paper [2], Ni was found “not quantifiable” (NQ) in the aerosol, because under the quantification limit, and also “not quantifiable” in the reference cigarette smoke for the same reason. The authors do not discard its presence in the e-cigarette but they believe it to be at very low level. Ni was however found three times as large as Cr in the reference cigarette smoke [3] although BAT researchers couldn’t quantify it during their analyses. Is the analytical performance questionable?

Does it mean that other important constituent slipped under their radar because of analytical constraints?

BAT is the second, after Lorillard (Reynolds), to claim that e-cigarette aerosols are innocuous during public e-cigarette meetings. The strategic merging between the two companies is probably not a coincidence. Other Big Tobacco compagnies like Fontem Ventures (Imperial Brands, ex-Imperial Tobacco) and, more recently, Altria also proved proficiency to quantify e-cigarette emissions.

The case of Ni is intriguing and deserves interest since it is one of the numerous constituents that are screened by the European TPD. In the USA, for instance, there is no such requirement despite a more constraining regulatory process.

Caution is the key word

Caution is the key word when other laboratories detect high levels of harmful compounds on similar products. Who’s right, who’s wrong? The truth is probably in between but the fact is that, compared to smoking, the e-cigarette is surely a safer option for smokers and is promoted as such on the short term by the Royal College of Physicians, London. By the way, the “95% safer” claimed by Public Health England falls in the 92-99% interval of safety that this study finds compared to combusted tobacco.

For further readings on metals released in vapor:

A chemist’s advice: Don’t Dry-Burn your coil

[1] McAdam K., Margham J., Foster M., Wright C., Mariner D., Proctor C. 2016. Chemical composition of an e-cigarette aerosol – a quantitative comparison with cigarette smoke. Available at Accessed 19th September 2016.

[2] Margham J., McAdam K., Foster M., Liu C., Wright C., Mariner D., Proctor C. 2016. Chemical composition of an e-cigarette aerosol: A quantitative comparison with cigarette smoke. Chem. Res. Toxicol. DOI: 10.1021/acs.chemrestox.6b00188. Publication Date (Web): September 18, 2016

[3] Purkis, S., & Intorp, M. (2014). Analysis of reference cigarette smoke yield data from 21 laboratories for 28 selected analytes as a guide to selection of new CORESTA Recommended Methods. Beiträge zur Tabakforschung/Contributions to Tobacco Research, 26(2), 57-73.

  • Falken Vape

    Do you know for sure that the Cr found is from the coil decomposition and is hexavalent? I don’t say it’s not, but never seen clear evidence/measurement of that (and there are other sources of chromium in atomizers).