“Carbonyl Compounds in Electronic Cigarette Vapors: Effects of Nicotine Solvent and Battery Output Voltage”
Since this faulty study was obviously the inspiration for latest scaremongering bit, all this also applies to:
“Hidden Formaldehyde in E-Cigarette Aerosols”
The problems with the original study seem to be based on honest mistakes. But this piece gives the impression of deliberate scaremongering propaganda.
This is a perfect example of how to ruin the value of scientific data by using erroneous assumptions to reach useless conclusions. Let’s start with:
Variable voltage EC allows user to change the voltage of the device to increase […] nicotine delivery.
Here the authors simply assume a typical usage for VV batteries. That is even more obvious in the NYT article: http://www.nytimes.com/2014/05/04/business/some-e-cigarettes-deliver-a-puff-of-carcinogens.html?hpw&rref=business&_r=1
Dr. Goniewicz, an assistant professor of oncology at the Roswell Park Cancer Institute in Buffalo, said people using the systems “want more nicotine, but the problem is they’re also getting more toxicants.”
As any experienced vaper could have told this probably brilliant, but sadly ignorant man: If you want more nicotine, you simply use stronger liquids! Or vape more often.
The VV is used exclusively to find the “sweet spot”. To get the optimal vaping experience from that specific atomizer and liquid. And—for me—that is primarily the taste. Followed by the sensation qualities of the vapor itself.
And there is more: Increasing the power past the level the atomizer is designed for won’t increase the amount of vapor and nicotine. The possible liquid flow is the limiting factor. It is a dynamic system. As long as enough liquid keeps reaching the coil, all the power is consumed by the evaporation process. When the temperature rises because of the excessive power, the amount of delivered nicotine is even lower, as nicotine is destroyed (oxidized) by higher temperatures.
There is also a huge variety of e-liquids on the market, which are manufactured and distributed by various companies. The aim of the study was to evaluate the extent to which nicotine solvent and battery output voltage affect the levels of carbonyls in the vapors of these second generation products.
And here is the next fatal assumption: All second generation products to be basically the same. So they tested only a single type of clearomizer. As I explained in ->Don’t Dismiss Differences there are huge differences in the designs and operating characteristics of advanced systems. Especially the atomizers.
Even worse: It’s one that usually is sold in a set with a “battery with voltage of 3.4V, and a battery voltage stabilization system.” So we can safely assume that this clearo was designed to have its best performance at about 3.4V. Operating it at 4V would already be pushing its limit. More would be totally useless. Even an inexperienced vaper would automatically reduce the voltage to avoid the excruciating taste of a “dry hit”.
It’s like evaluating a toaster. Assuming that people use the highest setting to get it especially crispy. Measuring the acrolein generated at the different settings. And then projecting alarm that burning the toast at the highest setting generated huge amounts. While true, it totally misses the point that it’s also completely inedible. Now drawing the conclusion that these settings schould be severely limited to protect the users from ingesting carbonized white bread misses the whole point of higher settings: They are used for other kinds of bread! There also is no need to protect people. If the smell and sight isn’t enough, one bite and such a piece of charcoal is trashed.
Next big problem: The puffing regime.
puff duration 1.8 s, […] pressed the button manually 1 s before each puff was taken
That is completely unrealistic. First of all, I don’t know any vaper who fires a whole second before puffing. Most begin to draw slowly at the same time as pressing the button. Then the duration: Vapers usually draw slower but longer than a smoker. It’s the first thing you have to adjust to when switching. Vaping is a physically much more complex dynamic process than smoking. One of the major factors and differences is the air stream:
- Smoking: Rather linear correlation–drawing harder increases the conbustion and the amount of smoke and its temperature.
- Vaping: More reciprocal.
– Drawing too slow (worst case: not at all) will not remove the vapor fast enough. The vapor and the coil will get too hot. Depending on the atomizer design it may also hamper the liquid flow which may depend on lowered pressure.
– Drawing much harder will get the vapor diluted with too much air. And cool the coil too much, so that less vapor is produced. It also may draw too much liquid to the coil so that it is “drowned” and even less vapor is produced.
So–very unlike smoking–you can’t just simply select an arbitrary puffing regime and expect it to represent an applicable model of real vaping. The individual optimum strength of the air stream depends on:
- Power applied (not just voltage!)
- Coil & airpath design
- Liquid flow (design, wicking, liquid viscosity)
As a smoker I used to draw it directly into the lung (1-2 s). Now as a vaper I usually draw one or two mouthfuls of vaper and expell directly through the nose without inhaling (to savor the flavor) and inhale the last mouthful (5-8 s).
So the applied puffing regime probably renders the collected data inapplicable for reallife situations and almost useless.
Get some help from experienced vapers.
- To tell you, when the “toast” is burned inedibly.
- To set up realistic puffing regimes that model reality for applicable data.
- Use Public Preview
Other Public Reviews:
Dr. Farsalinos http://www.ecigarette-research.com/web/index.php/2013-04-07-09-50-07/2014/162-nyt-formald (“Formaldehyde release in e-cigarette vapor / The New York Times story explained in detail”)
Please leave links to other reviews.
Some links to reactions on the latest scaremongering wave about formaldehyde swamping the media:
Scaremongering reloaded. A few comments and analyses of the current formaldehype craze:
Debunked by Dr. Farsalinos: http://www.ecigarette-research.com/web/index.php/2013-04-07-09-50-07/2015/191-form-nejm
Follow up: http://www.ecigarette-research.com/web/index.php/2013-04-07-09-50-07/2015/192-form-ver
Professor Peter Hajek: http://www.sciencemediacentre.co.nz/2015/01/22/formaldehyde-in-e-cigarettes-expert-responds/
Dr. Michael Siegel: http://tobaccoanalysis.blogspot.de/2015/01/new-study-reports-high-levels-of.html
Professor Jacques Le Houezec (french): http://jlhamzer.over-blog.com/2015/01/desinformation-la-difference-entre-une-etude-en-laboratoire-et-la-realite.html
Fergus Mason. http://fergusmason.com/?p=354
American Vaping Association: http://vaping.info/news/2015/new-e-cig-study-hypes-formaldehyde-fears-based-faulty-experiments
Collections of these links and more on the topic:
Dr. Farsalinos: E-cigarettes generate high levels of aldehydes only in “dry puff” conditions (irrespective of the power levels)
En français: Les émissions d’aldéhydes sont bien dues au phénomène de surchauffe