A new study released today by the New England Journal of Medicine reports finding high levels of formaldehyde in the aerosol of electronic cigarettes, leading the authors to conclude that the cancer risk associated with vaping is higher than that associated with smoking.
(See: Jensen RP, Luo W, Pankow JF, Strongin RM, Peyton DH. Hidden formaldehyde in e-cigarette aerosols. New England Journal of Medicine 372;4, January 22, 2015.)
The study examined the aerosol produced by a tank system electronic cigarette. The aerosol was collected and analyzed for formaldehyde. Two voltage settings were used: low (3.3V) and high (5.0V).
The main finding was that at low voltage, no formaldehyde was detected, but at high voltage, high levels of formaldehyde were detected. Using these levels, the authors extrapolate to derive an overall lifetime cancer risk from vaping, which they claim is higher than that from cigarette smoking.
The Rest of the Story
There's just one problem with the study, but this problem renders its conclusion invalid.
The conditions used to study the e-cigarette aerosol at the high voltage setting were unrealistic and under such conditions, a vaper would never be able to use the product. This is because the wattage being used was so high that the vaporizer was overheated (for a conventional e-cigarette it would likely damage or burn the coils), creating a horrible taste which a vaper could not tolerate. This is sometimes referred to as the "dry puff phenomenon."
Based on calculations by Dr. Konstantinos Farsalinos from data provided in the article, the resistance was no higher than 1.7 ohms. At a voltage of 5.0V, the wattage would be 14.7W. That is in the "red zone" where the vaporizer is being overheated and where, for a conventional e-cigarette, the coils would likely be damaged or burned.
Essentially, what this study demonstrates is that if you overheat a vaping system, it will produce high levels of formaldehyde. However, such conditions are not realistic, as they could not be tolerated by an actual vaper. Therefore, extrapolating from this study to a lifetime of vaping is meaningless.
On the other hand, the study does demonstrate a very important point. It is entirely feasible to produce an electronic cigarette or vaping system that does not deliver any measurable amount of formaldehyde. At the low voltage setting, no formaldehyde was detected. Rather than scaring people about the dangers of vaping and alarming them to the "fact" that vaping raises their cancer risk above that of smoking, we should instead be regulating the voltage and temperature conditions of electronic cigarettes so that the problem of formaldehyde contamination is completely avoided.
As I have argued before, instead of wasting its time and resources setting up a bureaucratic nightmare, where thousands of different products must submit pre-marketing applications, the FDA should simply promulgate basic safety standards. And one of those standards should set maximum voltage and temperature conditions for these products. That would minimize the health risks while maximizing the benefits.
ADDENDUM: Dr. Farsalinos has corrected me and pointed out that it is really the coil temperature, not the voltage, which needs to be controlled and regulated.