In January 2015, R. Paul Jensen and colleagues created global headlines with a defective e-cigarette experiment.  They claimed in the New England Journal of Medicine that vapor contains “hidden” formaldehyde at far higher levels than in cigarettes.  Their measurements required overheating or “dry-puffing” e-cigarette liquid, a process that produces such harsh (not hidden) oral sensations that the vapor is intolerable to normal consumers.

As Churchill said, “A lie gets halfway around the world before the truth has a chance to get its pants on.”  The Jensen mischaracterization caused considerable damage, as it encouraged smokers to believe that vaping is more dangerous than smoking.

Last week, the formaldehyde fallacy was laid bare.  Dr. Konstantinos Farsalinos and colleagues reproduced the Jensen experiment and found that: “The high levels of formaldehyde emissions that were reported in [the Jensen] study were caused by unrealistic use conditions that create the unpleasant taste of dry puffs to e-cigarette users and are thus avoided.” Their work appears in Food and Chemical Toxicology.

Farsalinos’ group painstakingly reproduced the earlier experiment, using the same now-outdated vaping equipment that was prone to dry puffs. First, they had experienced vapers identify at what settings the “burning” taste of a dry puff was detected: 4.2 volts, 8.0 watts.  They then used Jensen’s methods to measure formaldehyde at various voltage-power settings, seen in the chart below, adapted from their publication.

Farsalinos FoodChemTox Figure 090617

Vapers detected dry puffs when the formaldehyde level was 100 micrograms (per 10 puffs).  Given that a microgram is one-millionth of a gram, Jensen’s formaldehyde level wasn’t hidden at all; at 380 micrograms, it was much higher than vapers could tolerate. At lower, normal vaping power, formaldehyde was only 20 micrograms, or two-thirds that of cigarettes.

Farsalinos cautions the scientific community: “blindly testing e-cigarettes in the laboratory setting without evaluating realistic use is a serious omission that can result in misleading conclusions about the risk to consumers compared to smoking” and such conclusions can wrongly imply “that there is little to be gained by switching to e-cigarettes.”

In response to the Jensen article in 2015, Clive Bates and Konstantinos Farsalinos published a letter in Addiction calling for its retraction; the demand was ignored.  The current publication is a much-needed antidote to Jensen’s seriously flawed and misleading findings.


Image by Ostancov Vladislav

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