“Passive smoking” has been hotly contested. Is there a case for “passive vaping?” Hardly.

A detailed study of e-cigarette vapor by German investigators at the Fraunhofer Wilhelm-Klauditz Institute’s Department of Material Analysis and Indoor Chemistry detected virtually no quantifiable levels of 20 volatile organic compounds (VOCs) present in cigarette smoke.

They had a volunteer smoker puff three e-cigarette liquids and one combustible cigarette in a cramped test chamber measuring about six feet cubed. The volunteer took six, deep three-second puffs on each item at one-minute intervals; air samples were taken for 15 minutes after the fourth puff.

These are the results for the 20 agents with the highest concentrations:

Concentrations (ug/m3) of Volatile Organic Compounds (VOCs) in Vapor From Three E-cigarette (Average) and Smoke From a Cigarette
VOC E-cigarette Vapor Cigarette Smoke
Propylene glycol * 112
1-hydroxy-2-propanone * 62
2,3-butanedione * 21
2,5-dimethylfuran * 5
2-butanone 2 19
2-furaldehyde * 21
2-methylfurane * 19
3-ethenyl-pyridine * 24
Acetic acid 13 68
Acetone 20 64
Benzene * 22
Isoprene * 135
Limonene * 21
M,p-xylene * 18
Phenol * 15
Pyrrole * 61
Toluene * 44
Formaldehyde 12 86
Acetaldehyde 2 119
Propanal * 12

* Unquantifiable/same as empty chamber

Five VOCs were detected in e-cigarette vapor at minuscule levels. The level of formaldehyde was similar to that measured before the e-cigarette puffs, leading the investigators to comment that it “might be caused by the person in the chamber itself, because people are known to exhale formaldehyde in low amounts.” Acetone and acetaldehyde may have resulted from combustion of propylene glycol during e-cigarette puffing, which also occurs to a larger extent during smoking. Propylene glycol, a major component of vapor, was not present in the chamber during-after e-cigarette use.

Although the investigators aimed to identify VOCs “under near-to-real-use conditions to estimate the effect of ‘passive vaping,'” the use of a six foot cubed chamber is not “real world.” They answered their title question, “does e-cigarette consumption cause passive vaping?” in the affirmative, but these barely measurable results, extrapolated to rooms of normal size, confirm that bystanders have virtually nothing to worry about from vapers.

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