Table 1.

Comparison of toxin levels between conventional and electronic cigarettes

Toxins	Conventional cigarette (mcg in smoke)	Electronic cigarette (mcg per 15 puffs)	Average ratio (conventional vs. electronic cigarette)
Formaldehyde	1.6–52	0.20–5.61	9
Acetaldehyde	52–140	0.11–1.36	450
Acrolein	2.4–62	0.07–4.19	15
Toluene	8.3–70	0.02–0.63	120
NNN	0.005–0.19	0.00008–0.00043	380
NNK	0.012–0.11	0.00011–0.00283	40

Source: Goniewicz ML, et al. Tobacco Control 2014; 23(2): 133–139.

NNN and NNK are the tobacco-specific nitrosamines, nicotine-derived nitrosamino ketone and N′-nitrosonornicotine, respectively. Comparison of toxin levels between conventional and electronic cigarettes was made using a standardized approach to puff time and puff inhalation.