Aldehyde levels in e-cigarette aerosol: Findings from a replication study and from use of a new-generation device

Purpose: A recent study identified high aldehyde emissions from e-cigarettes (ECs), that when converted to reasonable daily human EC liquid consumption, 5 g/day, gave formaldehyde exposure equivalent to 604-3257 tobacco cigarettes. We replicated this study and also tested a new-generation atomizer under verified realistic (no dry puff) conditions. Design: CE4v2 atomizers were tested at 3.8 V and 4.8 V, and a Nautilus Mini atomizer was tested at 9.0 W and 13.5 W. All measurements were performed in a laboratory ISO-accredited for EC aerosol collection and aldehyde measurements. Results: CE4v2 generated dry puffs at both voltage settings. Formaldehyde levels were > 10-fold lower, acetaldehyde 6-9-fold lower and acrolein 16-26-fold lower than reported in the previous study. Nautilus Mini did not generate dry puffs, and minimal aldehydes were emitted despite > 100% higher aerosol production per puff compared to CE4v2 (formaldehyde: 16.7 and 16.5 mu g/g; acetaldehyde: 9.6 and 10.3 mu g/g; acrolein: 8.6 and 11.7 mu g/g at 9.0 W and 13.5 W, respectively). EC liquid consumption of 5 g/day reduces aldehyde exposure by 94.4-99.8% compared to smoking 20 tobacco cigarettes. Conclusion: Checking for dry puffs is essential for EC emission testing. Under realistic conditions, new-generation ECs emit minimal aldehydes/g liquid at both low and high power. Validated methods should be used when analyzing EC aerosol.