Format

Send to

Choose Destination
Tob Control. 2019 Feb 11. pii: tobaccocontrol-2018-054616. doi: 10.1136/tobaccocontrol-2018-054616. [Epub ahead of print]

Characteristics and toxicant emissions of JUUL electronic cigarettes.

Author information

1
Department of Mechanical Engineering, American University of Beirut, Beirut, Lebanon.
2
Chemistry, American University of Beirut, Faculty of Arts and Sciences, Beirut, Lebanon.

Abstract

INTRODUCTION:

JUUL is an electronic cigarette (ECIG) with a compact form factor. It is prefilled with a liquid that is advertised to contain a high concentration of nicotine salt. JUUL commands 50% of the US ECIG market share, and its wide popularity with underage users has triggered unprecedented actions by the US FDA. Apart from its nicotine salt-containing liquid and compact form, a salient advertised design feature is a control circuit that limits the heating coil temperature, presumably reducing unwanted toxicants. In this study, several tobacco-flavoured JUUL devices were reverse engineered, and their aerosol emissions were studied.

METHODS:

Total nicotine and its partitioning (freebase and protonated), propylene glycol/vegetable glycerin (PG/VG) ratio, and carbonyls were quantified by gas chromatography (GC) and high performance liquid chromatography (HPLC). The temperature control functionality of JUUL was investigated using a temperature-controlled bath in which the coil was submerged.

RESULTS:

The liquid nicotine concentration was found to be 69 mg/mL, and the liquid and aerosol PG/VG ratio was found to be 30/70. In 15 puffs, JUUL emitted 2.05 (0.08) mg of nicotine, overwhelmingly in the protonated form. Carbonyl yields were significantly lower than those reported for combustible cigarettes, but similar to other closed-system ECIG devices. The heating coil resistance was 1.6 (0.66) Ohm, while the maximum power delivered by the JUUL device was 8.1 W. The control circuit limited the peak operating temperature to approximately 215C.

CONCLUSIONS:

JUUL emits a high-nicotine concentration aerosol predominantly in the protonated form. JUUL's nicotine-normalised formaldehyde and total aldehyde yields are lower than other previously studied ECIGs and combustible cigarettes.

KEYWORDS:

carcinogens; electronic nicotine delivery devices; nicotine

Conflict of interest statement

Competing interests: AS is a paid consultant in litigation against the tobacco industry and is named on a patent application for a device that measures the puffing behaviour of electronic cigarette users.

Supplemental Content

Loading ...
Support Center