Determination of Thermal Decomposition Products Generated from E-Cigarettes

Area of Science:

• Analytical Chemistry
• Environmental Science
• Toxicology

Background:

• Electronic cigarettes (e-cigarettes) heat e-liquids, typically containing propylene glycol (PG) and glycerol (GLY), to produce aerosol for inhalation.
• Understanding the thermal decomposition products of e-liquids is crucial for assessing e-cigarette safety.

Purpose of the Study:

• To identify and quantify thermal decomposition products generated from e-liquids at various electric power levels.
• To compare the chemical composition of e-cigarette aerosol with traditional cigarettes.

Main Methods:

• Analysis of thermal decomposition products from three e-cigarette brands using neat PG, neat GLY, and commercially available e-liquids.
• Varying electric power levels from 1 W to 85 W to observe product generation.
• Gas and particulate phase analysis of chemical compounds.

Main Results:

• Specific decomposition products like propylene oxide (from PG) and glycidol (from GLY) were identified.
• Formaldehyde, methyl glyoxal, glyoxal, and acrolein were detected, with concentrations increasing exponentially above 40 W.
• Thermal decomposition product concentrations were generally higher than those in traditional cigarettes, with formaldehyde reaching significant levels (4400 μg/15 puffs at 50 W in one brand).

Conclusions:

• E-cigarette use generates hazardous thermal decomposition products, even within recommended power limits.
• The generation of these harmful substances increases significantly with higher electric power settings.
• E-cigarette users should be aware of the potential health risks associated with these generated chemicals.