Carbonyl compounds in electronic cigarette vapors: effects of nicotine solvent and battery output voltage.
BACKGROUND
Glycerin (VG) and propylene glycol (PG) are the most common nicotine solvents used in e-cigarettes (ECs). It has been shown that at high temperatures both VG and PG undergo decomposition to low molecular carbonyl compounds, including the carcinogens formaldehyde and acetaldehyde. The aim of this study was to evaluate how various product characteristics, including nicotine solvent and battery output voltage, affect the levels of carbonyls in EC vapor.


METHODS
Twelve carbonyl compounds were measured in vapors from 10 commercially available nicotine solutions and from 3 control solutions composed of pure glycerin, pure propylene glycol, or a mixture of both solvents (50:50). EC battery output voltage was gradually modified from 3.2 to 4.8V. Carbonyl compounds were determined using the HPLC/DAD method.


RESULTS
Formaldehyde and acetaldehyde were found in 8 of 13 samples. The amounts of formaldehyde and acetaldehyde in vapors from lower voltage EC were on average 13- and 807-fold lower than in tobacco smoke, respectively. The highest levels of carbonyls were observed in vapors generated from PG-based solutions. Increasing voltage from 3.2 to 4.8V resulted in a 4 to more than 200 times increase in formaldehyde, acetaldehyde, and acetone levels. The levels of formaldehyde in vapors from high-voltage device were in the range of levels reported in tobacco smoke.


CONCLUSIONS
Vapors from EC contain toxic and carcinogenic carbonyl compounds. Both solvent and battery output voltage significantly affect levels of carbonyl compounds in EC vapors. High-voltage EC may expose users to high levels of carbonyl compounds.
Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health, Sosnowiec, Poland; Department of General and Inorganic Chemistry, School of Pharmacy, Medical University of Silesia, Sosnowiec, Poland;
Leon
L
Kosmider
Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health, Sosnowiec, Poland; Department of General and Inorganic Chemistry, School of Pharmacy, Medical University of Silesia, Sosnowiec, Poland;
Andrzej
A
Sobczak
Department of General and Inorganic Chemistry, School of Pharmacy, Medical University of Silesia, Sosnowiec, Poland;
Maciej
M
Fik
Department of General and Inorganic Chemistry, School of Pharmacy, Medical University of Silesia, Sosnowiec, Poland;
Jakub
J
Knysak
Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health, Sosnowiec, Poland;
Marzena
M
Zaciera
Department of Chemical Hazards and Genetic Toxicology, Institute of Occupational Medicine and Environmental Health, Sosnowiec, Poland;
Jolanta
J
Kurek
Department of Health Behavior, Roswell Park Cancer Institute, Buffalo, NY maciej.goniewicz@roswellpark.org.
Maciej Lukasz
ML
Goniewicz
D000079:Acetaldehyde / Q000009:adverse effects / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D066300:Electronic Nicotine Delivery Systems / Q000009:adverse effects* / Q000592:standards; D005557:Formaldehyde / Q000009:adverse effects / Q000032:analysis*; D006801:Humans; D009538:Nicotine / Q000009:adverse effects / Q000032:analysis*; D012997:Solvents / Q000009:adverse effects / Q000032:analysis*
D012997:Solvents; D005557:Formaldehyde; D009538:Nicotine; D000079:Acetaldehyde