High-voltage e-cigarettes may expose users to increased levels of toxic chemicals

High-voltage electronic cigarettes (e-cigarettes) may expose users to increased levels of toxic chemicals, including formaldehyde and acetaldehyde, according to research led by Maciej Goniewicz, PhD, PharmD, a researcher in the Department of Health Behavior at Roswell Park Cancer Institute (RPCI). The study was published online today by Nicotine and Tobacco Research, a peer-reviewed journal.

E-cigarettes are battery-operated devices in which heat is applied to a liquid solution (e-liquid) filled with nicotine, flavors and other chemicals. The user then inhales the resulting vapor. The e-liquid is primarily composed of glycerin (VG) and propylene glycol (PG).

Some e-cigarette devices allow the user to change the voltage of the device to increase vapor production and nicotine delivery. Dr. Goniewicz and colleagues examined various chemicals in vapors generated from the same e-cigarette but at variable voltages. They found that when an e-cigarette was operated at lower voltage, the vapors generated contain only traces of some toxic chemicals. These compounds included formaldehyde, a known carcinogen; acetaldehyde, which is considered a possible carcinogen to humans; and two chemicals known to irritate nasal, lung and/or mucous tissues, acrolein and acetone. When the voltage was increased, the levels of toxicants also significantly increased.

"These results suggest that some types of electronic cigarettes might expose their users to the same or even higher levels of carcinogenic formaldehyde than tobacco smoke," says Dr. Goniewicz. "Users of high-voltage e-cigarettes need to be warned about this increased risk of harmful effects."

The researchers examined two factors that demonstrated increased health risk to users: nicotine solvent and battery output voltage, says Dr. Goniewicz. He recommends further research to examine other product characteristics that may impact toxicity, such as the types of heating elements, flavorings, additives and product storage conditions.

"These findings will help to provide a scientific foundation for product safety and will inform the public health community as it establishes regulations of these devices," notes Andrew Hyland, PhD, Chair of the Department of Health Behavior at Roswell Park.

This study, "Carbonyl compounds in electronic cigarette vapors - effects of nicotine solvent and battery output voltage," was conducted in collaboration with scientists from the Medical University of Silesia in Poland.

Dr. Goniewicz reports that in 2011 he received research funds from a pharmaceutical company that manufactures smoking-cessation medications; another co-author disclosed that he received research funds from manufacturer of e-cigarettes. Both awards apply to projects that fall outside the scope of this newly published research.