Known carcinogens, irritants found in electronic cigarettes
The FDA recently announced plans to regulate electronic cigarettes and the AMA has called for stricter regulations, but little research has been conducted that identifies the compounds released when the flavored, nicotine-infused fluid is ignited and turned to vapor.
A new study from Roswell Park Cancer Institute has analyzed vapors created by some fluids at different temperatures and found formaldehyde among other carbonyl compounds.
Maciej L. Goniewicz
“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,” one of the researchers, Maciej L. Goniewicz, PharmD, PhD, said in a press release. “Users of high-voltage e-cigarettes need to be warned about this increased risk of harmful effects.”
According to the study, most e-cigarette fluids are composed of glycerin or propylene glycol into which nicotine and flavorings are dissolved. Goniewicz and colleagues analyzed the vapors from 10 commercially available nicotine fluids and three control solutions composed of pure glycerin, pure propylene glycol or a mixture of the two solvents. The vapors were created using an e-cigarette with a variable battery voltage output of 3.2 volts to 4.8 volts.
The researchers found the amounts of formaldehyde, acetaldehyde, and acetone increased four- to 200-fold with increased temperatures associated with higher voltage. Formaldehyde is classified by the IARC as a group 1 carcinogen and acetaldehyde is classified a group 2B possible carcinogen. Acetone is a mucous membrane irritant, according to the report. Other compounds present were propanol, acetone and butanal. While previous studies showed acrolein in samples, none was found in the present study. Goniewicz attributed this to one study using 150 puffs, while his study used only 15.
When compared with the flavor-free control solvents, similar amounts of the chemicals were found, suggesting the solvents are their primary source. Further, the amount of the chemicals increased significantly with increased temperature, as did the amount of fluid consumed.
An exception was found with one fluid that was composed of polyethylene glycol in which no toxic carbonyls were found. Researchers said additional research of this fluid base is needed, and that their study was limited because it examined only two toxicity factors, nicotine solvent and battery output voltage.
Disclosure: Goniewicz reports that in 2011 he received research funds from a pharmaceutical company that manufactures smoking-cessation medications; another researcher disclosed that he received research funds from a manufacturer of e-cigarettes. Both awards apply to projects that fall outside the scope of this newly published research.