E- cigarettes are designed to generate a nicotine aerosol, or vapor, without the combustion of tobacco. When the user takes a draw on the device, a nicotine solution is heated and the vapor inhaled. Researchers recently measured e-cigarette vapors while using a smoking machine in controlled exposure conditions to compare secondhand smoke exposure by e-cigarette vapors VS tobacco smoke. They found that the e-cigarettes emitted significant amounts of nicotine – only without producing substantial amounts of carbon monoxide or other toxic compounds. Emissions of nicotine from e-cigarettes were 10 times lower than those of conventional tobacco cigarettes. What they did not measure was the levels of formaldehyde, acetaldehyde and acrolein that e-cigs emit.