Current Knowledge

• Electronic cigarettes are a rapidly growing business with annual sales doubling yearly to $1 billion in 2013. • Little scientific evidence exists on secondhand exposures to the aerosols and vapors exhaled by the user of an electronic cigarette. • A non-user may be exposed to aerosol particles smaller than 1000 nanometers, similar in size to tobacco smoke and diesel engine smoke. The exact size distribution depends on the chemical composition of the electronic cigarette liquid, the e-cigarette device operation, and user vaping preferences. • The aerosol and gases produced by e-cigarettes contain nicotine, glycerin/glycols, artificial flavorings, and preservatives