A study published in Indoor Air from the Fraunhofer Wilhelm-Klauditz-Institut in Germany examined secondhand emissions from several e-cigarettes in a human exposure chamber. Each e-cigarette was puffed 6 times and data were collected for a conventional cigarette, also puffed 6 times.

While the e-cigarette produced lower levels of toxins in the air for nonsmokers to breathe than the conventional cigarette, there were still elevated levels of acetic acid, acetone, isoprene, formaldehyde and acetaldehyde, averaging around 20% of what the conventional cigarette put into the air.

Thus, while not as polluting as a conventional cigarette, the e-cigarettes are putting detectable levels of several significant carcinogens and toxins in the air.

No one should have to breathe these chemicals, whether they come out of a conventional or e-cigarette. No one should smoke e-cigarettes indoors that are free of other forms of tobacco smoke pollution.