Are E-cig Safe ？

E-cigarettes aren't thought of as 100% safe, but most experts think they're less dangerous than cigarettes, says Neal Benowitz, MD, a nicotine researcher at the University of California at San Francisco. Cigarette smoking kills almost half a million people a year in the United States. Most of the harm comes from the thousands of chemicals that are burned and inhaled in the smoke, he explains.

E-cigs don't burn, so people aren't as exposed to those toxins. A 2015 expert review from Public Health England estimated e-cigs are 95% less harmful than the real thing.

That figure is controversial and might be a little high, says Kenneth Warner, a tobacco policy researcher at the University of Michigan. But, he adds, "The worst critics of e-cigarettes would probably argue they're a half to two-thirds less dangerous. But from a practical view, they're probably on the order of 80% to 85% less dangerous, at least."