Electronic cigarettes are ostensibly safer for you than conventional cigs (you're not inhaling tar and other elements of tobacco smoke), but it now looks like they might not be much better at all. Researchers have found that 75 percent of flavored e-cigs contain diacetyl, a flavoring chemical that can produce "popcorn lung" disease when inhaled over the long term. To boot, many of the tested flavors had other related chemicals (like 2,3-pentanedione and acetoin) on top of known risky ingredients, such as formaldehyde.