Electronic cigarettes do n't contain tar , other chemicals ; only liquid nicotine . Comment: FDA says safety not proved , has been refusing importations . WHO called for more safety testing in 2008 .
Electronic cigarettes do n't contain tar , other chemicals ; only liquid nicotine . CEO `` pretty sure '' e-cigarettes are safe . FDA says safety not proved , has been refusing importations . WHO called for more safety testing in 2008 .