most e-cigarettes only contain water and flavoring. Based Vaping Explained Pediatric Environmental Health Center |

Nicotine is one of the most harmful, as it is highly addictive and alters brain chemistry

"This continued inaction is a shocking deference to the tobacco industry, which has repeatedly demonstrated its willingness to profit from products that result in death," said Karen Knudsen, the CEO of the American Cancer Society and its affiliate Cancer Action Network

It's the rechargeable powerhouse that provides the energy to heat up the e-liquid

The familiar laundry list of nasties associated with cigarette smoke (formaldehyde, acetone, arsenic, cadmium, lead, hydrogen cyanide, tar) are mostly combustion byproducts that form once the additive-laced tobacco and paper start burning, not ingredients sprinkled in for flavor