The mixture used in vapor products such as e-cigarettes is called e-liquid. E-liquid formulations vary widely. A typical e-liquid is composed of propylene glycol and glycerin (95%) and a combination of flavorings, nicotine, and other additives (5%). The flavorings may be natural, artificial, or organic. Over 80 harmful chemicals such as formaldehyde and metallic nanoparticles have been found in e-liquids at trace quantities. There are many e-liquid manufacturers, and more than 15,000 flavors.
