what is in e-cigarettes an e-cigarette? Vaping: How E-cigs Work (Infographic)
Description
Some people flick cigarettes away when they are done smoking them

Interestingly, the nicotine levels found in the samples from e-cigarette users were very similar to those who used NRT and to smokers

Similarly, Ingebrethsen et al

The possible shades of colored lines in the Test Regions may vary

Addiction Nicotine is the primary addictive substance in cigarettes, and it is highly addictive

[39] [40] Many e-liquids use nicotine salts made by adding organic acids such as benzoic acid to nicotine, so as to reduce throat irritation
