Effects of freebase/protonated nicotine concentration, liquid composition and electrical power on throat hit in direct-to-lung vaping: theory and clinical measurements.

Background: For decades, the tobacco industry has engineered the sensory characteristics of combustible tobacco products including the degree of harshness experienced at the back of the throat. Commonly referred to as 'throat hit', this harshness derives from absorption of gas phase nicotine and other constituents by the sensory nerves. People who use tobacco products associate throat hit with the positive psychological effects of nicotine, making it a secondary reinforcer for smoking.