E-liquid, e-juice or liquid nicotine refers to a substance that can be heated and vaporized ready for inhalation. The e-juice ingredients generally consist of propylene glycol (Pg), polyethylene glycol 400 (P400), glycerine (G) and nicotine, varying amounts of alcohol can also added to the e-liquid solution. The alcohol is added as a thinning agent and helps with vaporization.
Flavouring liquid nicotine
As well as the basic ingredients above, a diverse range of flavourings can be used to enhance the taste of vaping. However, some of the chemicals used as flavouring additives have been linked to illness. The butterscotch VIP liquid had to be recalled and destroyed following findings that it was linked to lung disease. Some online retailers are boasting over 300 different e-juice flavours. Trials are under way to see what happens when these additives are heated and vaped.
The amount of nicotine in e-juice is variable, ranging from no nicotine at all up to 36mg. Unregulated production of liquid nicotine is causing fluctuations in the nicotine content of e-liquid, this leaves consumers unaware of the exact quantity of nicotine in the products. Not all the vaporized nicotine is absorbed by the body.
Absorbing vaporized nicotine
When the e-liquid is heated to around 60c by the lithium-ion battery, the active ingredients (PG), (P400), (G) and Nicotine are vaporized and they produce a mist that looks like cigarette smoke but with none of the harmful compounds associated with tobacco. On inhalation, the nicotine is absorbed into to the body through the walls of the lungs.
Not all the nicotine is absorbed by the body; the amount of nicotine that gets into the bloodstream when vaping varies. Research found that between 5% to 40% of the nicotine content is absorbed through the cell walls, the remainder is exhaled. The amount of nicotine ingested differs from person to person, dependant on age, health of lungs and the circulatory system.
These findings indicate a higher absorption rate than that of smoking tobacco. It is estimated that between 1% and 15% of nicotine from a cigarette is taken in by the body when smoked.
The higher nicotine absorption rate linked to vaporizing is caused by the chemical make-up of the vapour and vaping process itself. E-liquid enters the throat at a cooler temperature than that of tobacco smoke, it leaves a fine vapour coating all the way through the lungs right down to the Alveoli. This allows more nicotine to enter the blood and stimulate the user.