There are 3-4 substances that make up E-liquid.
These substances include:
What is PG and VG liquids?
PG (Propylene Glycol) and VG (Vegetable Glyerine, or Glycerol) are ingredients in e-liquid which create the vapor. PG is associated with a stronger “throat hit” but with less visible vapor, whereas VG has a sweetish taste and produces a much more visible vapor. Some vapers find PG irritates their throat and lungs and choose to use VG based e-liquids instead. Some e-liquids contain a blend of both ingredients to balance out the characteristics of each.
VG, PG, Flavorant and Nicotine are widely used in a variety of products for human consumption whether you vape or not considering how often you can find them in products you use daily.