An E-Liquid is a mixture of a couple of ingredients. VG which is vegetable glycerine, is also used in the food industry as a flavour enhancer and thickener. PG stands for propylene glycol and is also used in the food industry. PG is used as a flavouring and to maintain moisture in foods. Both of the main ingredients in vape liquid are known to be very safe and not harmful to human, hence their everyday use in food! The other ingredients would include nicotine, if you have any, and the flavourings for the flavour. That's it!