All liquids, also known as E-liquid, consist for the most part of a mixture of Natural Glycerin (VG) and Propylene Glycol (PG). Common ratios are 50/50, 60/40, 70/30 and 80/20. These two substances are frequently used in food processing, but also in cosmetics.
In addition, E-liquids are often flavored, for example tobacco, fruit, vanilla and coffee. For E-liquids sold at Puff, only 100% food-grade flavors are used. This means that the flavors have been tested and found to be safe for human intake (the substances are tested for oral intake and degradation via the gastrointestinal tract). Finally, E-liquid can also contain nicotine, but this is often optional.