E-juice (or e-liquid) is the liquid heated up by vaping devices in order produce vapour that is inhaled. Most often these e-juices contain nicotine, but there are e-juices available without any nicotine. E-juices are commonly flavoured to provide a nice taste; flavourings range from simple flavours such as mint, to highly complex flavours resembling real world tastes such as milkshakes, cakes, and fruit combinations.
There are 4 basic ingredients in any given e-juice. They are:
- Vegetable Glycerine
- Propylene Glycol
An e-juice usually consist of at least 3 of these ingredients, but most often all 4 are present.
Vegetable Glycerine [Glycerol] (VG)
- VG is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic
- VG has been widely used in the food and medicinal industries
- In e-liquid VG is the component most directly responsible for producing the dense white clouds
Propylene Glycol (PG)
- PG is a viscous, colorless liquid which is nearly odorless but possesses a faintly sweet taste
- PG has also been widely used in the food and medicinal industries
- In e-liquid PG is the component most directly responsible for carrying the flavour
- Nicotine is a stimulant and alkaloid that is naturally produced by the nightshade family of plants such as tobacco. It is also found in smaller quantities in eggplant, potatoes and tomatoes
- Nicotine (separated from tobacco) is commonly used as a tool to assist with quitting cigarette/tobacco smoking
- Nicotine is generally considered to pose few health risks in this "naked" form (at lower concentrations)
- Nicotine by itself is not a known carcinogen
- There are two subtypes of nicotine used for vaping: freebase nicotine and nicotine salt
This is nicotine in its purest chemical form, making it easier to absorb when heated. This form of nicotine is less stable though, and hence harsher when inhaled.
This is commonly used in e-juices at strengths between 1mg and 18mg - historically e-juices had up to 24 or 36mg freebase nicotine, but this is increasingly rare with the adoption of nicotine salts.
This is the natural form of nicotine found in tobacco plants. It is much more stable than Freebase Nicotine (i.e. it is less harsh when inhaled) allowing higher concentrations of nicotine to be inhaled.
This is commonly used in e-juices at strengths between 10mg and 60mg. These types of high nicotine e-juices are intended for specialized devices which produce very little vapour.
Nicotine can be absorbed through the skin and e-juices containing higher than 20mg nicotine (whether salt or freebase) should be handled with extreme care. If it comes in contact with the skin it should be rinsed off immediately. In fact, nicotine higher than 20mg should generally only be purchased in a sealed pod or cartridge to avoid any contact with the skin.
- Various types of artificial and natural flavourings are used in e-juices
- These are the same flavourings that have been used in the food industry for decades
- Since the advent of vaping most of these flavourings have been tested and found safe (or modified to be safe) for inhalation
- Complex flavour combinations are often used to produce e-juices that resemble traditional food products (such as sodas, candies, cakes, etc)
- Flavouring is at the heart of what makes e-juice so special - it is one of the main reasons why many people switch to (and stick to) vaping instead of smoking tobacco cigarettes
- The ratio of vegetable glycerine to propylene glycol in an e-juice varies and is often expressed as a percentage per component present in the total volume
- Common ratios are 50/50 and 70/30 (VG/PG)
- The VG ratio of an e-juice is very rarely below 50%, which is due to the fact that PG is much harsher to inhale.
High VG (70% and up)
- These e-juices generally provide more vapour with somewhat reduced flavour intensity (this however can be countered by increasing the flavouring concentration)
- Higher VG juices are generally also considered "smoother" to inhale
- The downside to these is that VG has a high viscosity and so struggles to properly saturate the wick, which can lead to dry hits
- Extremely high VG e-juices (commonly referred to as Max VG) are generally only used with RDAs
Low VG (50% to 70%)
- These juices are commonly used with low power products intended for use with higher nicotine e-juices (such as those containing nicotine salts)
- Due to their higher concentration of PG, which is less viscous, these e-juices wick easier - preventing dry hits in smaller and less powerful vaping devices
- In colder climates, lower VG can also help keep wicks saturated