PG (Propylene Glycol) and VG (Vegetable Glycerine) are both very common products can be found in a lot of everyday items. When it comes to E-liquid, most use a blend of PG and VG together as a base that can often be over 80% of the E-liquid ingredients itself.
Both PG and VG are GRAS (Generally Recognized as Safe) ingredients, A GRAS ingredient is an ingredient that has undergone safety evaluations by experts and has been proven not to cause harm when used as intended. The most common side effects that vapers may experience are a dry mouth or sore throat, increased thirst. These symptoms can often be alleviated by drinking more water and liquids then usual to stay hydrated. In extreme cases some may find an intolerance (particularly to PG) is present.
The probability of being allergic to Propylene Glycol is quite low, although some believe those with eczema may have a >2% chance of developing allergies to Propylene Glycol. If an allergy to PG is present, it is very likely that it would already be known about as a large number of products that most use on a daily basis contain PG.
The probability of being allergic to Vegetable Glycerine is also quite low. The only people who may be affected are diabetics experiencing an issue which can convert free Glycerol to glucose. Despite this, there should not be an issue with the levels used in vaping, although a higher PG juice may be considered.
PG (Propylene Glycol) is an odorless and colorless liquid that has more viscosity than water. Some believe that PG provides a “throat hit”, but PG alone doesn’t actually have much of a throat hit. Between PG and VG, PG is a much better carrier and catalyst for the flavouring and nicotine. This means the throat irritation from nicotine and overall flavour will be greater when more PG is used in an E-liquid.
Propylene Glycol is approved by Health Canada for use in various forms in Canada. These include items injected, applied topically, and inhaled. Propylene Glycol has been around for quite some time, and can be found in a variety of products we use and consume on daily basis. This includes: ice-cream, alcoholic beverages, salad dressings, food dyes, cake mixes, pet food, sodas, asthma inhalers, toothpaste, make-up and baby wipes, perfumes and colognes, deodorant sticks, hand sanitizer and many other cosmetic products and processed foods.
Industrial-grade PG can be found in anti-freeze, paints, enamel, varnishes, airplane de-icers, and is often used as a solvent. PG was added to anti-freeze in place of ethylene glycol years ago when it was realized dogs were being poisoned from drinking puddles of anti-freeze that contained ethylene glycol. Vaping critics are quick to point out this usage of PG, but what they don't point out is the fact that these solvents use a much stronger grade than what is used in E-liquids and other commercial applications and often replaces a toxic chemical.
Most E-liquids contain some at least some PG. A lot of flavouring concentrates and nicotine bases for mixing E-liquids are suspended in PG. Most common juices contain 30-60% PG, while high and max VG E-liquids likely contain up to 20% PG.
VG (Vegetable Glycerine), much like PG, is odorless and colorless, but has a slight sweetness to it and has more viscosity than PG. VG is what produces most of the denser cloud from a vape exhale. Some believe that VG can be less harsh than PG. VG is not as good of a carrier or catalyst for flavouring and nicotine as PG. This means the throat irritation and overall flavour will be less when more VG used in an E-liquid, but more vapor will be produced.
Vegetable Glycerine is approved by Health Canada for use in various forms in Canada and is commonly used in the food, cosmetic and pharmaceutical industries. VG is often added to foods to help oil and water-based ingredients mix, sweetening, or moistening the final product. VG can be also used to help prevent ice crystals from forming in frozen desserts, such as low-fat frozen yogurt, ice cream and other desserts. VG is often added to soaps, candles, lotions, deodorants and makeup as well for its hygroscopic effect (to absorb moisture from the air).
Glycerol (a.k.a. Glycerine) is one of the most gentle organic liquids known to man. It is hypo-allergenic, non-carcinogenic, non-teratogenic and non-mutagenic. Glycerine is a common ingredient in pharmaceutical drugs, including heart medication, suppositories, cough remedies and anesthetics. Additionally, you can find Vegetable Glycerine in toothpaste, as it helps prevent toothpaste from drying out or hardening in the tube. It can also be found in aftershave products, makeup, mousse, shampoo, bubble bath, pet food, eye & ear drops, and many other dental care products beyond toothpaste.
Most E-liquids contain at least some VG. Some flavouring and nicotine bases are suspended in VG. In the early days of vaping VG wasn’t used in E-liquids. With the addition of VG, vaping has become much more enjoyable and less harsh for most. Most common juices contain 40-60% VG, but can 0-30% or as high as 90% in some cases.
PG and VG each have their own benefits and limitations. Everyone has different preferences, but a blend of around 50% PG and 50% VG is often a good starting point that will work with most devices. Here a few things to keep in mind when deciding on a PG/VG blend ratio that will work best.
PG is an excellent carrier for flavour and nicotine. When compared to VG, flavours suspended in PG tend to taste more pure. Nicotine suspended in PG tends to offer a greater throat hit when compared to nicotine suspended in VG at the same strength.
PG is more viscous than water, but is a lot less viscous that VG. This means PG is less thick and can flow quicker than VG. E-liquids with a higher PG will absorb much faster into the coils wick and be less susceptible to dry-burns or dry hits occurring.
For those looking for the brightest flavour, most optimized throat hit, and efficient wicking, a high PG juice may be the best choice.
Flavouring and nicotine are main contributors to coils turning black and becoming unusable. Those mixing their own juice may consider using a high PG blend, because less flavour can be used with the same outcome when compared to a high VG juice.
This may not be ideal for everyone. Some find high PG E-liquids to be too irritating or harsh on their throat, and some even have a sensitivity or intolerance to PG. A higher VG juice should be considered if a high PG juice will not work. Distilled water can be used to thin out juices in place in PG in high VG E-liquids if they are not wicking efficiently.
VG is not as good of a carrier for flavours and nicotine. When compared to PG, flavours suspended in VG tend to be a little more sweet but muted. Nicotine suspended in VG tends to offer a lesser throat hit when compared to nicotine suspended in PG at the same strength.
VG is more viscous than PG. This means VG is thick like syrup and can't flow as quick when compared to PG. E-liquids with a higher VG will absorb much slower into the coils wick and be more susceptible to dry-burns or dry hits occurring. More time should be given between puffs, and chain-vaping should be avoided.
For those looking for a little less flavour, smoother throat hit, and "big clouds", a high VG juice may be the best choice.
As mentioned above, flavouring and nicotine are main contributors to coils turning black and becoming unusable. Using a high VG juice will only expedite the process, and if any sweeteners are being used coil life will be significantly shorter. Those mixing their own juice may consider using more flavour concentrate for a high VG blend, because more flavour is usually required for the same outcome when compared to a high PG juice. Do not expect long coil life when using high VG E-liquid, especially if using extra flavour.
This may not be ideal for everyone. Some find high VG E-liquids to be too irritating or heavy on their chest or lungs. A higher PG juice should be considered if a high VG juice will not work. Distilled water can be used to thin out juices in place in PG in high VG E-liquids if they are not wicking efficiently.
The benefits and limitations with PG and VG may seem confusing, but it isn't as complicated as it seems. Staying within ±10% of a 50/50 blend will work with the majority of devices. Lower powered devices using a higher nicotine level may benefit from using 60% PG and 40% VG. Higher powered devices using lower nicotine level may benefit from using 40% PG and 60% VG.
Going beyond 60% PG or VG would be considered the "extreme" side of vaping for special circumstances in most cases.
70% + VG is considered high or Max VG but can be as high as 80-90% VG. Short coil life and muted flavour should be expected. Be sure to allow plenty of time between puffs to allow the thick E-liquid to saturate the wick properly.
70% + PG is considered to be a lot of PG for modern vaping. Slightly extended coil life as well as more flavour and more throat hit from nicotine should be expected. Be sure any pre-made coils are designed for high PG juices.
Since 2012, All Day Vapes' "Standard Blend" for House Blendz has been 60PG/40VG. This blend offers an ideal balance of flavour, throat hit, vapor exhale and coil life, and most customers seem to agree.
The majority of customers using this blend tend to be using medium to high nicotine levels (6-18mg/ml) at a lower power level (usually under 15W), although some customers use the 60PG/40VG blend with lower nicotine levels (0-6mg/ml) with sub-ohm coils at 50W or more.
For those that find the 60PG/40VG blend to be too flavourful, harsh on the throat, or are just looking for a bit more vapor on the exhale, it is often suggested to try switching the numbers of the "Standard Blend"and go with a blend of 40PG/60VG.
This blend will be slightly duller/muted compared to the "Standard Blend" but still offers plenty of flavour, and what it lacks in flavour will be made up for with an incredibly smooth vape and a healthy exhale of vapor without being too heavy irritating on the chest or lungs. If no sweeteners are used the coil life shouldn't be significantly altered, but will be more susceptible to dry-hits from chain-vaping when compared to the "Standard Blend".