E-liquids are made of four main different ingredients. A base which consists of Propylene Glycol (PG) and Vegetable Glycerin (VG), nicotine, and food grade flavorings. Sometimes a distilled water is added to make the VG e-juice thinner, but that’s a subject for another story.

In this article we’re going to take a look at two of the most common ingredients of e-liquid, the propylene glycol and vegetable glycerin. Both of them have different impact on vaping experience, and it’s important to know what they are all about in order to choose the right e-liquid for your needs and vape setup.

PG – Propylene Glycol

propylene glycolLet’s talk about PG-based e-liquid first because it’s the most popular ingredient of e-juice. Propylene glycol is made from propylene oxide, a byproduct of petroleum.

It has no smell or color and it doesn’t affect the flavor of e-liquid. What it does however, is provide a throat hit, which is a similar sensation in throat as you get with smoking traditional tobacco cigarettes. That’s why most ex smokers start vaping with high-PG e-juice which helps overcoming the addiction of tobacco.

PG is used in various items such as shampoo, coffee-based drinks. hair conditioners and styling products, and so on. You almost certainly come into contact with PG on a regular basis because it’s very widespread. This also means that it has been well researched and if it would cause any health problems, the scientific researches would find it out decades ago.

Propylene glycol is used in:

  • Pet foods
  • Asthma inhalers
  • Beauty and cosmetic products

VG – Vegetable Glycerin

vegetable glycolVegetable Glycerin is an odorless liquid produced from plant oils, usually from palm oil, coconut oil, or soy.

It’s thicker than PG which allows it to produce larger clouds of dense vapor when used in e-liquid. If you are a beginner in the vaping scene and you’ve seen someone producing large clouds, this has a lot to do with high VG e-juice among other factors.

Another difference compared to PG is the sweetness. VG has a sweet taste which makes e-liquid sweeter in general, and it makes other flavorings harder to detect. It also doesn’t provide throat hit and that’s why beginners usually don’t start with high VG e-liquid.

Vegetable glycerin is used:

  • As a sugar substitute
  • In various beauty products
  • Soap
  • Pet foods
  • Baked goods
  • Eye and ear drops
  • Toothpaste

How safe are they?

Before we start talking about how safe the PG really is, let’s clear up some myths first. “Is PG antifreeze? This is going to get us all killed!” No, propylene glycol is not antifreeze. It’s used as an additive for antifreeze to make it less toxic and dangerous if someone accidentally swallows it.

The FDA lists propylene glycol as safe as a food additive. It has a lethal dose of 6g per 1kg of body weight which is quite impossible to achieve with vaping (a 100kg person would have to vape over 1 liter of e-juice in a short period of time).

  • 2001 study tested effects of exposure of heavily concentrated PG vapor on 27 non-asthmatic volunteers. The result showed that PG had minimal effect on the test subjects.
  • An old 1947 study tested toxicity of PG vapor on monkey and rats. The animals were exposed to a heavily concentrated mixture of PG in span of 12 to 18 months. The autopsy of internal organs, including a detailed examination of lungs, shown that there was no effect of the PG.
  • A large study studied lung problems and health of actors exposed to theatrical fogs containing PG in a 2-year span. The result showed that there were no significant changes in lung function for any test subject exposed to various glycols.

Keep in mind that although PG is considered safe, it can cause allergic reactions for some people. The most common symptoms are headaches, sore throat, and nausea, but they are quite rare. If you experience any of those symptoms, it’s suggested to go with the high VG e-juice because VG causes much less allergic reactions.

Vegetable glycerin is also approved to use in many forms by the FDA, Health Canada, and several other organizations.

  • A study called SIDS initial assessment profile of Glycerol Citation found that Glycerol is of low toxicity when inhaled, ingested, or in contact with skin. It’s has a very low potential to irritate the skin and the eye and it possesses no genotoxic potential.

It’s also known that VG is much less allergenic than PG and that’s why many vapers who start seeing allergic symptoms from PG start using e-juice with higher VG ratios.

Different PG/VG ratios

Here’s what different PG/VG ratios in e-liquid feel in general. Keep in mind that at the end it most of it depends on the type of gear you are using for vaping, but this will give you a general idea on what different PG/VG ratios mean in practice.

  • 100% PG – Miserable vapor production, very strong throat hit.
  • 80/20 – Very little vapor production, still strong throat hit
  • 70/30 – Vapor production is starting to get better, still quite good throat hit
  • 60/40 – Vapor is starting to get denser, throat hit starts getting notably softer
  • 50/50 – A mixture of good vapor production and notable throat hit
  • 40/60 – Clouds are getting larger, and the throat hit is starting to fade
  • 30/70 – Great vapor production with very soft throat hit
  • 20/80 – Massive clouds without much notable throat hit
  • 100% VG – Massive and dense clouds, very little to zero throat hit, very sweet flavor

What PG/VG ratio to choose?

If you are in the process of quitting smoking, we suggest that you start with e-liquid with at least 50/50 PG/VG ratio in combination with MTL vaping setup. The throat hit is something most ex smokers are craving for and it’s going to be easier to stop stop smoking completely.

At the end, most vapers like to experiment with different PG/VG ratios. Some of us prefer high VG e-juice while some vapers prefer high PG e-juice. It all comes down to personal preference. Keep in mind that different vaping setups deal with different PG and VG ratios differently.