Propylene Glycol and Vegetable Glycerine
Propylene glycol - why is it used in e liquid?
One of the main reasons that propylene glycol is added to e liquid is that liquid nicotine and flavorings alone produce no visible vapor. The production of vapor is important for two reasons. Firstly, it acts as a vehicle for delivering nicotine into the lungs and secondly, because vapors enjoy the feeling of inhaling and exhaling something that visually resembles cigarette smoke.
So, to ensure a satisfying cloud of vapor, propylene glycol (PG) or vegetable glycerine (VG), both virtually odorless and colorless syrupy liquids, are added to the mix. Do note that despite scaremongering by individuals that don't know the facts, PG is not the same formulation as a similar-sounding product used to make radiator fluid or car anti-freeze - in fact it's widely used all over the world, everyday.
Propylene Glycol in other products
BP or USP* approved propylene glycol is used in cosmetics, toiletries, food colorings, cake mixes, salad dressings, soft drinks and more. It's also used in the smoke/fog machines found in theaters and nightclubs.
Are there any known side effects to vaping propylene glycol?
Occasionally, a few number of people using an electronic cigarette for the first time will complain of a sore throat, muscle pains and strong-smelling urine when first using an electronic cigarette.
Propylene glycol is a humectant (attracts moisture) which can dry your throat and leave it feeling sore. PG is converted to lactic acid in the body and it's this that causes the muscle aches that some people may experience from time to time.
Most people find that drinking more fluids helps to flush the lactic acid through the body more quickly. The sore throat should disappear on its own within a day or two, although increased fluids can help here too.
THE SIGNS OF AN ALLERGY TO PROPYLENE GLYCOL
If symptoms persist however, it may be that you are allergic to propylene glycol. Some people don't even realize they have an allergy to PG until they use an electronic cigarette with PG-based e liquid for the first time. Allergy symptoms may include night sweats, body rash, diarrhea and a dry, irritated or sore throat.
If you suffer from any of these symptoms, we recommend you seek the advice of your GP and switch to a VG-based e liquid.
Allergic to PG? Try VG instead!
Luckily, if you're allergic or sensitive to propylene glycol there is an excellent alternative – e-liquid made with vegetable glycerine or based on 50/50 ratio of PG/VG or e.g 30/70 PG/VG(ask your supplier for a VG-based e liquid). VG does the same job as PG and in fact, because VG appears to produce more vapor, many electronic cigarette users prefer it. PG Produces more flavour though and the more VG you add the less flavour a product may have depending on flavour mixture.
WHAT IS VEGETABLE GLYCERINE?
Vegetable glycerine, usually referred to simply as glycerine (and often abbreviated to VG by folks on the ECF), is a clear, virtually odorless viscous fluid which is slightly thicker and sweeter than propylene glycol. USP or BP approved glycerine is used in more than 1500 applications, many of them as additives to food and drink.
Other terms for vegetable glycerine
VG: A simple abbreviation of vegetable glycerine.
Glycerin or Glycerine: Small bottles of glycerine can be found in the home baking section of most supermarkets, next to the food coloring and flavorings.
Glycerol: Important Note: Be very careful not to confuse glycerol with glycol...similar names, different things!
*Only USP (United States Pharmacopeia) and BP (British Pharmacopeia) approved propylene glycol and vegetable glycerine should be considered food safe.
Possible Side effects of Vegetable Glycerin
Vegetable glycerin (aka glycerol or glycerine) is labeled as a safe substance by FDA, but there are still some risks associated with its use. Allergies to palm or coconut oil, as well as to any of the glycerin’s compounds, are the most frequently reported side effects. Other side effects include skin reactions after prolonged exposure to the substance, irritation of the mucus membranes, swelling tongue, upper respiratory tract infection (in case of prolonged inhalation), nausea and/or diarrhea (after ingesting large quantities of substance). These side effects are however restricted to a small group of people and the probability to experience one or more effects listed above is extremely low.
PG & VG USP/BP has a shelf life of more or less two years when stored below 40°C (104°F) in closed containers away from sources of ultraviolet (UV) light.