I've been vaping for over a month now, and I can easily say that there is still a lot of information out there that I still don't know. One of those tidbits of information was the ingredients in e-juice. Sure, they are listed on the bottle for all to see, but it is one thing to know what is in something and another to understand what that ingredient really is or does. I've been doing some research into what e-juice is and why it is made the way it is and I think that I have gained some insight into the anatomy of an e-juice.
Most e-juices will be made of variations of the same 3-5 ingredients. They are a base (usually PG, VG, or a mixture of both), water, flavoring, and nicotine. The folowing will outline and anylize the different parts of the solution. The most confusion and misunderstanding seems to come from the actual base of the liquid, so we will start there.
E-Juice Base
As stated above, a base of either propylene glycol (PG) or vegetable glycerin (VG) or both is used. (Polyethylene glycol was once used as a base, but use of it was mostly discontinued over wide-spread concern over its effects on health.) These compounds are used as a base due to their hygroscopic abilities. Being hygroscopic, they can draw and hold the water molecules from their surrounding environment that then gets turned into vapor. (This also means that they can draw water out of your body when you vape too, so be sure to drink plenty of fluids!) The PG and VG also help to hold the ingredients in the e-juice solution together, so that they don't separate. While propylene glycol and vegetable glycerin both achieve the same end goal in e-juice, the two are are not the same overall, so let's take a closer look at each one:
- Propylene Glycol - Propylene glycol is an organic compound of carbon, hydrogen, and oxygen, classified as a double alcohol, with the chemical formula C3N8O2. PG is colorless and tasteless. It is made as a result of a reaction of propylene oxide and water. It is generally recognized as safe by the FDA and there is no evidence of PG being carcinogenic or genotoxic. It is non-corrosive, has very low volatility, and has very low toxicity. Large quantities of PG (much larger then even a day's worth of vaping) must be taken to give cause for even small health concerns. It is so safe, in fact, that the EPA has approved it for inhalation and it has been used as a base in inhaler and nebulizer solutions since the 1950's. Propylene glycol is easily metabolized by the body's normal processes and it is broken down into pyruvic acid, acetic acid, and propionaldehyol. Of the three, only propionaldehyol has the potential to be dangerous, but it is present in such small amounts for any concerns to be negligible. As well as Asthma medications, PG is also traditionally used as a humectant, a solvent, and as a preservative in food and tobacco products and in oral, injectable, and topical medications.
There is one other use for PG, and this use has garnered propylene glycol a bad name with some folks. It can also lower the freezing point of water, so it is often used as an ingredient in certain kinds of anti-freeze. I say certain here because people seem to have failed to see that the anti-freezes that PG is used in are all non-toxic and environmentally friendly. In fact, because it is so non-toxic, it is the ingredient of choice for RV and marine anti-freezes.
- Vegetable Glycerin - Vegetable Glycerin is an organic compound of carbon, hydrogen, and oxygen, classified as an alcohol, with the chemical formula C3H8O3. In the United States, it is also classified as a carbohydrate as it provides calories, but does not provide fat or protein. VG is thick and has a sweet taste. It is made from vegetable oil, often palm or coconut, that is heated, with water, under pressure. It is often created as a side product of soap making. VG is one of the most benign of all organic liquids. It is hypo-allergenic, non-carcinogenic, non-mutagenic, and non-teratogenic. Vegetable glycerin is often used in food products (often with the name glycerol) as it adds sweetness wile adding very few calories. It also does not contribute to tooth decay and it has less of an effect on blood sugar levels as it is slower to metabolize then sucrose. VG is metabolized through beta-oxidation and the process produces carbon dioxide and water. It is also used in topical remedies for psoriasis, rashes, burns, bedsores, and cuts as well as in cough medicines (as it has soothing properties). It is also used in laxatives, suppositories, and to treat gum disease. VG can also be used to lower the freezing point of water.
In e-juices, propylene glycol has become more popular then vegetable glycerin as it is the thinner of the two. (Although VG is chosen over the two as the organic option.) Being thinner, it is thought that PG bases are more easily absorbed by the wicks, leaving less chance of a dry puff. Using PG over VG can also help extend the life of your atomizer as the thicker VG can leave more gunky buildup on it. Propylene Glycol also carries certain flavors better as the sweetness of vegetable glycerin can lessen the intensity of those flavors. The main trade-off though is throat hit vs visible vapor. PG will provide a much more intense throat hit, simulating the effects of smoke hitting the back of your throat, while VG provides a much larger cloud of visible vapor, also mimicking smoke. Because of these different perks, many manufacturers will use a mixture of both PG and VG in their e-juices.
Nicotine
It is important to note that while e-juice can contain nicotine, they don't have to. Traditionally, e-juices have varying levels of nicotine, usually at levels of 0mg, 6mg, 12mg, 18mg, 24mg, and 36mg. To help understand what this means, here is a chart that I pulled from Vaper Train:
0mg/mL Nicotine: This means that there is no nicotine in your E-Liquid mixture. Zero nicotine levels are usually ordered by people who have quit smoking but still have an oral fixation and use an electronic cigarette to satisfy it.
6mg/mL Nicotine: This level of nicotine is the lightest level offered. For people who wish to enjoy the smallest possible nicotine level while still enjoying a full E-liquid taste. This is commonly the last level in "stepping."
12mg/mL Nicotine: On the lower end of the spectrum, 12mg/ml is a comfortable level for people who prefer nicotine, but aren't heavy vapers. This level is also common for people who used to smoke light cigarettes.
18mg/ml Nicotine: This is the middle of the road in terms of nicotine. Most vapers who were former smokers enjoy this level because it delivers the perfect amount of nicotine in each vape.
24mg/ml Nicotine: This is on the high side of nicotine levels and is commonly preferred by people who were formally heavy smokers (about a pack per day). It has a noticeable nicotine level that many former smokers enjoy.
36mg/ml Nicotine: This is the highest concentration of nicotine that we offer our customers. People who prefer this level are usually former smokers with a serious addiction, usually meaning more than two packs per day.
Please note that these are just common levels of nicotine as there are many companies out there that offer nicotine at levels other then the ones listed (for instance, I purchased an e-juice with 30mg of nicotine from Sweet Vapes). It is also important to note that many tests have found nictine levels in e-juices that vary from what is printed on the bottle (this is one problem that regulation may fix, though I'm sure it would also create a host of other problems and changes).
Flavoring
While I am sure that the chemicals used in e-juices vary from vendor to vendor and flavor to flavor, only compounds approved by the FDA for use in flavoring food and drink should be found in e-juices!
That leaves us with our last ingredient, which is water. I'm pretty sure that we all know about water, so I won't discuss it in detail here! You can see though that despite arguments as to the safety of e-juices, nothing in them seems to be harmful (except maybe the nicotine, though when used like it is in vaping, it's effects are almost the same as using caffeine!). As long as you stick with reputable manufacturers, nothing other then these ingredients should be found!
