What is E-liquid? Is it Safe? A complete guide on the ingredients and safety of E-liquid


If you are new to vaping and you just bought you first vape pen you may be asking yourself “What is E-liquid?”. In this article we are going to explain what e-liquid is, the ingredients that compose e-liquid, and just how healthy it truly is.

e-juice-picsE-liquid or e-juice is the fluid that fuels your electronic cigarette. It Is what provides the flavoring and nicotine to the user. E-liquid is heated inside your E-cig and creates a vapor in which the user inhales which mimics traditional cigarettes. This is where the term “Vaping” Comes from. E-liquid is normally composed of four different ingredients. Each ingredient, is used in other applications in the consumer world. We explore each ingredient separately so we can get more information about the potential side effects of inhaling these substances. In this article we are going to look at vegetable glycerin, propylene glycol, flavoring, and nicotine and talk about the health risks when inhaling them.

VG (vegetable glycerin)

Also called glycerol, is a clear, odorless liquid produced from plant oils, typically palm oil, soy, or coconut oil. VG is most often be found in cosmetic products, lotions, and toothpastes. VG is not only safe for your skin and body, it is also considered safe for consumption, since it can be found in many fruits vegetables, and dairy products.

Vegetable Glycerin makes up the base of your e-liquid but can also be mixed with PG (Propylene Glycol). Many electronic cigarette users report a smoother hit when using a higher VG e-liquid. A higher VG mix will also create thicker clouds, and is smoother on the lungs. Since Vegetable glycerin is regarded as safe, less research is conducted on its long term side effects. However it is very unlikely that VG presents any harmful affects.

PG (Propylene Glycol)

Commonly mixed with vegetable glycerin to make the base of your e-liquid. Propylene glycol is clear, colorless, order-less, and tasteless. It is a liquid alcohol that is used as a solvent, in antifreeze, and in the food, plastics, and perfume industries. Propylene glycol was classified by the U.S  Food and Drug Administration as “generally recognized as safe” for use as a direct food additive. PG and VG are generally mixed in different ratios in e-liquid depending on your preference. PG has a stronger throat hit which many vapors enjoy.

People have been questioning how safe inhaling propylene glycol is for decades now. initially it was administered in hospitals as a treatment to help breathing. Currently however PG can be found in everything from ice cream, to  deodorant. If you look at early studies on propylene glycol is seems to show that there is little to no harmful effects when inhaling the substance. Other studies find that when PG is inhaled it may be a deterrent against influenza, pneumonia, and other respiratory diseases.


E-liquid usually has some form of flavoring added to it typically made of out food grade flavoring. Flavoring is what makes many people skeptical on the safety of E-liquid. The word “Flavoring” is sometimes used on a products ingredient list without any real description of what it is made with. This leaves the consumer questioning what’s actually in the product, and if it is safe.

Most flavorings in e-liquid are generally approved by the FDA for consumption, but aren’t tested for their harmfulness when inhaled. Does this mean that all e-liquid flavorings are unsafe? No, but you should always research what’s in your e-juice and who you’re buying it from.

There are known examples of flavorings in e-liquid that can be potentially dangerous.  The most popular was diacetyl which is used primarily as a butter flavor in popcorn and other products. The Harvard School of Public health found that the chemical flavoring diacetyl found in E-Cigarettes is linked to certain lung diseases primarily popcorn lung. Most of the cases of popcorn Lung however where in workers in microwave popcorn plants who were inhaling large amounts of diacetyl on a daily bases.

popcorn lung

A study published in the 2015 journal of Environmental health Perspectives showed that the chemical diacetyl was found in many types of e-cigarette juice flavors especial in candy and fruit flavors.

Dr.Michael Siegel, a professor in the department of community health sciences at Boston University School of Public Health pointed out that this Harvard study did not mention that regular cigarettes contain a lot more diacetyl then any e-liquid on the market. Siegel found that “daily exposure to diacetyl from smoking is 750 times higher, on average than exposure to diacetyl from vaping”. The risks of diacetyl exposure are far lower for vapers than for smokers. However According to Critical reviews in Toxicology, “Smoking has not been shown to be a risk factor in bronchiolitis (Popcorn Lung).

So if you vape you have a far lower chance of contracting popcorn lung from diacetyl then someone who smokes cigarettes. Also if you smoke cigarettes it is highly unlikely that you will ever contract popcorn lung.

This doesn’t mean diacetyl is completely safe in e-liquid. You should avoid buying e-juice that contains this chemical. The majority of e-liquid manufactures today are removing diacetyl from there recipes, and this chemical will most likely be completely fazed out of all e-liquids in the future.

The amount of flavoring in E-liquid is also extremely small, often only measuring between 1% and 2% of the entire make-up of the e-liquid. In comparison traditional cigarettes contain as much as 8% of flavor adding chemicals.

Even though only small amounts of chemical flavorings are used in E-liquid there needs to be more research done on their affects when inhaled. There is still so much we do not know about the long term health risks on these chemicals. Thousands of different chemical flavoring agents are used by E-liquid manufacturers. The only real way to be safe when picking an e-liquid is to look at the ingredients and be aware of what you inhaling.


nicotine-compositionNicotine is added to e-liquid for people who are trying to quit smoking cigarettes but want some form of nicotine. E-liquid however can be purchased without nicotine added. It has been known for decades that nicotine is dangerous in the sense of how addictive it is. This is what keeps smokers hooked and makes big tobacco companies rich. However scientists are still unsure if nicotine alone has any health risks. A study from 1996 tested the effects of inhaling pure nicotine on lab rat’s and, found no serious changes in the rats health. “our study does not indicate any harmful effect of nicotine when given in its pure form by inhalation.”

Nicotine may also have some health benefits. Cigarette smokers often report a greater sense of concentration. Studies have even suggested that nicotine improves brain function in people suffering from dementia, and could prevent Alzheimer’s.


There is no way to say confidently whether e-liquid is safe for long term use. All the ingredients in e-cigarettes by themselves are relatively safe and do not have harmful side effects when inhaled. The assumption can be made that if all these relatively safe ingredients are combined the concoction would be just as harmless. Until more research is done on the long term effects of electronic cigarettes and e-liquid we will not know if they are 100% safe. We can however confidently safe that vaping is much healthier then smoking traditional cigarettes.