One of the most appealing features of e-cigarettes is the elimination of many chemicals found in traditional cigarettes. You can still get nicotine in eLiquid, but Vapers make that a deliberate choice. eLiquid also frequently contains safe, food-grade flavorings, which leaves propylene glycol and vegetable glycerin (PG and VG) as the most common remaining e juice ingredients. Are PG and VG necessary in eLiquids? Are they safe? The answers are yes and generally.
Propylene glycol (PG) has something of a mixed reputation. Although it has been widely used for decades and has approval from the Federal Food and Drug Administration (FDA) for human consumption, its industrial uses cause some to believe it’s a dangerous toxin. In truth, PG is an organic compound, meaning it contains carbon, with very low toxicity. By itself, it’s a clear, thick liquid with a hint of sweetness. It’s also incredibly versatile.
PG is one of several ingredients used in making plastics and polymers. It also reduces water’s freezing point and so is used as a de-icer and in antifreeze. Contrary to alarmist thinking, adding PG to antifreeze makes it nontoxic by replacing the more dangerous ethylene glycol.
PG is frequently used in shampoo, lotion, toothpaste and cosmetics. It’s common in over-the-counter and prescription medications, including asthma inhalers, and it keeps many prepared foods moist. Note: The body processes PG much like sugar. In eLiquid, it’s a dispersant that helps vaporize and deliver liquid nicotine.
Some people do have allergic reactions to PG, and it can increase skin irritation in those with eczema. A mist containing PG may cause eye irritation or some respiratory tract discomfort. Yet risks generally only occur with very high, direct doses in a short period of time. There don’t appear to be any long-term risks with low doses.
Vegetable glycerin (VG) is similar to propylene glycol in being an organic compound that’s a thick, clear liquid with many uses. It’s nontoxic as well, and the FDA recognizes it as safe for human consumption. Note: VG is slightly thicker and sweeter than PG.
VG is a common ingredient in skin moisturizers, soaps and certain medications, such as cough syrup. It helps keep foods moist, and as a sweetener, VG has fewer calories than sugar. Additionally, glycerin is a component of nitroglycerin, which is both an explosive and a medication for heart conditions.
In eLiquid, VG serves the same purpose as propylene glycol: to help vaporize and deliver nicotine. It’s considered hypoallergenic, is easily metabolized, and it doesn’t irritate skin or eyes. Some people may experience dry mouth or dry throat as well as increased thirst when first using VG in eLiquid, but these symptoms are usually short-lived.
The choice between PG and VG in eLiquid
Since propylene glycol and vegetable glycerin serve the same purpose in eLiquid, and each is considered safe, why use both, and why do some people prefer one or the other?
The difference lies mainly in vapor production and throat hit. Vegetable glycerin is ideal for sub ohm vaping because it produces a lot of vapor, but it’s a little light on throat hit. Propylene glycol is the opposite: great throat hit but less vapor. Many eLiquid manufacturers try to find the perfect balance in blending various ratios of PG and VG together. Some also adjust the balance for Vapers who want a stronger or milder throat hit or different amounts of vapor.