PG and VG in e-liquids: what is really proven regarding safety

Propylene glycol (PG) and vegetable glycerin (VG) are the common carrier substances in e-liquids. Much has been written about them, often with two problematic extremes: either they are categorically considered harmless because they are also found in other products, or they are dramatized with fabricated temperature and pollutant figures. Neither approach is helpful.

Anyone who wants to discuss PG and VG seriously must acknowledge three things simultaneously: First, these substances are very common in everyday e-liquid use. Second, their use in food or cosmetics does not automatically mean that every form of inhalation is unproblematic. Third, according to BfR not harmless.

What PG and VG actually are

Propylene glycol is a dihydric alcohol, clear, almost odorless, and readily soluble in water. It's encountered more often in everyday life than you might think: in toothpaste, skin creams, as a humectant in food, and in fog machines for stages and events. VG, or vegetable glycerin, is also an alcohol, but thicker and slightly sweet. FlavourIt is used in baked goods, sweets, and soaps, among other things.

The fact that both substances are found in many everyday products is often used online as a safety argument. However, this overlooks a crucial difference: eating something or applying it to the skin is not the same as inhaling it. The lungs react to substances differently than the stomach or skin. This is precisely why food safety approval does not directly imply that vaping is safe.

What are PG and VG actually for?

PG carries flavors well and is often described as having a stronger effect on the throat. VG is thicker and contributes more to the visible aerosol volume. However, this doesn't automatically translate into quality. A "good" ratio always depends on the device used. Anyone who immediately draws conclusions about safety or insecurity based solely on a numerical ratio is oversimplifying things.

How the ratio changes the vaping experience

A higher PG content generally results in a more noticeable sensation in the throat, which some users describe as a "throat hit." This can feel familiar to former smokers because it's closer to the sensation of smoking a cigarette. At the same time, a e-liquid with a higher PG content tends to produce less visible aerosol.

A higher VG content reverses the relationship: more visible vapor, a smoother throat hit, but often slightly less flavor delivery. This can be more pleasant for users who prefer a gentler vaping experience. However, VG-heavy e-liquid is thicker, which can lead to wicking problems with some devices.

Many pod systems use e-liquid mixtures that are neither extremely thin nor extremely thick. However, this isn't a general medical recommendation, but rather a matter of device compatibility. The crucial factor is whether the e-liquid flows smoothly and the device is used as intended.

PG/VG ratio and device type

Not every e-liquid is compatible with every device, and that's not a problem. Flavournot a question, but a technical one. Pod systems Smaller devices typically use thinner e-liquids because their wicks and atomizer heads are designed for a specific viscosity. Using a very VG-heavy e-liquid in these devices can restrict wicking, which in turn increases the likelihood of dry hits.

More powerful devices with larger vaporizers often handle thicker mixtures better. If you're using a new device, you should first consult the manufacturer's instructions regarding the recommended mixing ratio. If in doubt, a balanced mixture can serve as a good starting point, from which you can adjust to your own preference.

What can be reliably said about safety?

• PG and VG are not a guarantee of safety: The fact that both substances are frequently used does not make vaping risk-free.
• Overheating is a real problem: If a device runs dry or tastes burnt, the risk of unwanted decomposition products increases.
• Irritations occur: Dry mouth, scratchy throat or coughing are reasons to check the usage and device settings.
• Product and use belong together: Not every e-liquid is equally suitable for every device.

The German Cancer Research Center It points out that the level of harmful substances in e-cigarettes depends heavily on the product and its use. This is precisely why blanket statements like "PG is safe" or "VG is the problem" are too simplistic.

PG intolerance: rare, but possible

A question that regularly comes up in forums: Is it possible to have an allergic reaction to PG? True allergies to PG are rare, but not impossible. More often, users report sensitivity, which can manifest as a persistent scratchy throat, skin irritation around the mouth, or headaches.

Anyone experiencing such symptoms who cannot attribute them to a new flavor or a faulty device should try a liquid with a significantly lower PG content. If the symptoms disappear, a sensitivity to PG could be a plausible explanation. However, only a doctor can provide a definitive diagnosis.

Important to note: Even if you have a PG sensitivity, switching to pure VG isn't always straightforward. High-VG e-liquids don't carry flavors as well and aren't compatible with every device. In this case, it's worth specifically searching for products that are suitable for your setup.

Dry hits and overheating should not be underestimated.

A burnt Flavour It's not just annoying. It's a warning sign. If the e-liquid isn't flowing smoothly anymore or the coil is nearing the end of its lifespan, you shouldn't just keep vaping. Ignoring a dry hit doesn't mean you're "inferior" to other vaping. Flavour"Experience", but a usage problem that should be ended immediately.

How to avoid dry hits

Most dry hits are caused by avoidable mistakes. A common classic: inserting a new coil and immediately starting to vape without giving the wick time to saturate. When using a new coil, it should first be saturated with e-liquid for a few minutes before activating the device.

Equally important: keep an eye on the e-liquid level. If the tank or pod is almost empty, the e-liquid will no longer reliably reach the wick. Regular refilling before the level gets critically low significantly reduces this risk. And if you notice that the Flavour If the vapor production decreases or appears slightly burnt, this should be taken seriously as an early signal and the vaporizer head should be changed instead of continuing to use it for "another day".

This is precisely where many online texts become unreliable: They use exact temperature limits or fixed pollutant levels that are simply not applicable to the everyday life of the individual user. For consumers, the more practical rule is much simpler: If the device is smoldering, scratching, or getting unusually hot, stop using it.

Irritation does not automatically mean serious damage, but it is also not "normal".

Many users report dry mouth, a scratchy throat, or a tickly cough. Such complaints don't necessarily indicate a serious problem, but they shouldn't be dismissed as a normal side effect of vaping.If irritation persists, the first things to check are the device, e-liquid, puff intensity, and frequency of use.

If symptoms persist or if breathing difficulties, chest pain, or a significant decrease in performance occur, a medical evaluation is necessary. A blog recommendation does not replace a medical assessment.

Something one would rather not say

General statements like these are not reliable:

• "50/50 is the ideal security ratio"
• "Above temperature X it becomes dangerous, below it it is harmless"
• "For every 1 ml of liquid, you should drink Y ml of extra water."
• "With nicotine salt, you automatically inhale less PG and VG."

Such formulas sound technical, but are too schematic in real-world use. Consumers benefit more from paying attention to product quality, device compatibility, and warning signs, rather than adhering to rigid online rules.

How the comparison to cigarettes should be classified

Those who still smoke often seek a clear answer: Is it all still better than tobacco smoke? The current Cochrane overview This shows that nicotine-containing e-cigarettes can help adult smokers quit. However, this should not be taken as a shortcut: "helps with quitting smoking" is not the same as "harmless to the lungs".

For PG and VG, this means that, compared to continuing to smoke, a complete switch can reduce exposure to many combustion compounds. However, this does not automatically make the carrier substances themselves unproblematic. This distinction is precisely what is missing in many sales texts.

What is legally valid in Germany

In Germany, legal nicotine-containing products are subject to, among other things, a certain regulation. upper limit of 20 mg/ml nicotine. Furthermore, products are subject to regulations regarding labeling and product safety. This is important, but it does not replace individual tolerance. Even a legally compliant product can irritate someone or be too strong.

Practically sensible handling of PG/VG issues

• Don't ignore any dry hits: Burnt Flavour This is a stop signal.
• Matching device and liquid: Not every very thick or very thin liquid is equally suitable.
• Take persistent irritation seriously: Don't simply "keep testing" if your throat or airways react persistently.
• Do not derive a false sense of security from other areas of application: Food, cosmetics, and inhalation are not the same thing.

Conclusion

PG and VG are the usual carrier substances in e-liquids. Nothing more can be deduced from that alone. Anyone who wants to be serious also has to address the uncomfortable truth: long-term inhalation is not something that can be relied upon with simple safety promises, and problematic use often doesn't start with some exotic study result, but with very practical issues like overheating or burning. Flavour and persistent irritation. That's exactly where consumers should start.

A notice: This article is for general information purposes only. E-cigarettes are not risk-free. If symptoms persist or breathing difficulties occur, medical advice should be sought.