Propylene Glycol (PG) is a man-made chemical derived from petroleum. At cooler temperature, PG is stable; but at higher temperatures, like in vaping, it tends to oxidize forming constituents like propinaldehyde, lactic acid, pyruvic acid and acetic acid3. According to the Lung Health Institute, PG is a known irritant to the pulmonary tracts4

This substance is the most common component used in e-cigarettes today. It forms the base in which flavor additives, CBD, and – in the case of smokers – nicotine, are suspended.

When vaporized, the PG carries its other contents into the user’s mouth and lungs, providing the CBD (or nicotine) “hit.”

PG, however, isn’t “healthy” just because there’s no combustible material involved when smoking it.

According to Dina Maron of Scientific American, the Food and Drug Administration (FDA) considers PG as relatively safe for consumption as a food additive5.

It’s also used in cosmetics and other products; however, there is little research about its effects when inhaled as an aerosol – which is the case with vaporizers.

So is PG dangerous?

Many organizations are trying to find the answer. The problem is that e-cigarettes are new, making long-term studies impossible until a few years from now. Several studies will surface up very soon and clarify more to clarify more about vaping.

A study from the Centers for Disease Control (CDC), however, shows inconclusive results with animal testing6. Researchers exposed mice to high concentrations of PG for extended periods of time to observe the possible negative impacts it could possibly have on the body. Results were inconclusive.

Since people who vape just inhale the PG in short concentrated bursts for a few minutes, researches don’t actually recreate an e-cigarette experience.

So, that leaves PG in the unknown when it comes to health. Until we have solid, long-term, peer-reviewed data, this is an area that so far remains unknown. Sadly, this could be at the cost of public health.

For further information, please refer to the following research reports:
Exposure to electronic cigarette vapors affects pulmonary and systemic expression of circadian molecular clock genes and Toxicology of E-Cigarette Constituents

Allergies from PG

One well-established issue with PG is its potential to cause allergic reactions. Vaping blogs and publications often mention this problem.

Susceptible individuals often feel symptoms ranging from a scratchy throat to sinus problems, headaches, and even feelings of nausea.

In extreme cases, PG can even cause numbness in the face and tongue as well as swelling and redness in these areas.

Expert Opinion on PG AND VAPING SAFETY