Tag Archives: propylene glycol in E-cigarettes

The Final Word on Propylene Glycol vs. Polyethylene Glycol


I keep reading warnings, many by the uneducated masses of parrots populating the green face of the Earth and some by the supposedly educated, medical professionals of the world, which impress upon those being warned that the liquid used in E-cigarettes is also used in antifreeze, making it extremely toxic to human beings… and animals, too, allegedly.  The truth, of course, is both more complicated and simpler than the lies and misconceptions surrounding this volatile, semi-political topic based on the rising popularity of electronic cigarettes, purported to be a healthy alternative to “real” (analog) tobacco products.  This antifreeze scare is nothing new.  The most vehement of the anti-smoking gang (the ones who think anything cylindrical, brought to the mouth on a regular basis is a gateway drug to Marlboro Reds) immediately leapt upon the jugular of the first E-cigarettes to hit the First World and disected their ingredients until they found something, anything, that could be used to demonize them to the public who, ironically, were looking for a different way to quit smoking.  They found that one of the main ingredients in E-liquid was polyethylene glycol, which is used in antifreeze and is fairly toxic to humans in large quantities.  The E-cigarette industry answered by changing that ingredient to propylene glycol, a much safer alternative.  In fact, although propylene glycol (or PG) is used in antifreeze as well, it’s only used in RV and Marine antifreeze, colored pink to designate it’s non-toxic qualities.  Hence the picture above.

Here are a few facts about polyethylene glycol (the somewhat dangerous one):

  • Polyethylene glycol is, in fact, used in antifreeze because it lowers the freezing temperature of water.  It produces ethylene glycol when processed.
  • Ethylene Glycol has been known to be lethal in doses as low as 786 mg/kg.  Even the electronic cigarettes that DO utilize polyethylene glycol (PEG) come nowhere near this mark.
  • Laboratory studies on the inhalation of vaporized/aerosolized PEG all showed that inahlation did not, in fact, deliver lethal, or even harmful, doses of PEG to laboratory animals.
  • Antifreeze which uses PEG to lower the freezing point of water is generally dyed a blue/green color (we’ve all seen it on our driveway at one point or another) to indicate toxicity and danger.
  • When ingested (swallowed, not inhaled) PEG is metabolised first into glycolic acid, then into oxalic acid… which is dangerous.  This danger is present in PEG, but as stated above, not enough to cause harm when vaporized.

In contrast, here are some interesting points concerning propylene glycol (the harmless one):

  • PG is metabolised by the human body into chemicals that are naturally occurring in normal, human metabolic functions.  The resulting chemicals are pyruvic and lactic acids, both of which are quite normal in our bodies.
  • PG is listed by the Food and Drug Administration (Yeah, that’s right.  The FDA, otherwise known as the opponents to the E-cigarette industry) as GRAS (Generally Recognized as Safe).
  • PG is present in some antifreeze products, but is colored pink to make it readily recognizable as non-toxic.  This type of antifreeze is often found in boats and RVs.
  • In addition to being approved for human consumption by the FDA, PG is also approved for human inhalation by the Environmental Protection Agency (EPA).
  • Last but not least in the slightest, PG’s germicidal properties has been found to promote healthier human lung function by killing many of the germs and bacteria which take root in the lungs and make us sick with respiratory illnesses.  So, in short, PG is not only harmless, it also induces a state of increased healthiness.

PG is now used by the vast majority of E-juice manufacturers.  PEG was all-but-abandoned when all of this hogwash about antifreeze started causing the sheeple to panic, as they are wont to do whenever they read a headline with the form “Is _____ Really Healthy?”  As you can see by the above-mentioned evidence and scientific analyses, Neither PEG nor PG are actually unhealthy when inhaled.  Of the two, PG is slightly better, which is why most of the E-cigarette industry has switched from PEG to PG.  Of course, they also did so in an effort to shut the ANTZ (Anti-Nicotine and Tobacco Zealots) up… a move which ultimately failed because they have abandoned all attention to scientific evidence in exchange for a vendetta against the industry as a whole.

Please feel free to spread this around to all the skeptics you know.  Encourage them to do more research on their own, and at the very least to read through the sources listed below.  All I ask is that you give ejuiceconnoisseur.com credit as author.  Good luck and VAPE ON!!!!


-Propylene Glycol- Wikipedia

-Code of Federal Regulations

-Product Safety Assessment- Propylene Glycol

-Ethylene Glycol Toxicity

-Ethylene Glycol- Wikipedia

-Are Electronic Cigarettes Safe?

-A Germ-Killing Vapor

-Deposition and Fate of Inhaled Ethylene Glycol Vapor and Condensation Aerosol in the Rat

-Two-week aerosol inhalation study on polyethylene glycol (PEG) 3350 in F-344 rats.

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