Question about dilutants (and the Safety of PG, VG, PEG)

Is that so? I thought they were the same. Mind blown.

The most common water-based antifreeze solutions used in electronics cooling are mixtures of water and either ethylene glycol (EGW) or propylene glycol (PGW).

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Propylene glycol
Propylene glycol is considerably less toxic than ethylene glycol and may be labeled as ā€œnon-toxic antifreezeā€. It is used as antifreeze where ethylene glycol would be inappropriate, such as in food-processing systems or in water pipes in homes where incidental ingestion may be possible. For example, the FDA allows propylene glycol to be added to a large number of processed foods, including ice cream, frozen custard, salad dressings, and baked goods.

Propylene glycol oxidizes when exposed to air and heat, forming lactic acid.[9][10] If not properly inhibited, this fluid can be very corrosive,[citation needed] so pH buffering agents such as dipotassium phosphate and potassium bicarbonate are often added to propylene glycol, to prevent acidic corrosion of metal components. Pre-inhibited propylene glycol solutions can also be used instead of pure propylene glycol to prevent corrosion.

Besides cooling system corrosion, biological fouling also occurs. Once bacterial slime starts to grow, the corrosion rate of the system increases. Maintenance of systems using glycol solution includes regular monitoring of freeze protection, pH, specific gravity, inhibitor level, color, and biological contamination.

Propylene glycol should be replaced when it turns a reddish color. When an aqueous solution of propylene glycol in a cooling or heating system develops a reddish or black color, this indicates that iron in the system is corroding significantly. In the absence of inhibitors, propylene glycol can react with oxygen and metal ions, generating various compounds including organic acids (e.g., formic, oxalic, acetic). These acids accelerate the corrosion of metals in the system.[11][12][13][14]

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VG wont freeze but does slow to a crawl.

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I call gasoline expensive.

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I donā€™t know guy, I de-ice my lungs daily, donā€™t you? lolā€¦

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PEG400 is quite expensive now. I bought mine off Amazon for $18/liter. I havenā€™t used it yet because I was saving it for usage with certain herbal extracts. PEG is not ethylene glycol. The ā€œpolyā€ part is an important distinction.

Anyhoo, I hear it has more of a chemical taste to it than PG. The toxcity myth (for those that look, pg and vg are two of the most studied aerosols out there in humans) and the OSHA safety limits are equivalent to wading through a dense cloud 8 hours a day, 5 days a week, so it is myth as far as Iā€™ve been able to determine. I spend a lot of time implementing processes that expose people to vapors, so I tend to do a LOT of research on these topics. I havenā€™t seen too many studies on peg400 inhalation.

One thing I want to throw out is that a decent amount of pg we inhale is vapor while the vg is an aerosol. The PG is what boils (producing vapor) and that boiling atomizes the VG (thereby making an aerosol), which doesnā€™t boil at vaping temps. So when we look at safety, we need to consider the exposure to vapor as well as the aerosol. I havenā€™t seen a lot of studies on vapor phase pg or anything else we mix with, but, to maximize safety Iā€™d say using AG is probably saferā€¦but this guy ainā€™t getting rid of pg anytime soon nor am I particularly skeered of PEG400, but that is my personal choice after evaluation of the known info.

Ok, main thing I wanted to say is you can still buy peg400, its still used by those who vape herbal extracts, and there is a difference between vapor and aerosol. Beyond that, Iā€™d recommend those in doubt look at the available research and draw you own conclusions.

Sorry, long ramble almost over. Hope it stimulates curiosity and thought about what we are doing when we vape. A lot is not known about what we are doing inhaling these chemical cocktailsā€¦but there is a lot of study on aerosols of the main components that we vape. Knowing what is known and what isnā€™t is the duty of someone using this nic delivery method.

I also gotta agree with @TheTinMan1 that we need to own this. We are inhaling a chemical used in antifreeze. We are inhaling components of hair products and artificial sweeteners among many other things. By owning this it demonstrates the power of knowledge versus blissful/willful ignorance. Like vapor vs. aerosol, owning the knowledge is power. Remaining ignorant is a choice. Take your pick, I propose no judgement. We must do both all the time about much more than vaping. But picking what you know and acknowledging what you dont ensures youā€™re always in a position of power. Thatā€™s scientist 101.

Here ends the sermon.

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Great sermon ā€“ no disagreements. . .doesnā€™t really address the quality of vape you get from PEG 400 on the modern tech, which is all I cared about XD.

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PM me your address if you want and Iā€™ll send you 250ml in glass.

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Reviving an old thread because I only found very limited info here regarding Polyethylene Glycol (PEG 400) which I ordered by mistake thinking I was buying PG.

Oh well, vape on, right? Maybe not. Seems to me this stuff doesnā€™t suit my tastes. You know how when you have wicks running dry thereā€™s that little harshness you get right before a dry hit? Thatā€™s what Iā€™m getting from it. Iā€™m curious to know if anyone else has had this experience.

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Hello! What about PDO(propanediol) ? Here in Italy is a little hard to find a PDO for vape use, not at a good price at least, but I 'm a little curious about.

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(July 16, 2018):
ā€œPhysical and chemical assessment of 1,3 Propanediol as a potential substitute of propylene glycol in refill liquid for electronic cigarettesā€

We have developed complementary methods to characterize PDO as a e-liquid that may be applied to other formulating ingredients such as PG. These methods include thermal stability, pH determination by a rapid and simple method, aerodynamic features and flavor enhancing properties with a numerical predictive model to access to the associated properties such as solubility. To sum-up, our results indicate that:

  • PDO is doubtless stable upon heating when EC are used in recommended conditions (250 Ā°C).
  • PDO seems to have better thermal behavior showing less thermal decomposition by-products compared to PG and VG.
  • PDO seems to give to nicotine a more basic environment ensuring a 100% free base nicotine form, although once in the aerosol it could return to its protonated state.
  • PDO shows globally better flavoring properties than VG and PG, except for the case of the two terpenes limonene and menthol.
  • PDO seems to induce quite similar aerodynamic properties compared to usual aerosol features generated by the use of PG + VG refill liquid in electronic cigarettes.

.

(2018):
ā€œIs Propanediol a safer molecule than some other glycols in personal care and anti-aging biocosmeceutical products?ā€

(2005):
ā€œInhalation toxicity of 1,3-propanediol in the ratā€

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Wow. That was long. The references at the end of the article list no less than 51 scientific articles referring to studies involving inhalants and all things vape related. Good god thereā€™s a lot of research.
We should make all the politicians read every single one before they can make a single law.
At least that would keep them busy for a couple years while we continue to blow clouds.

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I ordered some peg400 for the purpose of helping my medical marijuana card carrying friends produce a vapable liquid out of concentrates like budder, shatter, live resin, was, etc. Theyā€™ve been very pleased with the results.
I have not however, used in normal vape rigs to administer nicotine. Iā€™m comfortable with vg/pg for that. The thc concentrates are mixed 1 to 2 with the peg400 so it has little to no effect on the end flavor of the thc liquid. The only thing I CAN say is that it produces less clouds than vg.

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