1.1 What is propylene glycol?
Propylene glycol is a synthetic liquid substance that absorbs water. Propylene glycol is also used to make polyester compounds, and as a base for deicing solutions. Propylene glycol is used by the chemical, food, and pharmaceutical industries as an antifreeze when leakage might lead to contact with food. The Food and Drug Administration (FDA) has classified propylene glycol as an additive that is “generally recognized as safe” for use in food. It is used to absorb extra water and maintain moisture in certain medicines, cosmetics, or food products. It is a solvent for food colors and flavors, and in the paint and plastics industries. Propylene glycol is also used to create artificial smoke or fog used in fire-fighting training and in theatrical productions. Other names for propylene glycol are 1,2-dihydroxypropane, 1,2-propanediol, methyl glycol, and trimethyl glycol.
Propylene glycol is clear, colorless, slightly syrupy liquid at room temperature. It may exist in air in the vapor form, although propylene glycol must be heated or briskly shaken to produce a vapor. Propylene glycol is practically odorless and tasteless.
PG = propylene-glycol when used as an antifreeze in Marine and RVs it’s colored PINK to show it’s FOOD safe and can be used in drinking water lines to protect against freezing. It’s also use in refrigeration systems where a leak could contaminate food supplies for the same reasons it’s FOOD SAFE.
PEG = polyethylene-glycol is the Toxic green stuff found in Automotive Antifreeze and even it is sold and used as a Vape Fluid under the guise of Cannabis infusing. ( See PEG 200&400 )
If you look you’ll see all my recipes have 1% or more of PGA (Pure Grain Alcohol) in my case it’s 151-190 proof EverClear
Works as both a fine carrier for additional adulterants like THC-CBD and helps enhance flavors in a high VG mix as @Maureeenie has noted.
Cross posed on Alcohols as diluents.
I knew it’d been covered.
So does gasoline and alcohol and dozens more substances.
PG isn’t used as a antifreeze in mixes, so I don’t feel a need to classify it as such when used in vaping. If I use it as a de-icer or such then I’ll say antifreeze.
We’re going nowhere very fast here. I use PG and I’m guessing you use antifreeze in your mixes. I respect how you define this flavor carrier. Maybe you can get @daath to change PG to antifreeze in the Calculator so it will be understood by the masses.
No, I use PG also. I call it PG. When someone says “don’t you know that stuff has the same stuff as anti freeze in it?” I just own it and say “yeah, I know.”
Propylene glycol is not Ethylene glycol, the principal component currently used in automotive antifreeze.
Glycerol, IE: Vegetable Glycerin, was once widely used for automotive antifreeze.
Glycerol was historically used as an antifreeze for automotive applications before being replaced by Ethylene glycol, which has a lower freezing point.
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).
Propylene glycol
Propylene glycol is considerably less toxic than ethylene glycol and may be labeled as “non-toxic antifreeze”. 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]
PEG400 is quite expensive now. I bought mine off Amazon for $18/liter. I haven’t used it yet because I was saving it for usage with certain herbal extracts. PEG is not ethylene glycol. The “poly” 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 I’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 haven’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 doesn’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 haven’t seen a lot of studies on vapor phase pg or anything else we mix with, but, to maximize safety I’d say using AG is probably safer…but this guy ain’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, I’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 cocktails…but there is a lot of study on aerosols of the main components that we vape. Knowing what is known and what isn’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 you’re always in a position of power. That’s scientist 101.
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 doesn’t suit my tastes. You know how when you have wicks running dry there’s that little harshness you get right before a dry hit? That’s what I’m getting from it. I’m curious to know if anyone else has had this experience.
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