Propylene glycol is sometimes confused with Polypropylene glycol spell check is not always our friend it seems. One is an alcohol the other is a plastic chemical compound. Then there is the Wikipedia entries and I quote:
Propylene glycol, also called propane-1,2-diol, is an organic compound with the chemical formula C3H8O2. It is a viscous colourless liquid which is nearly odourless but possesses a faintly sweet taste. Chemically it is classed as a diol and is miscible with a broad range of solvents, including water, acetone, and chloroform.
Sounds scary except a better way to say that is PG mixes well with water. I mean if you think its relevant to stretch out your supply of chloroform then your on the wrong website and researching the wrong industry… Duck tape and shovels are on aisle 12:)
PG is used in Juice production to help VG grab water faster. You inhale and it grabs water molecules from your mouth and lungs and you exhale and you see water vapor. PG has been tested in the normal California method of overdosing rats till they die only they didn’t using PG. Its one of the few attempts to cause cancer in the state of California that failed.
I will again quote the Wiki:
Serious toxicity generally occurs at plasma concentrations over 4 g/L in, which requires extremely high intake over a relatively short period of time, or when used as a vehicle for drugs or vitamins given intravenously or orally. It would be nearly impossible to reach toxic levels by consuming foods or supplements, which contain at most 1 g/kg of PG, except for alcoholic beverages which are allowed 5 percent = 50g/kg. Cases of propylene glycol poisoning are usually related to either inappropriate intravenous administration or accidental ingestion of large quantities by children. The potential for long-term oral toxicity is also low. In one study, in 1972, 12 rats were provided with feed containing as much as 5% PG over a period of 104 weeks and they showed no apparent ill effects; no data on offspring was offered. Because of its low chronic oral toxicity, propylene glycol was classified by the U. S. Food and Drug Administration as “generally recognized as safe” (GRAS) for use as a direct food additive, including frozen foods such as ice cream and frozen desserts. The GRAS designation is specific to its use in food, and does not apply to other uses.
What that states we tried every stupid way we could think of to cause harm using this substance and failed but because it has industrial applications we want to keep it sounding scary. PG is used in aircraft to lower the freezing point of water.
The Vaping industry to get away from the Marketing of PG as harmful despite all the scientific efforts that prove otherwise is moving to replace PG with Corn Syrup