Is Propylene Glycol safe to eat?!
Answers: Is it good for you?
Yes, it is commonly added to some processed foods. It's not "good" for you, but it's not bad for you either. It is closely related to ethylene glycol (antifreeze), which is not toxic either, but its metabolic byproducts are highly toxic (glyoxylic acid and oxalic acid). Propylene glycol's metabolism byproducts are pyruvic acid and acetic acid, which are harmless.
This is why ethanol (i.e. vodka, etc) is an antidote to antifreeze poisoning if given immediately. It competes with ethylene glycol to be metabolized by the liver, buying enough time for the body to eliminate ethylene glycol in the urine.
Ethanol is also an antidote to methanol poisoning. Methanol itself is not toxic but its metabolic byproducts formaldehyde and formic acid are.
Serious toxicity will occur only at extremely high intakes over a relatively short period of time. Like ethylene glycol, propylene glycol affects the body's chemistry by increasing the amount of acid. Propylene glycol is metabolized into lactic acid. Undiluted propylene glycol is minimally irritating to the eye. Patients with vulvodynia and interstitial cystitis may be especially sensitive to propylene glycol. Women struggling with yeast infections may also notice that some OTC creams can cause intense burning.