Is propylene glycol bad for humans?

Answer 1

Propylene Glycol USP grade is safe for human consumption, including inhalation. It is used as a germ killer in both solid and gas forms. It's in your prescription drugs. It's in your cosmetics and soaps. It's in your food. It's in your water. It's in tobacco products. It's used in fog machines. It's even in biodegradable antifreeze.

All the Material Data Safety Sheets I've found on PG only list a mild respiratory irritation when inhaled as a vapor.

Long term exposure is a different story. I haven't found anything on that, but the e-cig users who inhale PG vapors all the time don't report having any problems so far.

Added:

I found the medical resources on that question:

http://www.ncbi.nlm.nih.gov/pubmed/18158714

http://jpet.aspetjournals.org/content/91/1/52.abstract

Answer 2

Many studies show that propylene glycol is relatively safe for human consumption and is non irritating to skin. A huge amount of this chemical would be needed before toxicity would occur. It should however be avoided when possible because it is a chemical and natural foods and additives are always more healthy for the body.

Answer 3

If you sit there and drink a quart of it, it's not too good for you. Wikipedia lists 26 different uses for propylene glycol, and 16 of them involve putting the chemical either on or in humans. The FDA classifies it as "generally recognized as safe for use as a direct food additive."

Answer 4

Propylene glycol is heated in theatrical fog machines to produce artificial fog, and is generally regarded as safe for this usage. It is somewhat irritating to the eyes, though that's primarily the liquid form and not the vapor, and a few people do seem to have an allergic-like reaction to it.