You need to be very careful when you use the term "inhibited" glycol. Example:
Look at
www.InhibitedGlycol.com. This site sells Inhibited Glycol for the corrosion protection of metals. You do not want to use this product.
Propylene Glycol contains inhibitors that allow it to be consumed. Please ignore the phrase Inhibited when dealing with Glycol. You dont want to confuse someone else. There is one company out there talking about food chill inhibitors. No one using this term with glycol. The difference in Propylene Glycol is certification on manufacturing and packaging.
You want to use a Propylene Glycol that is Food Grade..
FoodGradePropyleneGlycol.com. Also, check that it contains that phrase USP. There are many other sites out there. This means it was certified for food use and final packaging was perform in a class 8 clean room. Most internet sellers repackage it internally and the product does not meet this certification. They simply do not understand the law. A way to verify this is to ask for a kosher certificate. If the kosher certificate matches the label on the bottle. This means a rabbii came out to view the packaging. All you are as safe as you can get when purchasing PG off the internet.