Frozen mugs - how do they work?

Question

Ok... those mugs you put in your freezer that freeze to keep your drink cold w/o ice... Obviously its stuffed with some sort of liquid or material that freezes in the freezer... duh, but what the heck is that stuff? Cuz it doesn't look like water?

Just wondering lol because i'm drinking some fruit juice from mine right now :)

Answer 1

It's a mixture of Propylene Glycol and water. It's similar to car antifreeze (Ethylene Glycol) but it's not toxic, so if it leaks, it won't poison you. It's so non-toxic, it's actually an ingredient in a lot of foods, used similarly as glycerin.

It's not pure propylene glycol, but mixed with water...this makes it less expensive as well as increases the ability to cool. Water transfers heat (or cool as the case may be) more effectively, so it cools your drink better than the glycol alone. -Apparently. Hope i helped :)