You know those “blue ice” freeze packs? The ones in heavy plastic that claim to be leak-proof?
I have one that leaked.
I now how a blue puddle in the bottom of my little igloo cooler. Actually, I had a puddle, now it looks like it dried out. Any ideas how to clean it up? What is that blue stuff, anyway?
We use those, too. And they leak. I don’t get the leakproof thing either. We use them for what they were made for, all they do is sit in our lunch coolers, so what in the world causes them to leak?
I use a wet paper towel to clean the cooler out after a leak. Try a little soapy water in there since it’s dried.
I’ve found that putting the ice pack in a ziploc bag or some such, keeps it from getting all over the cooler. Of course, the baggie will eventually leak, so you’ll have to change it periodically.
I have no idea as to what it is, other than messy. 
The gel packs are water, propylene glycol, methocel and FD & C blue 1.
MSDS for methocel, a.k.a. methylcellulose, a.k.a. the active ingredient in Citrucel. It’s basically inert, more or less, although it notes you shouldn’t get the powder in your eyes.
http://sargentwelch.com/pdf/msds/sch94605.pdf
MSDS sheet for propylene glycol. It’s a mild skin irritant, but not terribly toxic.
So yeah, clean up your Igloo with plain old dish soap and water, I’d say. You might need to let it soak to let the methocel re-hydrate so you can get it out of there.
The blue coloring is most likely to alert you that you have a leak, otherwise the active ingredients, which may range from toxic to merely unpleasant, could infiltrate foodstuffs unnoticed.
The ones i have actually specify the contents are “non-toxic”.
Thanks all - I have some scrubbing to do now…