Aye, urea is what's in the "instant ice packs" now. It used to be ammonium nitrate, but most brands switched it to urea a few years ago - presumably for reason

Aye, urea is what's in the "instant ice packs" now. It used to be ammonium nitrate, but most brands switched it to urea a few years ago - presumably for reasons of "people could use the extremely nice, uncoated, very pure ammonium nitrate for nefarious purposes" (useful for explosives and methamphetamine manufacturing!)