Wonder what type ammonia was used in an Icyball?   While it's a very effective refrigerant the stuff is hateful to deal with. Probably why CFC refrigerants were developed. They might make the naturally occurring ozone hole a bit bigger or smaller (same as nature itself does😛), but they're also generally safe and won't burn, kill or blind you like NH3 will.   Having to handle anhydrous ammonia is the single biggest thing I DON'T miss about my old powerplant career!