It looks like Puron (the replacement for Freon) is non-toxic (and non-flammable), but it also wouldn't be a liquid at any temperature you'd need cooling at. I'

It looks like Puron (the replacement for Freon) is non-toxic (and non-flammable), but it also wouldn't be a liquid at any temperature you'd need cooling at. I'm guessing there are other chemicals which have vaporization temperatures in the 150-200 degree range, and are neither toxic nor flammable, but assuming ethanol works it has the advantage of being fairly easy to come by in a pinch.