Originally Posted by Coyotero
I've not worked personally with copper to any extent, but I've been led to understand that at high temperatures (Really higher than the hookah should get) toxins (Zinc maybe?) can be released in gaseous form.
However, I am no expert in the matter.
if the copper was an alloy and not pure copper then that would be possible but AFAIK only special industrial applications use alloys of copper that do not fall into brass or bronze. the zinc in brass can fume off (and when you silver solder/braze it you get copper "plating" which is more so the zinc vaporizing off leaving the copper on the surface). for the most part though to the best of my knowledge in industry "copper" is pretty much always 99.9% pure