In copper-bottomed cookware, can the stainless begin to thin and allow the copper to leech through? My potato pot has discoloration at the bottom that another post suggested might be just from overheating. If copper did leech through is that dangerous?
If it is like the pans I've used, the copper bottom is attached to the bottom of the stainless "bowl" - almost impossible to wear through unless you clean frequently with a sandblaster.
Leaching from a copper vessel might be dangerous if it were routinely cleaned violently back to bright metal, or used to cook strongly acidic foods. If copper vessels are used routinely for cooking, they form a passive layer on the surface, and do not present a huge problem as long as malachite (green) does not form in the cooking area.