Just to be clear, if "we" is the engineering community then no we have not moved on from brass. It is used extensively in both breathing systems and in potable water systems. It is used in hospitals, restaurants, and other life critical applications. As for stainless being benign IN the human body, that is now being examined more closely, and this is what the NIH is saying; "...corrosion of implants can lead to the release of the biologically active hexavalent chromium into the body. This chromium is rapidly reduced to trivalent chromium in cells." The issue with hexavalent chromium being reduced to trivalent chromium in cells is that normally trivalent chromium is not transported into cells. Once it is in the cell, it creates haptens that trigger immune response, which is the start of a lot of problems. Also, according to the stainless manufacturers themselves, they state that "...heat and dust generating operations can generate airborne Cr+6, such as but not limited to: welding of stainless steel or chromium coated material, plasma cutting of stainless steel, and grinding and polishing." Welding and plasma cutting are clearly out of our temperature range, but grinding and especially polishing are well within our range. To offer a blanket statement that stainless is safe and brass is not entirely true, there is no evidence at this point that one is safer that the other in this application.