My perspective: I think you've firmly determined that some carbonyls are produced when coil temperatures get into and exceed the 450°F range. But have we established that these levels actually exceed those found in tobacco smoke? Have we established that these levels actually present a significant health risk? Let's not forget that carbonyls are far from the only (or the most potent) carcinogens in tobacco smoke. Let's not forget that most of us voluntarily indulge in various "carcinogens" on a regular basis in the form of grilled and processed meats.