You've seen it. That black dust all over your rotor that seeps out onto your rims. Like mold, or mildew. And you ask yourself, What the %#@& is this #@$%? Not that it will help that much, but there is a technical explanation for dusty pads. It seems some brake formulas use petroleum hydrocarbons as glues and binders. When your pads get hot they can give off a gas which coats your wheels in an oily, greasy film that everything sticks to. But this is only part of the story. As metallic formula brake pads heat up, the metallic particles become magnetized from the heat and friction causing a static charge that sticks to alloy wheels. Can dusty pads be prevented? In many cases, maybe. New formulas on the market will reduce dust; some more than others. For now there are low-dust pads, but no guaranteed 100% no-dust pads. Keep in mind that even low or lower dust pads will dust excessively if you have other brake problems or if your rotors were not replaced or resurfaced.