They may also degrade the very roads that they're de-icing, plus they cause cars to rust and they have to be applied repeatedly throughout the winter. Even then, once a fresh layer of ice forms on the asphalt, drivers are stuck with it until the ice-spreading trucks arrive again. Scientists from China's Hebei University of Science and Technology (and other institutions) set out to address those shortcomings, starting out by developing a chloride-free acetate-based salt. Such salts are considerably less environmentally harmful than chlorides, they're less corrosive to steel and other materials, plus they work at lower temperatures.