Unlike rock salt & potassium chloride, Peladow® calcium chloride readily attracts moisture from the atmosphere, allowing it to form a liquid brine very quickly and fan out beneath the ice, breaking its bond with the pavement. Other deicers lose their effectiveness quickly when they become diluted with water. But even when diluted to 20% concentration, Peladow® keeps working down to -4 degrees F. Penetrates & undercuts ice fast & keeps on working all the way down to -25 degrees F - long after other deicers have given up. Easier on concrete & vegetation. Doesn't leave powdery residue.