Safe Step 7300 melts ice and snow on contact. Features a powerful, self-initiating chemical reaction which generates heat so melting occurs even in exceptionally cold weather. 100% high purity calcium chloride instantly generates hear for immediate melting action. Melts ice down to -25 degrees Fahrenheit/-32 degrees Celsius. Won't leave a powdery residue. Safer when used as directed on air-entrained, cold-weather concrete that is at least 1 year old. Flakes can also be used for dust control. Use 1 cup (10 ounces) of ice melt per square yard and spread evenly, avoiding piling or overspreading. Remove resulting slush. Reapply ice melt as needed.