Safe to use on concrete. Colorless and odorless. Safe for environment and vegetation. Melts down to -15 degrees Fahrenheit. Starts melting on contact. The combination of Calcium Chloride pellet, Magnesium Chloride pellet and Sodium Chloride makes Road Runner a fast acting ice melt at a reasonable price. Very few blends use premium pellets. The pellet actually allows the product to melt faster, longer and at lower temperatures.