This calcium chloride formula is exothermic, meaning it generates heat from within to penetrate through snow and ice. While powerful, it is safer and non-corrosive to concrete and pavement that has been properly set and cured. This snow and ice melt product begins working on contact and gets the job done 4x faster than rock salt and other chloride ice melt formulas! Green Gobbler's Calcium Chloride Snow & Ice Melt is effective in negative temperatures -- melting ice in conditions as low as -40 degrees. The perfect option for those who live in a location where it regularly hits negative numbers.