Safe, stable, non-toxic and recyclable cooling agent compositions comprising solid particulate compounds undergo an endothermic process when mixed with water such that the resulting mixture is useful for cooling surfaces, liquids and solids. The mixtures include ammonium nitrate in an amount of at least 45 wt % of the mixture. Total nitrogen-containing salts exclusive of phosphates are present in an amount less than 68% by weight of the composition. A phosphate salt is also present in an amount as needed to stabilize the composition against detonation. A balance of additional salts is formulated to provide the mixture with a cooling capacity of at least 240 kJ/kg of the mixture.