Unused ice melt is good for years with an unlimited shelf life. Safe Paw is a patented dual-effect compound. The liquid component starts melting ice instantly while breaking its surface tension. This allows the crystal core to quickly penetrate and destabilize the ice and speed up the melting process. All this while Safe Paw proprietary traction agent provides slip protection. Safe Paw attracts heat to make it even more effective Endothermic reaction takes advantage of a solar effect.