Safe Step 3300 rock salt/halite ice melt rock salt is the most economical ice melter. Made up of 100 percent rock salt/sodium chloride. All deicers can accelerate surface damage to concrete, since they increase the number of freeze-thaw cycles. Poor quality concrete is especially susceptible to damage. However, the hazards associated with slippery surfaces must be weighed against the potential of surface damage. Use this product only on good quality, air-entrained concrete for cold weather climates. Do not use on concrete that is less than one year old, has exposed aggregate, is precast, stamped, pre-stressed, chipped, cracked, spalled or weathered; or on stone, brick, mortar joints or wood. Not intended for melting ice on roofs, gutters or in downspouts.