Vapor Phase Corrosion Inhibitors (VpCI) manufactured by Cortec Corporation are used to protect metals against corrosion. When a VpCI source is introduced into an enclosed space, it emits VpCI molecules that continue to vaporize until they saturate the enclosure and the source's vapor pressure reaches equilibrium. VpCI molecules are attracted to metal where the positive and negative components of the molecule adsorb onto the anodic and cathodic sites of a corrosion cell inhibiting the occurance of corrosion.