text: The first widescale use of VCIs can be traced to Shell's patent for dicyclohexylammonium nitrite (DICHAN), which was eventually commercialized as VPI 260.  DICHAN was used extensively by the US military to protect a wide variety of metallic components from corrosion via various delivery systems, VCI powder, VCI paper, VCI solution, VCI slushing compound, etc.
  Safety and health concerns as well as inherent limitations has led to the abandonment of DICHAN as a VCI. At present, commercial VCI compounds are typically salts of moderately strong bases and weak volatile acids.  The typical bases are amines and the acids are carbonic, nitrous and carboxylic.