Volatile corrosion inhibitor (VCI) liquids protect metal surfaces from rust and damage. They are formulated to release volatile molecules that create a protective layer on the metal, inhibiting corrosion by preventing the contact of metal surfaces with moisture, oxygen, and other corrosive elements.

VCI liquids contain a blend of corrosion inhibitors, including organic compounds such as amines, organic acids, and salts. These compounds have a vapour pressure at ambient temperatures, allowing them to evaporate and form a protective atmosphere around the metal surfaces.

When the VCI liquid evaporates, the inhibitors form a thin molecular layer on the metal surface, which acts as a barrier against corrosion. This layer inhibits the electrochemical reactions that cause corrosion by either passivating the metal surface or neutralizing the corrosive species. Volatile corrosion inhibitors protect metal parts and components during storage, transportation, and other applications where metals are susceptible to corrosion.