VCI stands for Volatile or Vapor Corrosion Inhibitors. ZERUST® applies VCI technology to inhibit corrosion on metal surfaces. VCI film is packaging that generally consists of polyethylene film that has been impregnated with chemical formulations that are unique to each manufacturer. While the underlying formulations can vary significantly, the finished products function similarly in that they release very low concentrations (typically in parts per ten-thousandth) of invisible corrosion inhibiting vapors into the surrounding air. The vapor molecules subsequently condense onto exposed metal surfaces and form a molecular corrosion shield that can protect against rust and other forms of corrosion for many years. Typical service life is up to three (3) years and even longer in some cases. When the VCI packaging is later removed, all vapor corrosion inhibiting molecules rapidly evaporate. This leaves the metal parts clean and ready for immediate use.