Trivalent chromium electroplating baths

[cicididi]

Chromium is commercially electroplated from electrolytes containing hexavalent chromium, but many attempts over the last fifty years have been made to develop a commercially acceptable process for electroplating chromium using electrolytes containing chromium trivalent salts. The incentive to use electrolytes containing trivalent chromium salts arises because hexavalent chromium presents serious health and environmental hazards--it is known to cause ulcers and is believed to cause cancer, and, in addition, has technical limitations including the cost of disposing of plating baths and rinse water.
The problems associated with electroplating chromium from solutions containing trivalent chromium ions are primarily concerned with reactions at both the anode and cathode. Other factors which are important for commercial processes are the material, equipment and operational costs.