Hexavalent Chromium refers to chemical compounds that contain the element Chromium in the +6 oxidation state that when inhaled, is recognized as a human carcinogen. This chemical is banned by the RoHS directive of 2011.
Hexavalent chromium (chromium(VI), Cr(VI), chromium 6) is chromium in any chemical compound that contains the element in the +6 oxidation state (thus hexavalent). Hexavalent chromium is key to all materials made from chromium. Approximately 136,000 tonnes (150,000 tons) of hexavalent chromium were produced in 1985. Hexavalent chromium compounds can be carcinogens (IARC Group 1), especially if airborne and inhaled where they can cause lung cancer.