Does the RoHS directive ban all chromium?
A. – Chromium can exist in four states. Metallic, divalent, trivalent and hexavalent. In some compounds chromium is in the hexavalent state (valence of +6) and many of these compounds are hazardous. The current European RoHS directive bans the use of six substances, one of which is hexavalent chromium. The ban on hexavalent chromium targets primarily corrosion resistant coatings, such as the chromate conversion coatings applied to zinc plating. Metallic chromium found in stainless steel is not a RoHS substance.
