Chromate conversion coating is a type of conversion coating applie to passivate aluminium, zinc, cadmium, copper, silver, magnesium, tin and their alloys to slow corrosion. The process uses various toxic chromium compounds which may include hexavalent chromium. The industry is developing less toxic alternatives in order to comply with substance restriction legislation such as RoHS. One alternative is trivalent chromate conversion which is not as effective but less environmentally damaging.