Trivalent chromium, or chromium (III), is chromium in its +3 oxidation state, which means that it has a charge of +3 and can form up to three different bonds with other atoms. Trivalent chromium is present in many different compounds, including anhydrous chromium (III) chloride, which appears as a purple compound.
Trivalent chromium is the most common naturally occurring oxidation state for chromium and is naturally present in the environment. This element is also necessary in trace amounts for metabolic processes in the body, and most people experience low levels of daily exposure. Most exposure comes from consuming small amounts of trivalent chromium compounds in food and water or from handling items that have been treated with trivalent chromium compounds. Hexavalent chromium is much more toxic. The body can convert some hexavalent chromium into trivalent chromium, but high quantities cause burns and gastrointestinal and neurological effects.
Trivalent chromium compounds are available as one of the options for chrome plating. Chrome plating can be carried out with either trivalent or hexavalent chromium compounds. For chrome plating, trivalent chromium compounds are much less toxic than the hexavalent alternatives. The waste products produced by chrome plating with trivalent chromium are safer. Chromium (VI) plating can produce toxins, such as lead chromate.