CPV code 14731000 designates Chromium in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
14731000 is a leaf code — the most specific level of its branch — so it can be used directly as the main CPV code of a contract notice. If it does not quite fit, check the neighbouring codes under 14730000 (Chromium, manganese, cobalt, yttrium and zirconium).