As an alloying compound, adding chrome provides colour, hardness, hygiene, permanence, strength and resistance to corrosion, decay, temperature and wear. Chrome’s high melting point (2,150°C), low coefficient of expansion and very high thermal conductivity allows its use in foundry sands. The wear resistance, hardness, low coefficient of friction and brightness of chrome (in the form of acidic chromate or dichromate solutions) allow the electrodeposition of decorative, functional and engineering plating on metals. The mordant and fixative properties of chrome compounds are used to preserve wood from decay and damage by fungi, insects, termites, etc. Chromium (III) salts are also used in leather tanning. Its high melting point and resistance to heat make chromite refractory grades an ideal, cost-effective material, used in blast furnaces, cement kilns and metal casting. Compounds of chromium are also used as catalysts. Trace elements of Chromium (III) or trivalent chromium are required in the human body to metabolise lipids and sugar. Today, chromium is used in many dietary supplements. Chrome’s corrosion resistance makes steel stainless. In contact with air, chromium spontaneously forms a very thin, continuous and stable oxide film on the steel’s surface. This film renders the surface inert to chemical reaction and is passive. Chromium oxide mixed with other elements is used as a pigment in paints.