Nickel is a silvery-white, metallic chemical element that features high strength, malleability, ductility and resistance to corrosion. These properties make it excellent for strengthening metal alloys, most of which are with iron, and facilitate their being formed into wire, rods, tubes, and sheets. Close to 70 percent of total world nickel production is used in stainless steel, although batteries are one of the fastest growing applications.
Nickel is also an essential trace element in some plants, bacteria and fungi, and it it is also possible that it is an essential nutrient for bacteria residing in the large intestine of humans. However, it can be toxic in large amounts, with some nickel compounds classified as human carcinogens and elemental nickel metal classified as a suspected carcinogen.