Cobalt poisoning is intoxication caused by excessive levels of cobalt

Cobalt

Cobalt is a chemical element with symbol Co and atomic number 27. It is found naturally only in chemically combined form. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal....

 in the body. Cobalt is an essential element for health in animals in minute amounts as a component of Vitamin B₁₂

Vitamin B12

Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...

. A deficiency of cobalt, which is very rare, is also potentially lethal, leading to pernicious anemia

Pernicious anemia

Pernicious anemia is one of many types of the larger family of megaloblastic anemias...

. However in common with all elements and all chemical compounds, excessive cobalt can cause death. Even the name of the element reflects its toxicity; It was derived from kobold, the name of an evil spirit in German lore..

How cobalt enters the body

Exposure to cobalt metal dust is most common in the fabrication of tungsten carbide

Tungsten carbide

Tungsten carbide is an inorganic chemical compound containing equal parts of tungsten and carbon atoms. Colloquially, tungsten carbide is often simply called carbide. In its most basic form, it is a fine gray powder, but it can be pressed and formed into shapes for use in industrial machinery,...

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Toxicity of cobalt salts

The values of soluble cobalt salts has been estimated to be between 150 and 500 mg/kg. Thus, for a 100 kg person the LD₅₀ would be about 20 grams.