Cobalt is a compound that occurs in nature. It occurs in many different chemical forms. Pure cobalt is a steel-gray, shiny, hard metal. Cobalt is not currently mined in the United States. All cobalt used in industry is imported or obtained by recycling scrap metal that contains cobalt. It is used in industry to make alloys (mixtures of metals), colored pigments, and as a drier for paint and porcelain enamel used on steel bathroom fixtures, large appliances, and kitchen wares. Small amounts of cobalt naturally occur in food. In addition, vitamin B12 is a cobalt-containing compound that is essential for good health. Some important natural sources of cobalt in the environment are soil, dust, and seawater. Cobalt is also released to the environment from burning coal and oil, and from exhaust from cars and trucks.
Fate & Transport
- Cobalt enters the environment from natural sources and from the burning of coal and oil.
- Cobalt stays in the air for a few days.
- Pure cobalt does not dissolve in water, but some of its compounds do.
- Cobalt can stay for years in water and soil.
- It can move from the soil to underground water.
- Cobalt is taken up by plants from the soil.
- Everyone is exposed to cobalt at low levels in air, water, and food.
- People who live near hazardous waste sites containing cobalt may be exposed to higher levels of this chemical.
- Food is another source of exposure to cobalt.
- Workers may be exposed to cobalt in industries that process it or make products containing cobalt.
Cobalt has both beneficial and harmful effects on human health. Cobalt is beneficial because it is part of Vitamin B12. Cobalt has also been used as a treatment for anemia, because it causes red blood cells to be produced. Exposure to high levels of cobalt can harm your health. Effects on the lungs, including asthma, pneumonia, and wheezing, have been found in workers who breathed high levels of cobalt in the air. In the 1960s, some breweries added cobalt to beer to stabilize the foam. Some people who drank large quantities of the beer experienced nausea, vomiting, and serious effects on the heart. However, effects on the heart were not seen in people with anemia or pregnant women treated with cobalt.
Animal studies have found problems with the development of the fetus in animals exposed to high concentrations of cobalt during pregnancy. However, cobalt is also essential for the growth and development of certain animals.
The International Agency for Research on Cancer has determined that cobalt is a possible carcinogen to humans. Studies in animals have shown that cobalt causes cancer when placed directly into the muscle or under the skin. Cobalt did not cause cancer in animals that were exposed to it in the air, in food, or in drinking water. Studies on people are inconclusive regarding cobalt and cancer.
Tests are available to measure cobalt levels in the urine and blood. These tests are only accurate for up to a few days after exposure because cobalt leaves the body fairly quickly.
These tests are not usually performed in most doctors' offices because special equipment is needed to conduct them. These tests cannot determine if adverse health effects will occur from exposure to cobalt.
The Environmental Protection Agency (EPA) requires that discharges or accidental spills into the environment of 1,000 pounds or more of cobalt be reported. The Occupational Safety and Health Administration (OSHA) has set an exposure limit of 0.1 milligrams per cubic meter (0.1 mg/m3) for cobalt in workplace air for an 8-hour workday, 40-hour workweek. The American Conference of Governmental and Industrial Hygienists (ACGIH) has recommended an occupational exposure limit of 0.02 mg/m3 for cobalt for an 8-hour workday, 40-hour workweek. The National Institute for Occupational Safety and Health (NIOSH) has recommended an occupational exposure limit of 0.05 mg/m3 for cobalt for a 10-hour workday, 40-hour workweek.
Information excerpted from
Toxicological Profile for Cobalt 1992
Agency for Toxic Substances and Disease Registry
United States Public Health Service