Cadmium (Cd) is a soft, malleable, bluish white metal found in zinc ores, and to a much lesser extent, in the cadmium mineral greenockite. Most of the cadmium produced today is obtained from zinc byproducts and recovered from spent nickel-cadmium batteries. First discovered in Germany in 1817, cadmium found early use as a pigment because of its ability to produce brilliant yellow, orange, and red colors. Cadmium became an important metal in the production of nickel-cadmium (Ni-Cd) rechargeable batteries and as a sacrificial corrosion-protection coating for iron and steel. Common industrial uses for cadmium today are in batteries, alloys, coatings (electroplating), solar cells, plastic stabilizers, and pigments. Cadmium is also used in nuclear reactors where it acts as a neutron absorber. While lithium ion batteries have made significant gains in popularity for lightweight electronic devices, new market opportunities for industrial applications of Ni-Cd batteries will continue to fuel cadmium use. Increased investment in solar power will also drive cadmium use in the future. China, South Korea, and Japan are the leading producers of cadmium in the world, followed by North America.
Cadmium and its compounds are highly toxic and exposure to this metal is known to cause cancer and targets the body's cardiovascular, renal, gastrointestinal, neurological, reproductive, and respiratory systems.
Who is exposed to cadmium?
Worker exposure to cadmium can occur in all industry sectors but mostly in manufacturing and construction. Workers may be exposed during smelting and refining of metals, and manufacturing batteries, plastics, coatings, and solar panels. The expanding Ni-Cd battery recycling industry is a concern for cadmium exposure. Electroplating, metal machining, welding and painting are operations associated with cadmium exposure. Workers involved in landfill operations, the recycling of electronic parts, or the recycling of plastics may be exposed to cadmium. Compost workers and waste collectors are also potentially exposed to dust which may contain cadmium. The incineration of municipal waste is another source of cadmium exposure.
Where is exposure to cadmium occurring?
Cadmium is an important metal for many types of businesses and industrial processes. Cadmium is most often used in the manufacturing sector but worker exposure can also occur in other industry sectors including construction, wholesale trade, and transportation. OSHA provides a publicly available Chemical Exposure Health Data which includes industrial hygiene sample results taken by OSHA field personnel during site visits. These data can provide a snapshot of industry sectors and business subcategories where cadmium air concentrations have been found. While the tables represent only a small fraction of the total number of companies in their respective industries, the results can provide insight into where workplace cadmium exposure is occurring in the United States.
Requirements to protect workers from cadmium exposure are addressed in specific OSHA standards covering general industry, maritime, construction, and agriculture.