Cadmium is a bluish-white, malleable, and ductile metallic element that is toxic and bivalent, often used in protective coatings, plating, and specialized metal alloys.
Cadmium (chemical symbol Cd) is a soft, silvery-white transition metal known for its corrosion resistance, malleability, and ability to bond well with other metals. It is bivalent, typically forming compounds with a +2 oxidation state. Although found naturally in the Earth’s crust, cadmium is most often produced as a byproduct of zinc, lead, or copper refining. Its durability and resistance to wear make it valuable for industrial and electrical applications where longevity and protection are essential.
In the wire and cable industry, cadmium is used in alloying processes, such as in cadmium bronze or cadmium copper, to enhance mechanical strength without greatly sacrificing conductivity. It is also used in specialized coatings that resist corrosion and reduce friction. However, because cadmium is toxic, strict environmental and occupational controls govern its use, leading to the adoption of safer substitutes in many applications.
Cadmium use is heavily regulated due to its toxicity and environmental persistence. Oversight is provided by organizations such as OSHA (Occupational Safety and Health Administration), the EPA (Environmental Protection Agency), and the RoHS Directive in the European Union. ASTM and IEEE also reference cadmium in alloy classifications and electrical standards.
Discovered in 1817 by German chemist Friedrich Stromeyer while studying zinc compounds, cadmium quickly gained industrial importance for its corrosion resistance. It became widely used in plating, batteries, and metal alloys through the 19th and 20th centuries. Modern regulations have limited its use, but cadmium remains significant in niche applications requiring specific electrical or mechanical performance that substitutes cannot match.