Antimony

Antimony (Sb; CASRN 7440-36-0) is a silvery semimetal element with chemical properties similar to lead, arsenic, and bismuth. In nature, it is found associated with sulfur as stibnite. Antimony is used in white metal, a group of alloys having relatively low melting points. White metal usually contains tin, lead, or antimony as the chief component. The introduction of antimony into the human environment is overwhelmingly the result of human activity; approximately half of the antimony used in the United States is recovered from lead-based battery scrap. Most information regarding antimony toxicity has been obtained from industrial exposures. Occupational exposures usually occur through inhalation of dusts containing antimony compounds. Antimony is absorbed slowly through the oral route, and many antimony compounds are gastrointestinal irritants. The toxicity of Sb is a function of the water solubility and the oxidation state (+3 or −3) of the Sb species in question. The American Conference of Governmental Industrial Hygienists classifies antimony as a suspected human carcinogen.