Dimercaprol (2, 3-dimercapto-1-propanol) or British anti-Lewisite (BAL), is a colorless or almost colorless liquid chelating agent having a disagreeable, mercaptan-like odor. Dimercaprol was developed at Oxford University during World War II as a means of treating and reversing poisoning from Lewisite, an arsenical gas used in chemical warfare (and thus initially called British anti-Lewisite [BAL]). The sulfhydryl groups of dimercaprol form complexes with certain heavy metals thus preventing or reversing the metallic binding of sulfhydryl-containing enzymes. Parenterally administered dimercaprol is used to treat arsenic, gold, copper and mercury poisoning. It is indicated in acute lead poisoning when used concomitantly with edetate clcium disodium. Dimercaprol is occasionally used in the initial treatment of severe, symptomatic Wilson disease, but generally for a short time only.