The judicious use of chelating (metal binding) agents for the removal of toxic amounts of metal ions from living organisms. The metal ions are sequestered by the chelating agents and are rendered harmless or excreted. Chelating agents such as 2,3-dimercaptopropan-1-ol, ethylenediaminetetraacetic acid, desferrioxamine and D-penicillamine have been used effectively in chelation therapy for arsenic, lead, iron and copper, respectively.