The Toxicity of Niobium Salts

The acute and sub-acute toxicity of potassium niobate and niobium pentachloride has been investigated. Single intravenous doses of 20 mg Nb/kg or less to rats, rabbits, and dogs were not fatal. The LD50 (seven-day) value for mice and rats given a single intraperitoneal injection of potassium niobate was 13 and 92 mg Nb/kg, respectively. The oral LDso (seven-day) value for the rat was 725 mg Nb/kg. Renal injury was observed in all species following parenteral injection at doses ranging from 20 to 50 mg Nb/kg. Repeated intraperitoneal injections of nobium pentachloride or potassium niobate of 30 mg Nb/kg resulted in renal injury and death. Dietary levels as high as 1% of either compound were ingested by rats, for a seven-week period, without effect. The nephrotoxic action of niobium was not observed when the niobium salt was complexed with ascorbic acid prior to injection.