A study was performed to provide data on the disposition, accumulation and toxicity of sodium iron EDTA in comparison with iron (II) sulfate in rats on administration via the diet for 31 and 61 days. Clinical signs, body weights, food consumption, food conversion efficiency, hematology, clinical chemistry and pathology of selected organs were used as criteria for disclosing possible harmful effects. Determination of iron and total iron binding capacity in blood plasma and non-heme iron analysis in liver, spleen and kidneys were used to assess the disposition and accumulation of iron originating from sodium iron EDTA or iron (II) sulfate. It was concluded that, under the conditions of the present study, iron is accumulated from the diet in liver, spleen and kidneys in a dose-dependent manner, and iron derived from FeEDTA is taken up and/or accumulated less efficiently in liver and spleen than iron from FeSO4. Moreover, feeding iron up to 11.5 and 11.2 mg/kg body weight/day, derived from FeSO4 and FeEDTA, respectively, did not result in tissue iron excess nor in any other toxicologically significant effects. © 2001 Elsevier Science Ltd. Chemicals/CAS: Coloring Agents; Edetic Acid, 60-00-4; Fe(III)-EDTA, 15275-07-7; Ferric Compounds; ferric sulfate, 10028-22-5; Iron, 7439-89-6; Nonheme Iron Proteins