Water Quality
Standards
Summary information extracted from: Guidelines for drinking-water quality, 2nd ed. Addendum to Vol. 1.- Recommendations. - Geneva, World Health Organization, 1998. pp. 14-15.
Human exposure to EDTA arises directly from its use in food additives, medicines, and personal care and hygiene products. Exposure to EDTA from drinking-water is probably very small in comparison with that from other sources.
Once EDTA is present in the aquatic environment, its speciation will depend on the water quality and the presence of trace metals with which it can combine. The removal of EDTA from communal wastewater by biodegradation in sewage purification plants is very limited.
In 1973, JECFA established an ADI of 2.5 mg/kg of body weight for calcium disodium edetate as a food additive (1.9 mg/kg of body weight as the free acid). JECFA further evaluated the toxicological studies available on sodium iron EDTA in 1993; no further important information regarding the toxicity of EDTA and its calcium and sodium salts could be added to the 1973 evaluation. Concern has been expressed over the ability of EDTA to complex, and therefore reduce the availability of, zinc. However, this is of significance only at elevated doses substantially in excess of those encountered in the environment.
A guideline value for EDTA in drinking-water can be derived by allocating 1% of the ADI (1.9 mg/kg of body weight as the free acid) to drinking-water (because of the potential for significant exposure from food owing to use of EDTA as a food additive). Assuming a 60-kg adult ingesting 2 litres of drinking-water per day, the guideline value for EDTA (free acid) is therefore 600 µg/litre (rounded figure).
Source literature
Joint FAO/WHO Expert Committee on Food Additives. Ethylenediaminetetraacetate, disodium and calcium disodium salts. In: Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers, and thickening agents. Geneva, World Health Organization, 1974 (WHO Food Additives Series, No. 5).
Joint FAO/WHO Expert Committee on Food Additives. Sodium iron EDTA. In: Toxicological evaluation of certain food additives and contaminants. Geneva, World Health Organization, 1993 (WHO Food Additives Series, No. 32).
