Etidronic Acid (EA)

Etidronic acid is a bisphosphonate used in detergents, water treatment, cosmetics and pharmaceutical treatment. Etidronic acid is a chelating agent and may be added to bind or, to some extent, counter the effects of substances, such as calcium, iron or other metal ions, which may be discharged as a component of grey wastewater and could conceivably contaminate groundwater supplies. As a phosphonate it has corrosion inhibiting properties on unnalloyed steel. Etidronic acid also acts to retard rancidification and oxidation of fatty acids. HEDP and its salts are added to detergents and other cleaning agents to prevent the effects of hard water. It is also used in peroxide bleaching to prevent degradation of peroxides by transition metals.Etidronic acid is listed as an ingredient of several cosmetic formulations where it is used for suppressing radical formation, emulsion stabilser and viscosity control.