Etidronate disodium

Etidronate disodium (CAS 7414-83-7), also known as HEDP disodium, is the disodium salt form of hydroxyethylidene diphosphonic acid used commercially as a chelating and sequestering agent. It binds metal ions, particularly calcium and heavy metals, to prevent scale formation, oxidative degradation, and microbial activity across industrial and formulated product applications.

In water treatment, it controls calcium carbonate and metal oxide scale in cooling towers, boilers, and process water systems. Personal care formulators incorporate it into shampoos and creams. It is used in rinse-off products to sequester trace metals that would otherwise destabilize peroxide-based systems or accelerate rancidity. Textile and leather processing operations use it to deactivate hardness ions.

This improves process consistency and color yield in dye baths and bleaching liquors. In pharmaceutical manufacturing, it functions as a stabilizing excipient in liquid formulations where oxidation must be controlled. Etidronate disodium is supplied as a white crystalline powder and as aqueous solution, with solution concentrations typically around 30–40%. Standard grades include technical and pharmaceutical specifications.

Material is available to meet USP and BP standards, with food-contact and cosmetic-grade material available to meet purity requirements for various regulated applications.