Tetra sodium(1-HydroxyEthylidene) Diphosphonate HEDP·Na4

Tetra sodium(1-HydroxyEthylidene) Diphosphonate HEDP·Na4

Contact Us

CAS No. 3794-83-0(4-Na)   29329-71-3(x-Na)


Synonym: Tetra Sodium Salt of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP Na4); HEDP 4Na; HEDP Na4



Molecular formula: C2H4O7P2 Na4  



Relative molecular mass: 294



Structural formula


Performance and usage

HEDP Na4 is the sodium salt of HEDP and is an excellent inhibitor of calcium carbonate scale. HEDP Na4 is mainly used for metal corrosion inhibition in low-pressure boiler water treatment, circulating water treatment, industrial municipal cleaning water, and swimming pool sterilization.

This product is white powder solid, easily soluble in water, does not absorb moisture, is convenient for transportation, and is suitable for use in severe cold conditions. HEDP Na4 is an organic phosphonate scale and corrosion inhibitor, which can form stable complexes with iron, copper, zinc and other metal ions, and can dissolve the oxides on the metal surface. It still plays a good role in corrosion and scale inhibition at 250℃.

HEDP Na4 is widely used in electric power, chemical industry, metallurgy, chemical fertilizer and other industrial circulating cooling water systems, as well as scale and corrosion inhibition of medium and low pressure boilers, oil field water injection and oil pipelines; HEDP Na4 can be used as  Metal & non-metal cleaning agent in textile industry; peroxide stabilizer and color fixing agent in bleaching and dyeing industry, complexing agent in cyanide-free electroplating industry, and daily chemical additives.





Colorless or light yellow transparent liquid

White powder

Active ingredient (calculated as HEDP) %             



Active ingredient (calculated as HEDP·Na4) %        



Orthophosphorus content (calculated as PO43-) %              



Fe (as Fe2+) content mg/L    ≤             



Loss on drying % ≤






pH (1% aqueous solution)



 Packaging and storage

Liquid are packed in plastic barrels, 30KG or 250KG per barrel; solids are packed in plastic woven bags lined with polyethylene bags, with net weight of 25KG per bag, can also be custom-made according to user needs. Stored in a cool and ventilated indoor place, moisture-proof, valid for twelve months.


This product is alkaline, pay attention to labor protection during operation, avoid contact with skin, eyes, etc., rinse with plenty of water after contact.

Contact us