EDTMP Sodium


EDTMP Sodium is nitrogenous organic polyphosphoric acid, a part of a cathodic corrosion inhibitor. Its corrosion inhibition is 3-5 times better than that of inorganic polyphosphate. EDTMP Sodium can be fully dissolved in water. It is innocuous and no pollution to the environment.

Ethylenediamine tetramethylene phosphonic acid sodium also has good chemical stability and thermal tolerance. It shows excellent scale inhibition ability under a temperature of 200°C.

It can dissociate into 8 positive-negative ions, thus can chelate with many metal ions to form polymer reticulation complex, to destroy the normal crystallization of calcium scale. EDTMP sodium shows better antiscale effects on calcium sulfate and barium sulfate.

CAS No.: 1429-50-1

Molecular Formula: C6H12O12N2P4Na8

Molecular Weight: 612.13

Structural Formula:

EDTMP Sodium


AppearanceClear yellow to umber transparent liquid
Active component (EDTMPS), %30 Min.
Organic phosphonic acid (as PO43-), %10.0 Min.
Phosphorous acid (as PO33-), %5.0 Max.
Phosphoric acid (as PO43-), %1.0 Max.
Chloride (Cl), %3.0 Max.
pH (1% solution)9.5~10.5
Density (20℃) g/cm31.25 Min.


EDTMP sodium can be used as a corrosion inhibitor in circulating cool water system and boiler water. It is a chelating agent in the non-cyanogen electroplating industry and a water-softening agent in the printing & dyeing industry.

When used alone, 2-10 mg/L is preferred. When built with HPMA by ratio ETDMP:HPMA=1:3, EDTMP sodium can be used for the low-pressure boiler. It can also be built with BTA, PAAS and zinc salt.

Package and Storage:

200L plastic drum, IBC(1000L), as customers’ requirement. Storage for ten months in a shady room and dry place.