HEDP•Na4 technical indicators

Here are the technical indicators (specifications) for HEDP•Na₄ (Tetrasodium Etidronate), a widely used scale and corrosion inhibitor in water treatment, oilfields, and industrial applications:

HEDP•Na₄ (Tetrasodium Etidronate) Technical Specifications

Parameter Standard Specifications Testing Method

Chemical Name Tetrasodium 1-Hydroxyethylidene-1,1-Diphosphonate —

CAS No. 3794-83-0 —

Molecular Formula C₂H₆O₇P₂Na₄ —

Appearance Colorless to light yellow transparent liquid Visual

Active Content ≥ 28.0% (as HEDP•Na₄) Titration (Na⁺)

pH (1% solution) 10.0–12.0 pH meter

Density (20°C) 1.30–1.40 g/cm³ Hydrometer

Phosphorus Content (as PO₄³⁻) ≥ 18.0% ICP/OES

Iron (Fe) Content ≤ 0.001% (10 ppm) AAS/ICP

Chloride (Cl⁻) ≤ 0.1% Titration

Solubility Fully soluble in water —

Thermal Stability Stable up to 100°C Heat aging test

Key Performance Features

High Chelating Ability – Strong binding with Ca²⁺, Mg²⁺, Fe²⁺/Fe³⁺, preventing scale formation.

Excellent Scale Inhibition – Effective against CaCO₃, CaSO₄, BaSO₄ scales.

Corrosion Inhibition – Forms a protective film on metal surfaces (carbon steel, copper).

Chemical Stability – Resists hydrolysis and chlorine attack (better than HEDP acid form).

Compatibility – Works well with polymers, zinc salts, and oxidizing biocides.

Comparison: HEDP•Na₄ vs. HEDP (Acid Form)

Property HEDP•Na₄ HEDP (Acid Form)

pH 10–12 (Alkaline) 1–2 (Acidic)

Solubility Higher in water Lower (requires neutralization)

Handling Safety Less corrosive Highly corrosive (needs PPE)

Storage Stable long-term May crystallize at low temps

Typical Applications

Cooling Water Treatment (5–30 ppm)

Oilfield Scale Inhibition (10–50 ppm in produced/injection water)

Textile & Detergent Industry (as a chelating agent)

Metal Surface Treatment (electroplating, pickling)

Packaging & Storage

25 kg, 200 kg plastic drums or 1000 kg IBC tanks.

Store in a cool, dry place (avoid freezing).

Shelf life: 12 months (unopened).

Safety & Environmental Data

Non-toxic, biodegradable (partial).

LD50 (oral, rat): >2000 mg/kg (low toxicity).

Compliance: Meets REACH, EPA, and OSPAR regulations.

Note: For specific formulations (e.g., with zinc or polymers), conduct compatibility tests before field application.