HEDP 60% Antiscalant Water Treatment Scale Inhibitor

HEDP 60% Antiscalant, chemically known as 1-Hydroxyethylidene-1,1-Diphosphonic Acid, is a high-performance phosphonate-based water treatment chemical used for scale inhibition, metal-ion sequestration, water stabilization, and corrosion-control support in industrial water systems.

The product is supplied as a clear colorless to pale yellow transparent liquid containing a minimum of 60% active HEDP. It is highly soluble in water and is widely used in reverse osmosis pretreatment systems, cooling towers, boiler-water treatment programs, circulating-water systems, heat exchangers, desalination plants, industrial process-water systems, cleaning formulations, and other applications where mineral scale control is required.

HEDP has strong complexing ability toward metal ions such as calcium, magnesium, iron, copper, and zinc. By interacting with these ions and interfering with crystal formation and growth, HEDP helps reduce the formation and deposition of mineral scale on membranes, pipelines, heat-transfer surfaces, process equipment, and water-treatment systems.

Its phosphonate chemistry makes it suitable for a wide range of industrial water-treatment formulations and operating conditions.

Product Information

Product Name: HEDP 60% Antiscalant
Chemical Name: 1-Hydroxyethylidene-1,1-Diphosphonic Acid
Alternative Name: Hydroxyethylidene Diphosphonic Acid
Abbreviation: HEDP / HEDPA
CAS No.: 2809-21-4
EC No.: 220-552-8
Molecular Formula: C₂H₈O₇P₂
Molecular Weight: 206.02 g/mol
Grade: Industrial Grade
Physical Form: Aqueous Liquid
Appearance: Clear Colorless to Pale Yellow Transparent Liquid
Active Content: ≥60.0%
Water Solubility: Completely Soluble
Standard Packaging: 250 kg HDPE Drum
Alternative Packaging: 1250 kg IBC, where available

Key Features

• HEDP active content ≥60%
• CAS 2809-21-4
• Industrial Grade
• Phosphonate-based scale inhibitor
• Strong metal-ion complexing ability
• Excellent water solubility
• Helps reduce mineral scale formation
• Supports industrial water stabilization
• Suitable for formulated antiscalant systems
• Suitable for RO pretreatment
• Suitable for cooling-water systems
• Suitable for boiler-water treatment programs
• Suitable for industrial circulating-water systems
• Suitable for heat exchangers
• Suitable for desalination applications
• Suitable for industrial cleaning formulations
• Supplied in chemically compatible HDPE packaging

Technical Data Sheet

Scale Inhibition Mechanism

HEDP works through several complementary mechanisms to control mineral scale formation.

It can interact with dissolved metal ions and interfere with the normal formation and growth of mineral crystals.

Its performance may include:

• Metal-ion complexation
• Crystal-growth inhibition
• Crystal distortion
• Threshold scale inhibition
• Reduction of mineral precipitation
• Deposit-control support
• Water stabilization
• Mineral-dispersion support

In industrial water systems, dissolved calcium, magnesium, and other mineral ions can form deposits when water becomes supersaturated.

HEDP helps disrupt this process, reducing the tendency of hard crystalline scale to form on process surfaces.

Reverse Osmosis Applications

HEDP-based antiscalant chemistry may be used in suitable reverse osmosis pretreatment programs to reduce the risk of mineral scale formation on membrane surfaces.

Potential scale types include:

• Calcium carbonate
• Calcium sulfate
• Barium sulfate
• Strontium sulfate
• Selected metal salts

The actual effectiveness depends on the complete treatment formulation and feed-water chemistry.

Important factors include:

• Calcium hardness
• Magnesium hardness
• Alkalinity
• Sulfate
• Silica
• Barium
• Strontium
• Iron
• pH
• Temperature
• RO recovery rate
• Concentration factor
• Membrane configuration

The correct dosage should be selected based on water analysis and system-specific calculations.

Cooling Tower Water Treatment

HEDP is widely used in industrial cooling-water programs to help control scale and support corrosion-control formulations.

Suitable systems may include:

• Open recirculating cooling towers
• Closed-loop cooling systems
• Condensers
• Heat exchangers
• Cooling-water pipelines
• Process cooling systems

HEDP can assist with:

• Calcium-scale control
• Metal-ion sequestration
• Mineral-deposit control
• Water stabilization
• Heat-transfer surface protection
• Deposit-control formulations

It may be combined with other phosphonates, polymers, dispersants, corrosion inhibitors, and treatment chemicals depending on the application.

Boiler Water Treatment

HEDP may be used in selected boiler-water treatment formulations where scale-control and metal-ion management are required.

Potential functions include:

• Scale inhibition
• Deposit-control support
• Metal-ion sequestration
• Feed-water conditioning
• Boiler-water formulation support

The suitability of HEDP depends on:

• Boiler pressure
• Boiler temperature
• Feed-water quality
• System metallurgy
• Cycles of concentration
• Other treatment chemicals

A qualified water-treatment program should determine the appropriate dosage and compatibility.

Industrial Circulating Water

HEDP is suitable for a wide variety of industrial circulating-water systems.

Typical applications include:

• Process-water circuits
• Utility-water systems
• Cooling-water systems
• Industrial closed loops
• Heat-transfer systems
• Production-water circuits

Its ability to bind metal ions and interfere with mineral crystallization makes it useful as a component in water-treatment programs designed to minimize scaling and deposits.

Desalination Systems

HEDP-based antiscalant chemistry may be incorporated into suitable desalination pretreatment systems.

It can help control mineral scale where concentrated salts may otherwise precipitate during membrane treatment.

Important application factors include:

• Source-water chemistry
• Calcium concentration
• Magnesium concentration
• Sulfate
• Alkalinity
• Silica
• pH
• Temperature
• Membrane recovery
• Concentration factor

System-specific testing or scale calculations should be performed before use.

Metal-Ion Sequestration

HEDP demonstrates strong complexing ability toward several metal ions.

It can interact with:

• Calcium
• Magnesium
• Iron
• Copper
• Zinc

This makes it useful in industrial formulations where metal-ion control can help reduce precipitation, deposits, discoloration, or process interference.

Heat Exchangers

Scale formation on heat-transfer surfaces can reduce heat-transfer efficiency and increase energy consumption.

HEDP may be used as part of an industrial treatment program to help reduce mineral deposits on:

• Plate heat exchangers
• Shell-and-tube heat exchangers
• Condensers
• Evaporators
• Cooling surfaces
• Industrial process equipment

The treatment program should be based on water chemistry and operating temperature.

Industrial Cleaning

HEDP may be used in industrial cleaning formulations where sequestration and scale-control properties are required.

Potential uses include:

• Equipment-cleaning formulations
• Descaling-support formulations
• Metal-cleaning formulations
• Process-cleaning products
• CIP-related industrial formulations where compatible

HEDP can help bind dissolved metal ions and reduce precipitation during cleaning.

Detergent & Cleaning Formulations

HEDP can function as a chelating or sequestration component in selected cleaning formulations.

It may be incorporated into:

• Industrial detergents
• Institutional cleaners
• Process cleaners
• Hard-surface cleaning formulations
• Metal-cleaning products
• Bleaching-support formulations

Its use helps manage hardness ions and trace metals that may interfere with cleaning performance.

Textile Processing

HEDP may be used in selected textile-process formulations to help control metal ions and mineral deposits.

Potential applications include:

• Textile washing
• Bleaching-process support
• Dyeing-process water treatment
• Process-water conditioning
• Equipment scale control

Product compatibility should be evaluated for the specific textile chemistry involved.

Pulp & Paper Industry

HEDP may be used in selected pulp and paper applications where mineral scale and metal-ion control are required.

Possible uses include:

• Process-water stabilization
• Heat-exchanger protection
• Deposit control
• Equipment cleaning
• Mineral-scale inhibition
• Metal-ion sequestration

Oilfield & Industrial Process Water

HEDP may also be used in selected oilfield and industrial-process-water systems.

Potential applications include:

• Scale inhibition
• Water stabilization
• Metal-ion control
• Process-equipment protection
• Industrial water circulation
• Injection-water treatment formulations

The required dosage and formulation should be determined by water analysis and application testing.

Recommended Dosage

There is no universal dosage suitable for every HEDP application.

The required dosage depends on:

• Water hardness
• Calcium concentration
• Magnesium concentration
• Alkalinity
• Sulfate
• Silica
• Iron
• pH
• Temperature
• Flow rate
• System pressure
• Concentration cycles
• Membrane recovery rate
• Scale saturation index
• Contact time
• Other treatment chemicals

A water analysis and system-specific treatment calculation should be performed before full-scale use.

Important Product Positioning

This product is:

HEDP 60% Industrial Grade phosphonate scale inhibitor and antiscalant raw material.

It may be used as a primary active ingredient in many industrial water-treatment formulations.

However, HEDP 60% should not automatically be described as a proprietary multi-component RO antiscalant if the product being supplied consists only of HEDP solution.

A formulated commercial RO antiscalant may contain:

• HEDP
• Other phosphonates
• Polymeric dispersants
• Carboxylate polymers
• Specialty scale-control agents
• Stabilizers
• Other formulation components

Those products should normally have their own separate specification.

Packaging

Standard Packaging

250 kg HDPE Drum

HDPE packaging provides suitable chemical compatibility for acidic phosphonate solution when properly specified.

Bulk Packaging

Where available:

1250 kg IBC

Other compatible bulk packaging may be available according to order volume and transportation requirements.

Storage

Store HEDP 60%:

• In a cool and dry area
• In a well-ventilated chemical warehouse
• In suitable corrosion-resistant containers
• With containers tightly closed
• Away from excessive heat
• Protected from direct sunlight
• Protected from contamination
• Away from incompatible chemicals
• With suitable secondary containment

Use chemically compatible:

• Tanks
• Pumps
• Valves
• Pipes
• Hoses
• Seals
• Gaskets

Avoid prolonged storage in unsuitable reactive metal containers.

Handling

HEDP 60% is acidic and should be handled using appropriate industrial chemical procedures.

Avoid:

• Skin contact
• Eye contact
• Inhalation of mist
• Ingestion
• Uncontrolled release
• Splashing
• Contact with incompatible materials

Suitable personal protective equipment may include:

• Chemical-resistant gloves
• Safety goggles
• Face shield where splash risk exists
• Chemical-resistant protective clothing
• Appropriate footwear

Work areas should have suitable:

• Ventilation
• Eyewash facilities
• Emergency safety showers
• Spill containment
• Chemical handling procedures

Always follow the current product-specific SDS.

Transport Information

Typical transport reference:

UN Number: UN 3265
Transport Description: Corrosive Liquid, Acidic, Organic, N.O.S.
Hazard Class: 8
Packing Group: II

The exact shipping classification should always be checked against the current SDS and relevant transport rules for the supplied concentration and destination.

Applicable regulations may include:

• ADR
• RID
• IMDG
• IATA
• National road-transport regulations
• Port and carrier requirements

Quality Control

Commercial HEDP 60% should be inspected against the approved product specification before shipment.

Typical quality-control parameters include:

• Appearance
• HEDP active content
• Phosphorous acid
• Phosphoric acid
• Chloride
• pH
• Density
• Calcium chelation value
• Iron content

Each shipment should be supported by a batch-specific Certificate of Analysis where required.

Certificate of Analysis Specification

The specification column may be included in the product listing or TDS.

Actual COA test results should only be entered after the batch has been tested.

Technical Data Summary

Product: HEDP 60% Antiscalant
Chemical Name: 1-Hydroxyethylidene-1,1-Diphosphonic Acid
CAS: 2809-21-4
EC: 220-552-8
Formula: C₂H₈O₇P₂
Molecular Weight: 206.02 g/mol
Grade: Industrial Grade
Appearance: Clear Colorless to Pale Yellow Transparent Liquid
Active HEDP: ≥60.0%
Phosphorous Acid: ≤2.0%
Phosphoric Acid: ≤0.8%
Chloride: ≤0.02%
pH, 1% Solution: 1.5–2.0
Density at 20°C: ≥1.40 g/cm³
Calcium Chelation Value: ≥500 mg/g
Iron as Fe: ≤20 mg/L
Solubility: Completely Soluble in Water
Packaging: 250 kg HDPE Drum
Bulk Packaging: 1250 kg IBC
Primary Function: Scale Inhibition
Secondary Function: Metal-Ion Sequestration / Water Stabilization
Primary Applications: RO / Cooling Towers / Boilers / Industrial Circulating Water

Documentation

Available documentation may include:

• Technical Data Sheet — TDS
• Safety Data Sheet — SDS
• Batch-Specific Certificate of Analysis — COA
• Commercial Invoice
• Packing List
• Certificate of Origin
• Dangerous Goods Documentation where applicable

Any additional certification should only be claimed if valid documentation exists for the supplied product.

Grade & Certification Limitation

This product is offered as:

HEDP 60% Industrial Grade

It should not automatically be represented as:

• Food Grade
• Pharmaceutical Grade
• Drinking Water Grade
• NSF Certified
• AWWA Approved
• Cosmetic Grade
• Medical Grade
• Membrane-Manufacturer Approved

unless the actual supplied grade has the appropriate specification and supporting certification.

Product Summary

HEDP 60% Antiscalant, CAS 2809-21-4, is a phosphonate-based industrial water-treatment chemical supplied as a clear colorless to pale yellow transparent liquid with ≥60% active HEDP.

The product provides strong metal-ion complexing and scale-inhibition properties and can be used as an active component in industrial treatment programs for reverse osmosis systems, cooling towers, boilers, circulating-water systems, desalination systems, heat exchangers, industrial cleaning, process water, and other scale-control applications.

The commercial specification includes ≥60.0% active HEDP, ≤2.0% phosphorous acid, ≤0.8% phosphoric acid, ≤0.02% chloride, pH 1.5–2.0, density ≥1.40 g/cm³, calcium chelation value ≥500 mg/g, and iron ≤20 mg/L.

Standard packaging is 250 kg HDPE drums, with 1250 kg IBC packaging available where required.

For best performance, the treatment dosage should be determined according to actual water chemistry, system operating conditions, scale-forming potential, and technical treatment requirements.