EDTA Disodium Salt 99% vs EDTA Edetic Acid 99.0% – What’s the Difference and Which One Should You Use?

May 26, 2026 • chaleting agent • edta

When shopping for chelating agents in the UK chemical market, two products often cause confusion: EDTA Disodium Salt 99% and EDTA Edetic Acid 99.0%. While both are forms of EDTA and share similar chemical foundations, they behave very differently in practical applications. Understanding these differences is essential for laboratories, industrial users, water treatment specialists, cosmetic formulators, and cleaning product manufacturers.

If you are searching for where to buy EDTA Disodium Salt UK online or where to buy EDTA Edetic Acid UK online, understanding their chemical structure, pH behaviour, solubility, and intended uses can help you avoid formulation problems and improve product performance.

At HD Chemicals UK Supplier , both grades are available for professional and industrial applications across the United Kingdom.

What Is EDTA?

EDTA stands for Ethylenediaminetetraacetic Acid, one of the most widely used chelating agents in chemistry and industry. Chelating agents bind metal ions such as:

Calcium
Magnesium
Iron
Copper
Zinc
Lead

This ability makes EDTA extremely useful in:

Water treatment
Cleaning products
Cosmetics
Pharmaceuticals
Agriculture
Laboratory analysis
Food processing
Textile manufacturing

The main purpose of EDTA is to remove or control unwanted metal ions that may interfere with chemical reactions, cause instability, reduce cleaning efficiency, or damage products.

Understanding the Two Main Forms

Although they are related chemically, EDTA Edetic Acid and EDTA Disodium Salt are not interchangeable in every situation.

EDTA Edetic Acid 99.0%

EDTA Edetic Acid is the acid form of EDTA.

Basic Characteristics

Property	EDTA Edetic Acid
Chemical Name	Ethylenediaminetetraacetic Acid
Purity	99.0%
Appearance	White crystalline powder
pH	Acidic
Solubility in Water	Low
Chelating Strength	Very strong
CAS Number	60-00-4

Key Features

Lower water solubility
Acidic behaviour
Requires neutralisation in some formulations
Preferred for controlled pH applications
Often used in laboratories and specialised industrial systems

EDTA Disodium Salt 99%

EDTA Disodium Salt is a partially neutralised sodium salt version of EDTA.

Basic Characteristics

Property	EDTA Disodium Salt
Chemical Name	Disodium EDTA
Purity	99%
Appearance	White powder
pH	Mildly acidic to neutral
Solubility in Water	High
Chelating Strength	Strong
CAS Number	6381-92-6

Key Features

Dissolves much more easily in water
Easier to formulate into liquid systems
Common in cosmetics and cleaning products
Better suited for room-temperature mixing
More user-friendly for industrial production

The Core Chemical Difference

The difference comes down to neutralisation.

EDTA Acid Structure

$H_4EDTA$

EDTA Edetic Acid contains four acidic hydrogen atoms.

Disodium EDTA Structure

$Na_2H_2EDTA$

In Disodium EDTA, two of those acidic hydrogens have been replaced with sodium ions.

This structural change dramatically alters:

Water solubility
pH
Handling
Dissolution speed
Formulation compatibility

Solubility Differences

One of the biggest practical differences is water solubility.

EDTA Edetic Acid Solubility

EDTA acid dissolves poorly in cold water.

Typical mixing often requires:

Heating
Strong agitation
pH adjustment using sodium hydroxide

Example

10 grams of EDTA acid added to 1 litre of cold water may remain partially undissolved without pH correction.

This can complicate manufacturing processes.

EDTA Disodium Salt Solubility

Disodium EDTA dissolves far more easily.

Example

10 grams of EDTA Disodium Salt in 1 litre of warm water generally dissolves quickly with minimal agitation.

This makes it ideal for:

Cosmetic production
Cleaning formulations
Industrial liquid concentrates
Water treatment chemicals

pH Behaviour Explained

The acid form and sodium salt affect pH differently.

EDTA Edetic Acid

The acid form lowers solution pH significantly.

Example

Adding 5 grams per litre to distilled water may create a strongly acidic solution.

This can be beneficial when acidic conditions are desired.

EDTA Disodium Salt

Disodium EDTA is much less acidic.

It allows formulators to maintain a more stable pH range in products like:

Shampoo
Soap
Surface cleaners
Industrial detergents

Chelation Performance

Both products are excellent metal chelators.

Metal Binding Reaction

$M^{2+}+EDTA^{4-}\rightarrow [MEDTA]^{2-}$

Where:

$M^{2+}$ represents a metal ion such as calcium or magnesium
EDTA traps the metal into a stable complex

Which Form Chelates Better?

Technically, both forms become active chelators after dissolving.

Feature	EDTA Acid	Disodium EDTA
Dissolution Speed	Slower	Faster
Ease of Use	More difficult	Easier
Industrial Compatibility	Moderate	Excellent
pH Adjustment Needed	Often	Rarely
Cosmetic Use	Less common	Very common

In most liquid formulations, Disodium EDTA is preferred because it is easier to handle.

Applications of EDTA Disodium Salt 99%

1. Cosmetics and Personal Care

Disodium EDTA is heavily used in:

Shampoo
Conditioner
Body wash
Face cleanser
Lotion
Liquid soap

Why?

Metal ions in tap water can destabilise cosmetic formulations.

Disodium EDTA prevents:

Product discoloration
Texture changes
Reduced foaming
Oxidation

Typical Usage

0.05% to 0.2%

Example

1 gram added to 1 litre of shampoo base.

2. Cleaning Products

Used in:

Bathroom cleaners
Industrial detergents
Scale removers
Degreasers

It improves cleaning by binding calcium and magnesium from hard water.

Example Formula

5 grams Disodium EDTA
50 grams surfactant
945 ml water

Produces a hard-water-resistant cleaner.

3. Water Treatment

Disodium EDTA controls hardness ions.

Useful in:

Cooling towers
Boilers
Pipe systems

4. Textile Industry

Helps prevent unwanted metal contamination during dyeing.

5. Agriculture

Used in micronutrient fertilisers.

Example

Iron EDTA fertilisers improve iron uptake in plants.

Applications of EDTA Edetic Acid 99.0%

1. Laboratory Analysis

Widely used in titration chemistry.

Example

Water hardness testing commonly uses EDTA acid.

2. Pharmaceutical Processing

The acid form is useful where exact pH control matters.

3. Industrial Descaling

Strong metal binding helps remove deposits.

4. Chemical Manufacturing

Used as a raw intermediate for producing EDTA salts.

5. Electroplating

Controls unwanted metal reactions during plating operations.

Mixing Instructions

How to Dissolve EDTA Disodium Salt

Standard Procedure

For 1 litre solution:

Add 800 ml warm water
Slowly add 20 grams Disodium EDTA
Stir continuously
Top up to 1 litre

Usually dissolves easily at room temperature.

How to Dissolve EDTA Edetic Acid

Standard Procedure

For 1 litre solution:

Add 800 ml warm water
Add 20 grams EDTA acid
Slowly add sodium hydroxide solution
Continue stirring until clear
Top up to 1 litre

Without pH adjustment, dissolution may remain incomplete.

Which One Is Better for Cleaning Products?

Winner: EDTA Disodium Salt

Reasons:

Easier mixing
Better water compatibility
Lower formulation complexity
Faster production

For industrial and domestic cleaning applications, most manufacturers choose:

where to buy EDTA Disodium Salt UK online

Which One Is Better for Laboratory Use?

Winner: EDTA Edetic Acid

Reasons:

Precise chemistry
Greater control over reactions
Useful for titration standards

Laboratories and technical users often prefer:

where to buy EDTA Edetic Acid UK online

Which One Is Better for Cosmetics?

Winner: EDTA Disodium Salt

Most cosmetic manufacturers prefer the disodium form due to:

Better compatibility
Faster dissolution
Easier pH balancing

Commonly used in:

Shampoo
Liquid soap
Facial cleansers
Skincare products

Available here:

where to buy EDTA Disodium Salt UK online

Stability Comparison

Property	EDTA Acid	Disodium EDTA
Storage Stability	Excellent	Excellent
Moisture Sensitivity	Low	Moderate
Heat Stability	Excellent	Excellent
Shelf Life	Long	Long

Store both in:

Cool dry environment
Sealed containers
Away from strong oxidisers

Safety Considerations

Both products should be handled professionally.

PPE Recommendations

Gloves
Safety goggles
Dust mask
Ventilation

Always follow UK chemical handling regulations and safety data sheet recommendations.

Environmental Considerations

EDTA compounds are persistent chelators and can remain in the environment.

Proper disposal procedures should always be followed according to UK regulations.

Avoid direct discharge into waterways without treatment.

Cost Comparison

Typically:

Product	Relative Cost
EDTA Acid	Slightly lower
Disodium EDTA	Slightly higher

However, Disodium EDTA may reduce manufacturing costs due to easier handling and reduced processing time.

Industrial Examples

Example 1 – Hard Water Cleaner

Formula

2 litres water
20 grams Disodium EDTA
100 grams surfactant

Result

Improved cleaning efficiency in hard water areas.

Example 2 – Laboratory Chelation Solution

Formula

1 litre water
50 grams EDTA acid
Sodium hydroxide to adjust pH

Result

Suitable for analytical chemistry applications.

Common Mistakes When Choosing EDTA

Mistake 1 – Assuming They Are Identical

They are chemically related but function differently in formulations.

Mistake 2 – Using EDTA Acid in Cosmetic Products Without Neutralisation

This can destabilise pH-sensitive ingredients.

Mistake 3 – Expecting EDTA Acid to Dissolve Quickly

It often requires pH adjustment.

How to Decide Which Product You Need

Choose EDTA Disodium Salt If You Need:

Fast dissolution
Cosmetic compatibility
Cleaning formulations
Water treatment applications
General industrial use

Search:

where to buy EDTA Disodium Salt UK online

Available from:

HD Chemicals UK Supplier

Choose EDTA Edetic Acid If You Need:

Laboratory precision
Acidic formulations
Controlled pH chemistry
Chemical synthesis

Search:

where to buy EDTA Edetic Acid UK online

Available from:

HD Chemicals UK Supplier

Final Thoughts

Although EDTA Disodium Salt 99% and EDTA Edetic Acid 99.0% belong to the same chemical family, they are designed for different purposes. The acid form provides strong chemical control and laboratory usefulness, while the disodium salt offers easier handling and superior compatibility for industrial and cosmetic formulations.

For most practical liquid applications, Disodium EDTA is the easier and more convenient option. However, EDTA acid remains important where precise chemical control is necessary.

Choosing the correct version can significantly improve product stability, production efficiency, and overall performance.

For reliable UK chemical supply, industrial quantities, and laboratory-grade materials, visit:

HD Chemicals Main Website

FAQs

1. Is EDTA Disodium Salt the same as EDTA acid?

No. Disodium EDTA is a partially neutralised sodium salt version of EDTA acid.

2. Which dissolves better in water?

EDTA Disodium Salt dissolves much more easily.

3. Which is used in cosmetics?

Disodium EDTA is commonly used in shampoos, soaps, and skincare products.

4. Why is EDTA used in cleaning products?

It removes hardness ions like calcium and magnesium that reduce cleaning efficiency.

5. Can EDTA acid be used directly in water?

Yes, but dissolution may require pH adjustment and heating.

6. Which form is better for laboratory titrations?

EDTA Edetic Acid is often preferred for analytical chemistry applications.

7. Is Disodium EDTA acidic?

It is mildly acidic but much less acidic than EDTA acid.

8. What metals does EDTA bind?

Common metals include calcium, magnesium, iron, copper, zinc, and lead.

9. Is EDTA safe to handle?

Yes, when using proper PPE and industrial handling procedures.

10. Where can I buy EDTA chemicals in the UK?

You can purchase both products directly from HD Chemicals:

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