Disodium Phosphate Anhydrous (CAS 7558-79-4), chemically identified as sodium phosphate dibasic, is a hygroscopic inorganic salt functioning as a versatile buffering agent, emulsifier, and texturizer in processed food manufacturing and industrial water treatment. This white crystalline powder, widely technically recognized as DSP or disodium hydrogen orthophosphate, acts to stabilize pH levels in dairy products (preventing protein coagulation in condensed milk) and serves as a sequestering agent in boiler water treatment to prevent scale. We provide bulk supply of this food (E339ii) and technical grade ingredient with competitive factory pricing to ensure formulation stability for diverse industries. Our production ensures rapid solubility and low heavy metal content, making MSDS, TDS, COA available alongside customized specifications to meet specific mesh size or purity requirements.
Disodium Phosphate Anhydrous CAS 7558-79-4
- CAS: 7558-79-4
- Synonyms: DSP, Sodium phosphate dibasic, Disodium monohydrogen phosphate, Disodium hydrogen orthophosphate, Sodium hydrogen phosphate
- Einecs: 231-448-7
- Molecular Formula: Na₂HPO₄
- Grade: Industrial grade / Food additive grade (customizable according to application)
- Package: 25 kg PP woven bag with PE inner liner 25 kg Kraft paper bag with PE inner
Product Description
Product Overview
Disodium hydrogen phosphate (also called disodium phosphate, Na₂HPO₄) is an inorganic phosphate salt widely used as a buffering agent, water softener, emulsifier and dispersant in food, water treatment, detergents and industrial processes. Its stable alkalinity and high solubility make it suitable for formulations where precise pH control and reliable performance are required.
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Physicochemical Properties
Typical values for reference; detailed COA can be provided with each batch.
| Item | Specification (typical) |
|---|---|
| Chemical name | Disodium hydrogen phosphate |
| Synonyms | Disodium phosphate, Sodium phosphate dibasic |
| CAS No. | 7558-79-4 |
| Einecs No. | 231-448-7 |
| Molecular formula | Na₂HPO₄ |
| Molecular weight | 141.96 g/mol |
| Appearance | White or colorless crystalline powder |
| Assay (as Na₂HPO₄) | ≥ 98.0–99.0% (by dry basis, grade-dependent) |
| pH (1% aqueous solution, 25 °C) | 8.9 – 9.2 (weakly alkaline) |
| Density (20 °C) | Approx. 1.5 g/cm³ |
| Bulk density | Approx. 0.8 – 0.9 g/cm³ (loose powder) |
| Solubility in water (20 °C) | ≥ 10 g / 100 mL, easily soluble in water |
| Odor | Odorless |
| Hygroscopicity | Slightly hygroscopic; absorbs moisture from air |
| Melting / decomposition point | ≈ 240–250 °C, decomposes on strong heating |
| Heavy metals | Controlled according to customer spec/grade |
| Insoluble matter | Typically ≤ 0.2% |
Applications
1. Food & Beverage Industry
- Buffering agent to stabilize pH in processed foods, dairy products and beverages.
- Emulsifier and texturizer in cheese, dairy powders and instant products.
- Anti-caking and dispersing agent in powdered and instant mixes.
2. Water Treatment & Boiler Systems
- Water softener to complex calcium and magnesium ions and reduce scale formation.
- Buffer in boiler water and circulating cooling water to maintain slightly alkaline conditions.
3. Detergents & Cleaning Chemicals
- Builder and buffering agent in household and industrial detergents.
- Helps to disperse dirt and improve cleaning efficiency in alkaline formulations.
4. Industrial & Technical Uses
- Buffer and dispersant in electroplating, ceramics and textile auxiliaries.
- Reagent in laboratories and chemical synthesis where controlled alkalinity is needed.
- Component in phosphate blends together with mono- and trisodium phosphates.
For application matching and formula optimization, please contact our technical team.
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Storage Conditions
- Store in a cool, dry and well-ventilated warehouse.
- Keep bags tightly closed to avoid moisture absorption and caking.
- Protect from water, high humidity and direct sunlight.
- Keep away from strong acids and strong oxidizing agents.
- Recommended storage temperature: +5 °C to +30 °C.
Under proper storage conditions, the product remains stable for the indicated shelf-life on the COA.
Safety Precautions
Disodium hydrogen phosphate is generally regarded as a low-hazard, low-toxicity inorganic salt when handled correctly, but basic industrial hygiene measures are still necessary.
- Avoid dust inhalation: Use local exhaust or dust collection in bulk handling; wear suitable dust mask/respirator if necessary.
- Avoid contact with eyes and skin:
- Wear safety glasses and gloves during handling.
- In case of eye contact, rinse immediately with plenty of water and seek medical advice if irritation persists.
- Do not ingest: If swallowed in larger amounts, rinse mouth and drink water; seek medical attention if discomfort occurs.
- Spillage: Sweep up spilled material carefully to minimize dust; collect in clean, dry containers for reuse or disposal.
- Fire & reactivity: Non-flammable solid; decomposes on strong heating, avoid contact with strong acids and strong oxidizers.
For detailed safety and first-aid information, always refer to the MSDS/SDS supplied with the product.
FAQ - Technical & Supply Chain
-
Q:
What is Disodium Phosphate Anhydrous CAS 7558-79-4?
A: Disodium phosphate anhydrous is the water-free disodium salt of phosphoric acid, Na2HPO4. It is a white crystalline or granular powder used as a buffer, emulsifier, nutrient and process aid in food, pharmaceutical and industrial applications. -
Q:
How does its pH compare with monosodium phosphate?
A: Disodium phosphate is moderately alkaline and gives a solution pH around 9, while monosodium phosphate is acidic. The two are often combined to form phosphate-buffer systems at a desired neutral pH. -
Q:
Why choose the anhydrous form instead of a hydrate?
A: The anhydrous form provides more active phosphate per unit weight and introduces no water of crystallization. It is useful in dry blends and processes where a higher concentration or lower added water is preferred. -
Q:
What are the main applications?
A: It is used in processed food and beverages as an emulsifying salt, pH buffer and mineral source, in pharmaceutical formulations, in water treatment, ceramics, textiles, detergents and as a laboratory buffer component. -
Q:
Is this product food grade?
A: The standard listing is industrial grade, with food-additive grade available and customizable according to application. Food applications should be confirmed with the supplier using the appropriate specification and documentation. -
Q:
Which packaging is available?
A: It is supplied in 25 kg PP woven bags with a PE inner liner or 25 kg kraft paper bags with a PE inner liner. Other packing can be arranged according to order volume. -
Q:
What specifications should be checked before ordering?
A: Confirm grade, assay, water, pH of solution, chloride, sulfate, heavy metals, arsenic, fluoride and loss on drying where relevant. Request the batch analysis, technical data and safety information before purchase. -
Q:
How should disodium phosphate anhydrous be stored?
A: Store in tightly sealed, moisture-proof packaging in a cool, dry, ventilated area away from acids and incompatible materials. The anhydrous form is hygroscopic, so avoid prolonged exposure to humid air and use dust-control measures.
Ordering & Documentation
Key information for document requests, quotations, and supply planning.
Documents
COA, TDS, SDS/MSDS and packing details are available on request.
Quotation
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Sample & Supply
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Storage & Shipping
Product-specific conditions are confirmed before order.
