E-mail: sales001@bosschemical.com JINAN BOSS CHEM CO.,LTD
Telephone: +86-15628782329
- All
- Product Name
- Product Keyword
- Product Model
- Product Summary
- Product Description
- Multi Field Search
Views: 0 Author: Site Editor Publish Time: 2026-08-06 Origin: Site
Sodium pyrophosphate decahydrate (CAS 13472-36-1), also known as tetrasodium pyrophosphate decahydrate (TSPP decahydrate), is an inorganic compound with the chemical formula Na₄P₂O₇·10H₂O. It belongs to the pyrophosphate family and exists as a white, crystalline powder or colorless crystals that are freely soluble in water, forming an alkaline solution.
This compound falls under the broader category of condensed phosphates and is recognized as a food additive under the E-number E450(iii) in the European Union. While sharing the same core anion (P₂O₇⁴⁻) as its anhydrous counterpart (CAS 7722-88-5), the decahydrate form contains ten water molecules of crystallization, giving it distinct physical properties and handling characteristics.
The compound is produced industrially through the thermal dehydration of disodium phosphate (Na₂HPO₄) at controlled temperatures, followed by controlled crystallization to obtain the decahydrate form. It is one of the most commercially significant pyrophosphates, with annual global production exceeding hundreds of thousands of metric tons.
Understanding the physical and chemical characteristics of sodium pyrophosphate decahydrate is essential for proper handling, storage, and application across industries.
Property | Value |
Chemical Name | Tetrasodium pyrophosphate decahydrate |
Molecular Formula | Na₄P₂O₇·10H₂O |
Molecular Weight | 446.06 g/mol |
CAS Number | 13472-36-1 |
EC Number | 231-767-1 |
Appearance | White crystalline powder or colorless crystals |
Odor | Odorless |
Density | ~1.82 g/cm³ |
Bulk Density | ~650 kg/m³ |
Melting Point | ~79.5°C (decahydrate; loses water of crystallization) |
pH (1% solution) | 9.8–10.5 (alkaline) |
Water Solubility at 20°C | ~6.23 g/100 mL |
Water Solubility at 100°C | ~40.26 g/100 mL |
Loss on Drying | ≤2.0% (at 105°C for 4 hours, food grade) |
A common question among industrial buyers is whether to purchase the anhydrous or decahydrate form of tetrasodium pyrophosphate. While chemically similar—both provide the same P₂O₇⁴⁻ anion in solution—there are practical differences that affect procurement and formulation decisions.
Feature | Anhydrous TSPP (CAS 7722-88-5) | Decahydrate TSPP (CAS 13472-36-1) |
Water Content | ~0% | ~40.3% (10 H₂O) |
Molecular Weight | 265.90 g/mol | 446.06 g/mol |
Melting Point | 988°C | ~79.5°C |
Density | ~2.53 g/cm³ | ~1.82 g/cm³ |
Appearance | White powder | White crystals or crystalline powder |
Moisture Sensitivity | Hygroscopic; absorbs moisture from air | Less hygroscopic; more storage-stable |
Effective Na₄P₂O₇ per kg | ~1,000 g | ~596 g |
Dissolution Rate | Slower | Faster (pre-hydrated) |
Cost per Unit of Active | Generally lower | Higher due to water weight |
Preferred Applications | High-temperature processes, detergent manufacturing | Cold-process formulations, food applications, laboratory use |
Choose anhydrous TSPP
● when: you need maximum active content per unit weight, your process involves high temperatures (>100°C), or shipping cost is a primary concern.
Choose decahydrate TSPP
● when: you need faster dissolution in cold water, you are formulating products at ambient temperature, your process benefits from the crystalline form's flowability, or you require food-grade material for cold-process food applications.
Sodium pyrophosphate decahydrate is a versatile workhorse across multiple industrial sectors, valued primarily for its sequestering, dispersing, and buffering capabilities.
TSPP decahydrate is one of the most widely used phosphate builders in detergent formulations. Its role is multifaceted:
Water Softening
● : Chelates calcium and magnesium ions responsible for water hardness, preventing them from interfering with surfactant performance.
Soil Dispersion
● : Deflocculates and suspends particulate soils, preventing re-deposition onto fabrics or surfaces during the wash cycle.
Alkalinity Buffering
● : Maintains an optimal alkaline pH for cleaning efficiency without being excessively caustic.
Metal Ion Sequestration
● : Binds iron, copper, and manganese ions that can cause staining or catalyze bleach decomposition.
It is particularly effective in heavy-duty laundry detergents, industrial degreasers, automatic dishwashing detergents, and commercial cleaning formulations.
In industrial and municipal water systems, sodium pyrophosphate decahydrate serves as a critical scale inhibitor and corrosion control agent:
Scale Prevention
● : By sequestering calcium and magnesium ions, TSPP prevents the formation of insoluble carbonate and sulfate scales on heat exchanger surfaces, boiler tubes, and cooling tower packing.
Corrosion Inhibition
● : Forms a thin, protective film on metal surfaces that acts as a cathodic inhibitor, reducing corrosion rates in steel and copper piping systems.
Iron & Manganese Control
● : Prevents "red water" and "black water" issues in distribution systems by chelating dissolved iron and manganese.
Threshold Treatment
● : Effective at sub-stoichiometric concentrations (typically 2–10 mg/L), making it cost-efficient for large-scale water systems.
The metal finishing industry relies on TSPP decahydrate for several critical functions:
Electroplating Baths: Acts as a complexing agent in copper, nickel, and zinc electroplating, controlling metal ion availability for uniform deposit quality.
Metal Cleaning: Formulated into alkaline cleaning solutions to remove oils, greases, and oxide films from metal surfaces before painting, plating, or coating.
Derusting & Descaling: Combined with surfactants to create effective metal pretreatment baths.
Alkaline Etching
● : Used in printed circuit board (PCB) manufacturing as part of the etching solution formulation.
In the textile industry, sodium pyrophosphate decahydrate is employed as:
Scouring Agent
● : Removes natural waxes, pectins, and metallic impurities from raw cotton and wool fibers.
Bleaching Stabilizer
● : Chelates trace metals that would otherwise catalyze the decomposition of hydrogen peroxide bleach, ensuring stable and uniform whitening.
Dyeing Auxiliary
● : Prevents metal-induced shade variations by sequestering hardness ions in dye bath water.
Soaping Agent
● : Used in the post-dyeing soaping step to remove unfixed reactive dyes, improving color fastness.
Pitch Control
● : Disperses sticky resinous deposits (pitch) in mechanical pulp processing.
Coating Formulations
● : Functions as a dispersant in paper coating color preparations, ensuring uniform pigment distribution.
De-inking
● : Aids in the removal of ink particles during the recycling of waste paper.
Drilling Fluid Additive
● : Acts as a deflocculant and viscosity modifier in water-based drilling muds, controlling rheology and preventing clay swelling.
Scale Inhibitor
● : Protects downhole equipment and surface facilities from scale deposition in produced water handling.
Ceramic Body Dispersant
● : Reduces the water demand of ceramic slips and glazes, enabling higher solids loading and improved rheology in slip casting.
Cement & Concrete Additive
● : Improves workability and reduces mixing water requirements in certain specialty cement formulations.
Sodium pyrophosphate decahydrate is approved as a food additive (E450iii) by the Codex Alimentarius, the European Food Safety Authority (EFSA), and the U.S. Food and Drug Administration (FDA) as GRAS (Generally Recognized As Safe) when used in accordance with Good Manufacturing Practices.
Function | Description | Typical Food Products |
Emulsifier | Promotes and stabilizes oil-in-water emulsions | Processed cheese, cheese spreads, salad dressings |
Sequestrant | Binds metal ions that catalyze oxidation or discoloration | Canned seafood, processed potatoes, fruit products |
Buffering Agent | Controls and stabilizes pH during processing and storage | Processed meat, poultry, and seafood products |
Texturizer | Modifies protein functionality for improved texture and water binding | Surimi, imitation crab, restructured meat products |
Water Retention Agent | Increases water-holding capacity, reducing cook loss | Processed meats, frozen seafood, marinated products |
Whipping Agent | Improves foam stability and overrun | Marshmallows, nougat, aerated confectionery |
Crystal Inhibitor | Prevents struvite crystal formation | Canned tuna, crab, and other canned seafood |
Processed Cheese & Cheese Analogs
● : TSPP is the primary emulsifying salt in processed cheese manufacturing. It sequesters calcium from casein proteins, enabling proper emulsification of fat and water phases to produce a smooth, uniform texture that melts cleanly.
Seafood Processing
● : Used to improve water retention, reduce drip loss during thawing, and protect color in frozen fish fillets, shrimp, and scallops.
Meat & Poultry
● : Enhances water-binding capacity and reduces cooking loss in processed meat products such as ham, sausages, and restructured poultry products.
Potato Products
● : Prevents after-cooking darkening (non-enzymatic browning) in processed potato products by chelating iron ions.
Baking Applications
● : Functions as a leavening acid component or dough conditioner in certain specialty baked goods.
Pet Food
● : Used as a gelling agent and texture modifier in canned pet food formulations.
