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 refers to a family of sodium salts of pyrophosphoric acid (H₄P₂O₇). The term commonly denotes two distinct compounds:
Compound | Chemical Formula | CAS Number | E-Number | Common Abbreviation |
Tetrasodium Pyrophosphate | Na₄P₂O₇ | 7722-88-5 | E450(iii) | TSPP |
Sodium Acid Pyrophosphate | Na₂H₂P₂O₇ | 7758-16-9 | E450(i) | SAPP |
Both are white, crystalline powders that are highly water-soluble and function as chelating agents, emulsifiers, buffering agents, and dispersants. The core difference lies in their pH behavior and specific application niches.
At a molecular level, the pyrophosphate anion (P₂O₇⁴⁻) consists of two phosphate tetrahedra linked by a shared oxygen atom (a P–O–P bridge). This structure gives it exceptional metal-ion-binding capacity — the foundation of nearly all its industrial uses.
Choosing between TSPP and SAPP comes down to pH requirements and intended function. Here is a side-by-side comparison:
Property | Tetrasodium Pyrophosphate (TSPP) | Sodium Acid Pyrophosphate (SAPP) |
Aqueous pH (1% solution) | ~10.0 – 10.5 (alkaline) | ~4.0 – 4.5 (acidic) |
Primary Function | Sequestrant, dispersant, alkaline buffer | Leavening acid, acidulant, pH control |
Key Industries | Detergents, water treatment, ceramics, oil drilling, metal finishing | Baking, processed potatoes, canned seafood, meat processing |
Metal Chelation Strength | Strong (binds Ca²⁺, Mg²⁺, Fe²⁺/Fe³⁺) | Moderate (pH-dependent) |
Typical Packaging | 25 kg bags, 50 lb bags, supersacks, bulk | 25 kg bags, 50 lb bags, fiber drums |
Solubility in Water | ~6.2 g/100 mL at 25°C (anhydrous) | ~12 g/100 mL at 25°C |
Sodium pyrophosphate is a workhorse chemical across multiple industries. Below are the major non-food industrial uses, organized by sector.
TSPP is a classic builder in heavy-duty detergents and industrial cleaners. Its functions:
Sequesters hardness ions (Ca²⁺, Mg²⁺), preventing them from interfering with surfactants
Deflocculates soil particles, keeping dirt suspended in wash water
Provides alkalinity to enhance cleaning performance
Prevents re-deposition of removed soils onto fabric or surfaces
TSPP is particularly effective in automatic dishwashing detergents, metal degreasers, and commercial laundry formulations. It is often blended with STPP (sodium tripolyphosphate) and sodium metasilicate for synergistic performance.
In boiler water, cooling towers, and industrial water systems, TSPP acts as:
Scale inhibitor:Chelates Ca²⁺ and Mg²⁺ to prevent CaCO₃ scale formation on heat exchanger surfaces
Corrosion control:Forms a thin protective film on metal surfaces
Iron sequestration:Ties up dissolved iron to prevent "red water" staining and iron oxide deposits
Typical dosage rates range from 2–15 ppm, depending on water hardness and system conditions.
TSPP is widely used in:
Electroplating:As a complexing agent in copper, nickel, and zinc plating baths to control metal ion availability
Metal cleaning:Removes rust, scale, and oxide layers from ferrous and non-ferrous surfaces
Anodizing:As an electrolyte additive for aluminum anodizing processes
In ceramic slip preparation, TSPP serves as a powerful deflocculant (dispersant):
● Reduces water demand in clay slips by 20–40%
● Improves slip fluidity at lower moisture content
● Enables higher solids loading in casting slips
● Prevents particle agglomeration during storage
Typical addition: 0.1–0.5% by weight of dry clay body.
In drilling fluid formulations, TSPP functions as:
Viscosity reducer:
● Breaks down clay flocs in water-based drilling muds
Shale inhibitor:
● Prevents cuttings dispersion
Calcium scavenger:
● Removes Ca²⁺ contamination from cement, anhydrite, or formation brines
Scouring aid:
● Sequesters metal ions that would otherwise interfere with peroxide bleaching
Dyeing auxiliary:
● Prevents metal-dye complexes that cause shade dulling
Soaping agent:
● Improves removal of unfixed dye
Pitch control agent:
● Disperses resinous deposits
Bleaching stabilizer:
● Chelates trace metals that catalyze peroxide decomposition
Coating dispersant:
● Stabilizes pigment slurries for paper coating
Sodium pyrophosphates are approved food additives under the E450 designation in the EU and are Generally Recognized as Safe (GRAS) by the U.S. FDA for specified food uses. Their food functions are diverse:
Function | Application Examples | Mechanism |
Emulsifier | Processed cheese, cheese spreads, dairy products | Disperses protein and fat phases; improves meltability and texture |
Water-binding agent | Processed meat, poultry, seafood | Increases water-holding capacity; reduces cooking loss |
Sequestrant | Canned seafood (tuna, crab, shrimp) | Chelates iron and magnesium to prevent struvite crystal formation |
pH Buffer | Puddings, desserts, sauces | Maintains consistent pH during processing and shelf life |
Texturizer | Imitation cheese, processed potato products | Improves firmness and mouthfeel |
Whipping agent | Marshmallows, aerated confections | Stabilizes foam structure |
Function | Application Examples | Mechanism |
Leavening acid | Cakes, muffins, pancakes, biscuits, refrigerated doughs | Reacts with sodium bicarbonate to release CO₂ at controlled rate |
Color retention | Processed potatoes (french fries, hash browns) | Chelates iron to prevent after-cooking darkening |
pH adjuster | Canned vegetables, fruit fillings | Maintains acidic pH for preservation |
Curing accelerator | Cured meat products | Accelerates color development in combination with nitrites |
STPP (Na₅P₃O₁₀) contains three phosphate units, while pyrophosphate contains two. STPP is the dominant builder in household detergents and is also widely used in food (E451) for water binding in meat and seafood. Pyrophosphate has stronger chelation per phosphate unit and is preferred where high metal-binding capacity is needed at lower dosage.
No. Baking powder is a complete leavening system containing sodium bicarbonate (the alkali) plus one or more leavening acids and a starch filler. SAPP is one of several leavening acids that can be used in baking powder formulations — others include monocalcium phosphate (MCP), sodium aluminum phosphate (SALP), and glucono-delta-lactone (GDL).
Yes. In some food applications (e.g., processed cheese), a blend of TSPP and SAPP provides a balanced pH and optimized emulsification. In industrial water treatment, TSPP may be blended with SAPP or other phosphates for tailored scale inhibition.
