Sodium Hexametaphosphate
Graham's Salt, SHMP
- CAS
- 10124-56-8
- EC
- 233-343-1
- Food Code
- E452
- Sectors
- Water & Wastewater Treatment, Food & Nutrition
Sodium Hexametaphosphate (CAS 10124-56-8), also known as Graham's salt or SHMP, is a white granular polymeric metaphosphate salt consisting of a mixture of polymeric metaphosphates, supplied for water treatment scale inhibition and food processing as an emulsifier and moisture retainer. Available in Food Grade and Technical Grade, it is highly hygroscopic and readily soluble in water, forming a clear solution with a pH of 5.8-7.3 at 1%.
SHMP is a powerful sequestrant, forming stable complexes with calcium and magnesium ions. In food processing (E 452i) it acts as an emulsifier, texturizer, and moisture retainer in processed meats, seafood, dairy products, and beverages.
Technical applications include water treatment for scale and corrosion inhibition, deflocculation in ceramics, drilling fluids, and detergent formulations. It is produced by thermal condensation of sodium metaphosphate and consists of a mixture of polymeric metaphosphates.
Typical Properties
| Molecular formula | H6O18P6.6Na |
|---|---|
| Molecular weight | 101.96 g/mol |
| Appearance | white granular solid |
| Form | Solid |
| Color | White |
| Odor | odorless |
| Melting point | 616°C |
| Boiling point | 1500°C |
| Density | 2.181 |
| Water solubility | Soluble in water. Insoluble in organic solvents |
| HS code | 2835390000 |
| Grades available | Food Grade, Technical Grade |
Typical literature values for identification; lot-specific results are stated on the certificate of analysis (COA) and the safety data sheet (SDS) that accompany every delivery.
Sodium Hexametaphosphate
Applications
Widely used in water treatment as a scale inhibitor in EDI, RO, and NF systems. In the food industry, it improves water retention in meats, prevents oxidation, and enhances texture in soy products. Also applied in detergents, ceramics as a dispersant, paints, and metal finishing.
Safety & Risks
Generally safe but can irritate eyes, skin, and respiratory tract. Avoid strong acids or oxidizers to prevent heat or decomposition. Use PPE and ventilate areas. Not hazardous for transport; store dry to avoid moisture.
Packaging
Typically in 25kg polypropylene bags with PE liners or 50kg fiber drums. Store in cool, dry, ventilated spaces away from incompatibles.