Sodium Metasilicate Pentahydrate
Water Glass Pentahydrate
- CAS
- 10213-79-3
- EC
- 600-021-3
- Sectors
- Water & Wastewater Treatment, Textiles, Leather & Paper
Sodium Metasilicate Pentahydrate (CAS 10213-79-3) is an inorganic sodium silicate salt, the pentahydrate form of sodium metasilicate, appearing as a white crystalline powder or granules and used mainly as a builder in detergents and cleaners, for corrosion inhibition in water treatment, and in textiles and paper deinking. It has a density of about 1.75 g/cm³, melting point around 72°C (loses water), highly soluble in water forming strongly alkaline solutions (pH 12-13), and insoluble in alcohols. Hygroscopic, it decomposes in acids releasing silica gel; produced by crystallizing sodium metasilicate solution.
Typical Properties
| Molecular formula | H2O3Si.5H2O.2Na |
|---|---|
| Molecular weight | 212.14 g/mol |
| Form | Solid |
| Color | White |
| Odor | odourless |
| Melting point | 1088°C |
| Density | 1.28 g/cm³ (liquid) |
| Water solubility | Soluble in cold water. |
| pH | 12,5 (in aqueous solution: 10 g /l , 20 °C) |
| GHS signal word | Danger · Corrosive, Irritant / harmful, Health hazard |
| HS code | 28391100 |
| Grades available | 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 Metasilicate Pentahydrate
Applications
Used in detergents and cleaners as a builder and pH adjuster; in water treatment for corrosion inhibition; in adhesives, fireproofing, and textiles; in laundry, dairy, metal, and floor cleaning; in paper deinking and as a buffering agent in cosmetics.
Safety & Risks
Highly corrosive, causes severe skin burns, eye damage, and respiratory irritation; do not breathe dust or vapors. Avoid contact with acids or metals; wear protective gloves, clothing, and eye/face protection. Hazard Class 8; may be harmful if swallowed or inhaled; ensure good ventilation.
Packaging
Packaged in 25kg polypropylene bags or drums with inner liners; store in tightly closed containers in cool, dry areas to prevent moisture absorption.