Sodium metasilicate pentahydrate

Sodium metasilicate is the ionic chemical compound with the formula Na2SiO3, and the main component of commercial sodium silicate solutions. It is colorless crystalline, deliquescent, and hygroscopic, soluble in water to give an alkaline solution.


Chemical name: Sodium Metasilicate Pentahydrate

CAS No.: 10213-79-3

Molecular formula: Na2SiO3 * 5H2O

Standard executed: HG/T 2568-2008

Packaging: in 25KG/1000KG PP woven bag with PE liner


Technical specification

Items Standards
Na2O content, %
28.3- 30.0
SiO2 content, %
Water insoluble matter content, %
Ferric (Fe) content, ppm
pH (1.0% aqueous solution, 25°C)
12- 13
Whiteness, %
Bulk density. g/cm3
Inorganic Salt; Synthetic Reagent
Melting point
1088°C (1990°F, 1361 K)
Solubility in water
Soluble in cold water
stored in a cool and dry place with pallet or plate
Shelf life/Retest
24 months
White powder or granular


Sodium metasilicate is a silicic acid salt, classified as an inorganic salt product. It is non-toxic, harmless, and odorless, with purifying, emulsifying, moistening, dispersing, permeating, and PH buffering abilities. As an aqueous solution, it is capable of hygroscopy and deliquescence when in contact with air. Its forms include anhydrous, pentahydrate, and nonahydrate compounds.

It is estimated to be generally less aggressive and safer to use than caustic soda (sodium hydroxide). Sodium silicate reacts with metal oxides to establish a protective film on metal surfaces, reducing the alkali’s tendency to corrode and dissolve metals. This sort of protection is maintained as long as minute amounts of soluble silica remain in the presence of water.

In conjunction with surfactants, sodium metasilicate aids the neutralization of acidic soil, the deflocculation of particulate soil, and the emulsification of oily and greasy soil. Furthermore, it enhances the suspension of removed soil and prevents its reaccumulation. The grease and dirt deposits get dispersed into small, suspended particles that rinse away without redepositing on freshly washed surfaces.

As a builder, sodium metasilicate enhances/maintains the surfactant’s cleaning efficiency by balancing water hardness. Also, it has the highest active alkalinity and PH buffering index among inorganic electrolytes, which enables its strong moistening, emulsifying, and saponifying effect on fats. For this reason, it’s broadly used in manufacturing high-efficiency in soaps, detergents, and metal cleaners. Sodium metasilicate pentahydrate can substitute STPP in detergent formulas to increase their cleaning efficiency while reducing environmental pollution.

Sodium metasilicate is also applicable in fireproofing mixtures, insecticides, fungicides, and antimicrobial compounds, as well as in dairy cleaning, paper deinking, and washing carbonated drink bottles. It’s a chemical intermediate for silica gel catalysts, an active ingredient in adhesives, and a bleaching aid to stabilize hydrogen peroxide. Furthermore, it’s utilized as a clay deflocculant in the ceramics industry and a boiler compound. In combination with other salts such as sodium bicarbonate, it creates a paint stripper for aluminum.

Stability/Shelf life


Recommended storage: stored in a cool and dry place with pallet or plate.


Sodium metasilicate is formed by the high-temperature fusion of silicon dioxide with sodium carbonate. 

Industry use

Sodium metasilicate pentahydrate is commonly used as a base for dish and laundry detergent formulations and a bleaching aid. It has a major utility as a builder of the cleaning efficiency of the surfactant in soaps and detergents. Other applications include deinking paper, laundry, metal, and floor cleaning products. 

Consumer use

The multiple hydrates of sodium metasilicate are used in soap and bath/washing products. They are also used as anti-corrosion agents in boiler-water feeds.


Soluble in cold water, to form highly alkaline solutions. Hydrolyzes in hot water. Insoluble in alcohol, acids, and salt solutions.

Common synonyms

  • Silicic Acid (H2SiO3)
  • Disodium Salt
  • Pentahydrate Silicic Acid
  • Disodium Salt Pentahydrate
  • Disodium Oxosilanediolate Pentahydrate

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Sodium silicate is commonly used to produce synthetic detergent in a spray drying tower to form hollow particles, so as to have good free flowing property of the synthetic detergent. Sodium metasilicate pentahydrate is mostly used for production of concentrated synthetic detergent by agglomeration method.

No, STPP Group does not manufacture Sodium metasilicate pentahydrate. We are the sole agent of one of China’s top 2 manufacturers YUEDA INDUSTRIAL.

Our MOQ for Sodium metasilicate pentahydrate is 25 tons in 1*20’’GP.

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