Sodium metasilicate pentahydrate

Sodium Metasilicate Pentahydrate (CAS 10213-79-3, EC 600-279-4) is an inorganic sodium silicate salt supplied as a crystalline solid, also referenced as Sodium Silicate Pentahydrate or Sodium Metasilicate 5H2O. It carries no assigned E-code and is not classified as a food additive. The formula H2O3Si·5H2O·2Na reflects its stable pentahydrate crystalline form.

In water treatment, it functions as a corrosion inhibitor by forming a protective silicate film on metal pipe surfaces, reducing iron and lead leaching. In industrial cleaning and textile processing, its strong alkalinity drives saponification of fats and oils, while its buffering capacity maintains process pH. It also acts as a crosslinker in adhesive and coating formulations, reacting with polymers to build network structure.

The material is supplied in technical and industrial grades, compliant with REACH registration requirements applicable to EU markets. Standard packaging includes 25 kg bags and bulk quantities. Buyers should confirm grade specification against application requirements, particularly for water treatment approvals under national drinking water regulations.