Calcium silicate

Calcium silicate (CAS 1344-95-2), also designated E552 in food and pharmaceutical applications, is an inorganic mineral compound used primarily as an anticaking agent, flow aid, and functional filler.

Where is Calcium silicate used?

• Food and pharmaceutical manufacturing: prevents caking in powdered products such as table salt, spice blends, and tablet formulations; in table salt it improves flow under high humidity conditions.
• Rubber and plastics: reinforcing filler and processing aid that improves dimensional stability and surface finish in molded components
• Building and construction: core material in fire-resistant boards, insulation panels, and ceiling tiles
• Paper manufacturing: functional filler that improves opacity, printability, and sheet formation in specialty paper grades
• Binder for refractory materials.
• Absorbent for liquids and gases.
• Dental cements for furcal perforation repair.

Formulation notes

• In food applications, use is limited to 5% in baking powder and 2% in table salt.
• Calcium silicate board must not be in direct contact with flame.

Typical specification

• Absorbs up to 2.5 times its weight in liquid while remaining a free-flowing powder.
• Board thicknesses available are 25, 30, 40 and 50 mm ± 1.2 mm.
• Thermal conductivity (λ) is 0.060 W/mK at 10°C.
• Maximum service temperature of the board is 1100°C.

Regulatory status

• Has the INS number 552.
• Board is certified non-combustible Euroclass A1 (formerly Class 0).

Frequently asked questions about Calcium silicate

What purity basis is calcium silicate specified on?

Calcium silicate is specified on a minimum 87% SiO2 basis.

In which applications is calcium silicate used beyond construction and food?

Calcium silicate is used in chromatography, in acid mine drainage remediation to neutralize active acidity and raise pH, and in ceramic manufacturing by tile factories to improve performance parameters.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.