Colloidal silicon dioxide (often written as colloidal silica or silicon dioxide, colloidal) is a very fine, powdery form of silicon dioxide (SiO2) made up of extremely small particles dispersed in a medium (usually air or liquid).
What it is
• It’s essentially purified sand (silica) processed into microscopic particles.
• “Colloidal” means the particles are so small they remain evenly distributed rather than settling quickly.
Common uses
You’ll find it in a wide range of products:
1. Food industry (additive E551)
• Used as an anti-caking agent to keep powders free-flowing.
• Common in:
• Powdered milk
• Spice mixes
• Salt
• Protein powders
2. Pharmaceuticals & supplements
• Helps powders flow smoothly during tablet/capsule production.
• Acts as a stabilizer or thickening agent.
3. Cosmetics & personal care
• Use