Silicon Dioxide, CAS#7631-86-9
Appearance: It is a white, fluffy amorphous fine powder, odorless and tasteless, featuring a porous microstructure and large specific surface area.
Solubility: Practically insoluble in water, ethanol and dilute acids; soluble only in hot concentrated alkali solutions.
Stability & pH Performance: Chemically inert under normal conditions. The pH value of its 5% aqueous suspension is 4.0–8.5. It maintains excellent thermal stability under common food processing temperatures and does not react with most food raw materials.
Basic Function Features: It possesses outstanding anti-caking and flow-aiding performance. It can adsorb free moisture and separate powder particles to effectively prevent agglomeration, and can also be used as carrier, adsorbent and clarifying agent.
Silicon dioxide, characterized by the molecular formula SiO₂, presents as a white amorphous fine powder with porous structure. It is practically insoluble in water, ethanol and dilute acids, and dissolves only in hot concentrated alkaline solutions. Its aqueous suspension pH is between 4.0 and 8.5, and it features outstanding chemical inertness and thermal stability under routine food processing conditions. The substance is non-toxic under permitted dosage, and is commonly used as anticaking agent, flow regulator, carrier and clarifying agent in food industry. It can also be applied as grinding aid, anti-caking additive and adsorbent in multiple industrial fields.
| Chemical Properties | Parameter |
|---|---|
| CAS No. | 7631-86-9 |
| Molecular Formula | SiO₂ |
| Molecular Weight | 60.08 g/mol |
| Melting Point | 1713 °C |
| Boiling Point | 2230 °C |
| Density | 2.2 g/cm³ |
| Loss on Drying | ≤ 5.0 % |
| Loss on Ignition | ≤ 8.5 % |
| pH (aqueous suspension, 5% w/w) | 4.0–8.5 |
| Solubility | Insoluble in water, ethanol and dilute acids; soluble in hot concentrated alkali |
| Appearance | White amorphous fine powder |
| Odor | Odorless, tasteless |
| Sensitivity | Low moisture absorption, porous |
| Storage Temp | Store at room temperature, keep sealed and dry |
| Stability | Stable, chemically inert; incompatible with hydrofluoric acid and strong fluorinating agents |
| Heavy Metal (Pb) | ≤ 5 mg/kg |
| Arsenic | ≤ 3 mg/kg |
| InChIKey | VYPSYNLAJGMNEJ-UHFFFAOYSA-N |
| NIST Chemistry Reference | Silicon dioxide (7631-86-9) |
| EPA Substance Registry System | Silica, amorphous |
| Safety Information | Details |
|---|---|
| GHS Classification | Warning |
| Hazard Statements | H315: Causes skin irritation; H319: Causes serious eye irritation; H335: May cause respiratory irritation |
| Precautionary Statements | P261, P264, P280, P302+P352, P304+P340, P305+P351+P338 |
| Risk Statements | R36/37/38 |
| Safety Statements | S26, S36, S37/39 |
| WGK Germany | 1 |
| RTECS | VV7330000 |
| Grade | Food Grade |
| TSCA | Yes |
| HS Code | 28112200 |
| Hazard Description | Irritating to eyes, respiratory system and skin |
| Handling Advice | Avoid dust inhalation; wear safety goggles, dust mask and protective gloves; avoid generating dust clouds |
| Storage Requirement | Keep tightly sealed in cool dry place, away from hydrofluoric acid and strong fluorides |
This compound is widely used as an anticaking agent and flow aid in powdered food products including powdered milk, spice blends, seasoning powder, instant beverage powder, baking powder, powdered sugar and soup premixes. It acts as a carrier for food colors, flavors and nutritional additives. It also serves as clarifying agent in wine and beverage production, anti-caking additive for feed additives, adsorbent for purification, and filler and anti-blocking agent in rubber, plastic and cosmetic industries. Due to its high porosity and stable inert property, it is also adopted in chromatographic separation, catalyst carrier and moisture adsorption applications.
