Silicon Dioxide

A synthetic amorphous silica produced as an extremely fine, low-density white powder. The dominant anti-caking and free-flow agent across powdered food, supplement, pharmaceutical, and feed applications.

Two physical forms reach the market: precipitated silica, made by acid neutralization of sodium silicate solutions, and fumed silica, made by high-temperature flame hydrolysis. Both are amorphous and clearly distinguished from crystalline silica, which has different toxicological status.

We supply food-grade Silicon Dioxide from manufacturers in China holding ISO, Halal, Kosher and other certifications relevant to the product and production.

Common market grades include precipitated silica with surface areas of 150 to 250 m²/g for general anti-caking, fumed silica at 200 to 380 m²/g for premium thickening and rheology control, food-grade with low absorbed-moisture specifications, and pharmaceutical grade compliant with USP, EP, and JP monographs for colloidal silicon dioxide.

Bulk and reduced-MOQ shipments. Batch-level COA covering loss on drying, loss on ignition, pH, surface area, heavy metals, and microbiology.

Silica is the most abundant compound in the earth's crust, but food-grade Silicon Dioxide is exclusively synthetic amorphous material, structurally distinct from the crystalline forms (quartz, cristobalite) that drive occupational silicosis concerns. Industrial production began in the 1940s with the development of pyrogenic (fumed) silica by Degussa and precipitated silica by Pittsburgh Plate Glass.

Precipitated silica is made by acidifying a sodium silicate (water glass) solution under controlled pH and temperature. The amorphous silica precipitates, is filtered, washed to remove sodium sulfate, dried, and milled to specification. Fumed silica is made by flame hydrolysis of silicon tetrachloride at approximately 1,800 °C, producing extremely fine primary particles that aggregate into a low-density powder of very high surface area.

Regulated as E551 in the EU, classified as Generally Recognized as Safe by the U.S. FDA under 21 CFR 172.480, and approved by JECFA without a numerical Acceptable Daily Intake limit for synthetic amorphous silica. The EFSA 2018 re-evaluation maintained the substance's safe status while requesting additional characterization data on particle size distribution.

Mechanism of action in finished products is physical: the high-surface-area particles coat the surface of host powders, absorb adsorbed moisture, and prevent the inter-particle bridging that causes caking. Above approximately 0.5 percent inclusion, flow properties of difficult powders such as garlic salt, onion powder, and high-fat seasoning blends improve dramatically.

Strategic positioning: Silicon Dioxide is one of the few additives where supplier choice is driven by surface chemistry rather than chemical purity. Specifying surface area, particle size, and tapped density rather than just assay is essential for reproducible performance.

• Anti-caking in powdered seasonings, salt, sugar, spice blends, and instant beverage mixes; typical inclusion 0.5 to 2 percent
• Free-flow agent for powdered dairy creamers, infant formula bases, and instant soups
• Carrier for liquid flavors, essential oils, and oil-soluble nutrients converted to free-flowing powders
• Tableting glidant in nutraceutical and pharmaceutical direct compression at 0.1 to 0.5 percent
• Defoamer in beer, fruit juice, and beverage filtration
• Thickener and suspension aid in toothpaste, where high-surface-area precipitated silica also serves as a mild abrasive
• Stabilizer in powdered colors and flavor encapsulates
• Animal feed and premix anti-caking; standard inclusion in vitamin and mineral premixes
• Clouding agent and suspension stabilizer in some beverage formulations