Fumed silica

Fumed silica is made from flame pyrolysis of silicon tetrachloride or from quartz sand vaporized in a 3000 °C electric arc.

[3] Major global producers are Evonik (who sells it under the name Aerosil), Cabot Corporation (Cab-O-Sil), Wacker Chemie (HDK), Dow Corning, Heraeus (Zandosil), Tokuyama Corporation (Reolosil), OCI (Konasil), Orisil (Orisil) and Xunyuchem(XYSIL).

Other uses include filler in silicone elastomer and viscosity adjustment in paints, coatings, printing inks, adhesives and unsaturated polyester resins.

[5] Fumed silica readily forms a network structure within bitumen and enhances its elasticity.

Due to its fineness and thinness, fumed silica can easily become airborne, making it an inhalation hazard capable of causing irritation.