what is fumed silica

Produced by a flame hydrolysis of volatile silicon compounds, fumed silica serves as an additive to various solids, powders, liquids and coatings. Also known as pyrogenic silica, amorphous silica and silicon dioxide, fumed silica consists of submicron particles that move between larger particles, creating a surface layer that acts as a lubricant. Consequently, fumed silica is often used as an anti-caking agent. Its ability to increase viscosity also makes fumed silica a popular choice as a thickening agent.

Synonyms: colloidal silica, fumed silica, HDK, hydrophilic fumed silica, pyrogenic silica, silica fumed, silicon dioxide, synthetic amorphous pyrogenic silica
INCI: Silica
Chemical formula: SiO2
CAS # 7631-86-9

buy fumed silica in various grades

Use the links below to view all package sizes for these specific products:

HDK® N20 Hydrophilic Pyrogenic Silica WACKER

Product Specifications

AppearanceWhite powder
SolubilitiesSlightly soluble in water
Freezing point3092oF
Molecular weight60.09
Weight per gallon1.0 lb/gal
ClassFumed Silica
Hydrophilic Fumed Silica


Fumed Silica uses include adhesives & cements, cosmetics, food additive, free flow agent, gel coats, ink, paint & coatings, pharmaceuticals, polyester resins, PVC cement, sealants, silicone rubber, thixotropic agent, unsaturated polyester resin.

  • Coatings and Construction: Fumed Silica is used in polyester resins, PVC cement as universal thickening agent and an anticaking agent.
  • Food and Nutrition: Fumed Silica is used to enhance the fat's effectiveness and acting as an effective stabilizer of Pickering emulsions that replaces fat fractions. Thickening, anti-settling and emulsification.
  • Personal Care: Fumed Silica is used in the formulation of products like toothpaste; antiperspirants; dental powders; sunscreen products; nail polish; fragrances; lipstick; powders; makeup and creams; and hair care.
  • Pharmaceuticals: Fumed Silica is used as a disintegrant, glidant, filler, lubricant, binder and sorbent.
  • Plastics: Fumed Silica is used as a reinforcing agent for silicone rubber, coatings and unsaturated resin thickener, ultrafine silica gels and aerogels used primarily as paint matting agents, thickeners, plastic film opening agent.

Quick Answers

Fumed silica, also known as pyrogenic silica because it is produced in a flame, consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles which then agglomerate into tertiary particles.

Knowing where to get fumed silica is probably just the beginning of your company’s chemical requirements, and Brenntag can fulfill them all in one place. As a leading fumed silica distributor in the United States and North America, Brenntag can provide the right product at a competitive price for your company.

Your best approach will be to contact Brenntag North America. Brenntag is the established global market leader in ingredient and chemical distribution and can fully supply all your acetic acid and other chemical needs.

Fumed silica is available in bags and super sacks.

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