Silicon Dioxide, E551, CAS no.7631-86-9, white powder. Silicon dioxide (SiO2), also known as silica, is a natural compound made of two of the earth's most abundant materials: silicon (Si) and oxygen (O2). Silicon Dioxide is a common additive in the production of foods, where it is used primarily as a flow agent in powdered foods, or to absorb water in hygroscopic applications used in silica gel, control moisture levels to avoid prevent certain goods from going bad. It is often used in cheese, fat spreads, confectionery, dried vegetables, etc. As an experienced Silicon Dioxide manufacturer and supplier, we has been supplying and exporting Silicon Dioxide for almost 10 years, please be assured to buy from us. Any inquiries about price and the market trend please feel free to contact us, we will reply you within 1 working day. Silicon Dioxide Specification Item Standard Appearance White powder Purity (SiO2, %) 96 Oil absorption (cm3/g) 2.0~ 3.0 Loss on drying (%) 4.0~ 8.0 Loss on ignition (%) 8.5 BET (m2/g) 170~ 240 pH (10% solution) 5.0~ 8.0 Sodium sulfate (as Na2SO4, %) 1.0 Arsenic (As) 3mg/kg Lead (Pb) 5 mg/kg Cadium (Cd) 1 mg/kg Mercury (Hg) 1 mg/kg Total heavy metals (as Pb) 20 mg/kg Total plate count 500cfu/g Salmonella spp./ 10g Negative Escherichia coli/ 5g Negative