Item No Index Measured Value Appearance White powder Compliance index Specific surface area of nitrogen adsorption m/g 200±10 200 Sio2- content >99.8 99.9% PH 3.7-4.5 4.19 Volatile matter % at 105 �ºC â?¤3.0 0.82 Tamping density g/dm�³ 30-60 31 Sieve residue(45�¼m) mg/kg â?¤250 19.93 Fumed silica is a very useful industrial chemical used in a variety of industrial and consumer products. Fumed silica poses a variety of health hazards to workers in various end-use industries and to those using products that use fumed silica. 1. in various resin additives, medicine, food and other fileds. 2. rubber, sealant, silica gel, adhesive, tile grout etc. 3. paint, coating, UPR, 4. CMP suspension etc; 5. Digital photo paper etc.