Fumed silica is an amorphous silica product obtained by high-temperature hydrolysis of organohalosilane in a hydrogen-oxygen flame. Its primary particle size is between 7 and 40 nanometers, and its specific surface area is generally greater than 100m2/g. Very high, the silica content is not less than 99.8%. Fumed silica has been industrially produced since the 1940s. In the past few decades of industrial production, no cases of silicosis caused by inhalation of fumed silica have been found. The International Association for Research on Cancer (IARC) stated that there is currently insufficient evidence to prove that synthetic amorphous silica is carcinogenic to humans or experimental animals. On the contrary, IARC has listed crystalline silica as a carcinogen. In addition, the European Union The directive document (67/548/EEC) also states that amorphous silica is not a dangerous substance. Due to its good stability, physiological inertness, thickening properties, etc., it can be widely used in the field of daily necessities.