silicon dioxide powder or silica. food additive e551

silicon dioxide amorphous pure silica white tooth powder anticaking agent prevents caking clumping e551 food additive sio2 nanoparticles toxic aerosil cosmetic products toothpaste ingredient chemical dispersed pyrogenic pharmaceuticals dangerous silicic oxide crystalline dietary supplements sand silicea precipitated hygroscopic compound hard abrasive antifoam calcium desiccant silica anti-caking agent oxide dust scattered dark surface