Silica for fine-sil520a toothpaste is amorphous powder, tasteless, insoluble in water or acid, chemically inert, and has good compatibility with fluoride and other raw materials in toothpaste. The structure and particle size of silica can be controlled by production conditions. According to different types of toothpaste, three products are produced: friction type, mixed type and thickening type.
Fine-sil520a series products are tested and meet the light industry standard of the people’s Republic of China QB / t2346-97
| project | Friction type | mixed type | Thickening type |
| Silica content(%) | ≥95 | ≥98 | ≥98 |
| appearance | White powder, no impurities by visual inspection | White powder, no impurities by visual inspection | White powder, no impurities by visual inspection |
| Whiteness（WG）% | ≥93 | ≥98 | ≥98 |
| PH (5% aqueous dispersion) | 6.5-8.5 | 6.5-8.5 | 6.5-8.5 |
| Below screen 320 mesh (%) | ≥98 | ≥99 | ≥99 |
| 1050C volatiles (%) | ≤10 | ≤10 | ≤10 |
| Loss on drying（9000C)% | ≤8.3 | ≤6 | ≤6 |
| Water absorption value(ml/20g) | 17-20 | 30-42 | 45-60 |
| Sulfate (calculated as Na2SO4)% | ≤0.4 | ≤0.4 | ≤0.4 |
| Chloride (calculated as NaCl)% | ≤0.1 | ≤0.1 | ≤0.1 |
| sulfide | 无 | 无 | 无 |
| Heavy metal (PB) content (mg / kg) | ≤20 | ≤20 | ≤20 |
| Arsenic (as) content (mg / kg) | ≤2 | ≤2 | ≤2 |
| Total bacteria (CFU / g) | ≤200 | ≤200 | ≤200 |