STPP Indexes Industrial Grade Food Grade
Assay Na5P3O10 % ≥ 94.0 94.0 P2 O 5 % ≥ 57.0 57.0
Water Insoluble Matter % ≤ 0.15 0.05 Iron(Fe) % ≤ 0.015 0.015 PH value (1% water solution) 9.2-10.0 9.5-10.0
Heavy Metal (as Pb) % ≤ 0.001
Arsenic (As) % ≤ 0.0003
Fluoride (F) % ≤ 0.003
Whiteness % ≥ 90 90
Ignition loss 1.0 / density (g/cm3) 0.35-0.9 0.35-0.9
Phase I 10-30 10-30
Assay Na5P3O10 % ≥ 94.0 94.0 P2 O 5 % ≥ 57.0 57.0
Water Insoluble Matter % ≤ 0.15 0.05 Iron(Fe) % ≤ 0.015 0.015 PH value (1% water solution) 9.2-10.0 9.5-10.0
Heavy Metal (as Pb) % ≤ 0.001
Arsenic (As) % ≤ 0.0003
Fluoride (F) % ≤ 0.003
Whiteness % ≥ 90 90
Ignition loss 1.0 / density (g/cm3) 0.35-0.9 0.35-0.9
Phase I 10-30 10-30