Indexes		Industrial Grade	Food Grade
CrO3 Purity%≥		99.7	99.5
Water insoluble% ≤		0.01	0.02
Sulphates ( SO4)% ≤		0.06	0.15
Na%≤		0.05	0.05
Cl%≤		0.05	0.05
Fe%≤		0.05	0.05