| Assay: | ≥99.0% FeSO4 · 7H2O |
| MAXIMUM ALLOWABLE | |
| Insoluble matter: | 0.01% |
| Chloride (Cl): | 0.001% |
| Phosphate (PO4): | 0.001% |
| Calcium (Ca): | 0.005% |
| Copper (Cu): | 0.005% |
| Magnesium (Mg): | 0.002% |
| Manganese (Mn): | 0.05% |
| Potassium (K): | 0.002% |
| Sodium (Na): | 0.02% |
| Zinc (Zn): | 0.005% |
| Ferric ion (Fe3+): | 0.1% |