| Actual | Limit | |
| Assay: | 99.7% | ≥95.0% MgO |
| Insoluble Matter: | <0.02% | 0.02% max. |
| Water-soluble substances: | 0.01% | 0.4% max. |
| Loss on ignition: | 0.17% | 2.0% max. |
| Ammonium hydroxide precipitate: | <0.001% | 0.02% max. |
| Chloride: | <0.0005% | 0.01% max. |
| Nitrate: | <0.0005% | 0.005% max. |
| Sulfate and sulfite(as SO4): | <0.002% | 0.02% max. |
| Barium: | <0.001% | 0.005% max. |
| Calcium: | 0.0004% | 0.05% max. |
| Heavy Metals: | <0.0001% | 0.003% max. |
| Iron: | 0.0006% | 0.01% max. |
| Potassium: | <0.0001% | 0.005% max. |
| Sodium: | <0.001% | 0.5% max. |
| Strontium: | <0.0001% | 0.005% max. |