| Appearance | White or slightly yellowish powder |
| Assay (purity) | ≥ 98% |
| Moisture content | ≤ 2% |
| pH (1% solution) | 9.0 – 11.0 |
| Odor | Characteristic, sulfur-like odor |
| Melting Point | 180-185°C |
| Solubility | Soluble in water and alcohol |
| Heavy Metals (as Pb) | ≤ 10 ppm |
| Arsenic | ≤ 2 ppm |
| Chloride (Cl) | ≤ 0.5% |
| Sulphate (SO4) | ≤ 0.05% |
| Loss on Drying | ≤ 1% |