Character & Purpose: White or buff crystal powder. Mainly used in
printing and dyeing, medicine, tanning, etc.
Packing: 25 Kg PP/PE BAG
Formula: Na2S2O5
Standard:
| Item | Spec. | Typical Results |
| Na2S2O5/% | 96 Min. | 97.68 |
| Sodium Metabisulphite(as SO2)/% | 65 Min. | 65.81 |
| Iron Content/% | 0.005 Max. | 0.003 |
| Water-insoluble/% | 0.05 Max. | 0.039 |
| PH Value | 4.0-4.6 | 4.5 |
| Heavy Metal(as Pb)/% | 0.001 Max | PASS |
| As/% | 0.0002 Max | PASS |