Sodium disulfite is an inorganic sodium salt composed of sodium and disulfite ions in a 2:1 ratio. It has a role as a food antioxidant. It contains a disulfite.
Corrosive
Irritant
⚠️ For information only; not a substitute for the official Safety Data Sheet (SDS).
Sodium disulfite is an inorganic sodium salt composed of sodium and disulfite ions in a 2:1 ratio. It has a role as a food antioxidant. It contains a disulfite.
| Physical Description | Sodium metabisulfite appears as a white crystalline or powder solid with a slight sulfur odor. Toxic by inhalation. Strongly irritates skin and tissue. Noncombustible, but may decompose to emit tox… |
| Color/Form | White hexagonal crystals or powder |
| Odor | In the presences of traces of water, it develops an odor of sulfur dioxide |
| Melting Point | greater than 302 °F (Decomposes) (NIOSH, 2024) |
| Boiling Point | Decomposes (NIOSH, 2024) |
| Density | 1.4 (NIOSH, 2024) - Denser than water; will sink |
| Solubility | 54 % (NIOSH, 2024) |
| Stability/Shelf Life | On exposure to air and moisture is slowly oxidized to sulfate. |
| Molecular Formula | Na2O5S2 |
| Molecular Weight | 190.11 g/mol |
| CAS | 7681-57-4 |
| SMILES | [O-]S(=O)S(=O)(=O)[O-].[Na+].[Na+] |
| InChIKey | HRZFUMHJMZEROT-UHFFFAOYSA-L |
| Catalog No | KC.1910236 |
| Pack sizes | 500GM · 1KG · 5KG |
⚠️ For information only; not a substitute for the official SDS.