Sodium Metabisulfite CAS#7681-57-4
High Chemical Purity and Crystalline Form – Sodium metabisulfite appears as a white crystalline or powdery solid, indicating stable quality and suitability for controlled industrial applications.
Characteristic Mild Sulfur Odor for Easy Identification – The slight sulfur smell allows for quick recognition during handling and processing, helping ensure correct usage and safety control.
Strong Reactivity at High Temperature – It decomposes under high heat to release sulfur and sodium oxides, making it useful in chemical reactions that require controlled decomposition and reducing properties.
Effective Reducing and Preserving Agent – Its ability to release reactive sulfur compounds makes it valuable in industries requiring antioxidant, preservative, or bleaching functions.
Products Description of Sodium Metabisulfite CAS#7681-57-4
Sodium metabisulfite (Na₂S₂O₅) appears as a white crystalline or powdery solid with a slight sulfur odor. It is toxic when inhaled and can cause strong irritation to the skin and tissues. When exposed to high temperatures, it decomposes and releases toxic sulfur and sodium oxide fumes.
Parameters
| Melting point | >300 °C (lit.) |
| bulk density | 1000-1200kg/m3 |
| density | 1.48 |
| refractive index | 1.474 |
| storage temp. | Store at +5°C to +30°C. |
| solubility | 540 g/L (20°C) |
| form | Powder/Solid |
| color | White to slightly yellow |
| Specific Gravity | 1.48 |
| Odor | Sulphorous |
| PH | 3.5-5 (50g/l, H2O, 20℃) |
| PH Range | 4.5 at 50 g/l at 20 °C |
| Water Solubility | 540 g/L (20 ºC) |
| Sensitive | Air & Moisture Sensitive |
| Merck | 148,638 |
| Exposure limits | ACGIH: TWA 5 mg/m3 |
| NIOSH: TWA 5 mg/m3 | |
| Stability: | Stable. Incompatible with strong oxidizing agents, strong acids. Contact with strong acids releases a poisonous gas. May be moisture and air sensitive. |
| InChIKey | HRZFUMHJMZEROT-UHFFFAOYSA-L |
| CAS DataBase Reference | 7681-57-4(CAS DataBase Reference) |
| EPA Substance Registry System | Sodium metabisulfite (7681-57-4) |
Safety Information
| Hazard Codes | Xn,Xi |
| Risk Statements | 22-31-41-36/37/38-52 |
| Safety Statements | 26-39-46-36-16 |
| RIDADR | 3260 |
| OEB | B |
| OEL | TWA: 5 mg/m3 |
| WGK Germany | 1 |
| RTECS | UX8225000 |
| TSCA | Yes |
| HS Code | 2832 10 00 |
| PackingGroup | III |
| Hazardous Substances Data | 7681-57-4(Hazardous Substances Data) |
| Toxicity | LD50 orally in Rabbit: 1540 mg/kg LD50 dermal Rat > 2000 mg/kg |
Product Application of Sodium Metabisulfite CAS#7681-57-4
Sodium metabisulfite exhibits strong reducing activity and is widely applied in the food industry as an antioxidant, preservative, and bleaching agent, including in products such as meat, wine, and preserved fruits. It is also extensively used in chemical processes such as textile printing and dyeing, papermaking and pulping, water treatment, and leather softening. In the pharmaceutical field, it serves as an intermediate and as an antioxidant for injectable preparations, and it is further utilized in photography, rubber processing, agriculture, and other industries. It should be noted that sodium metabisulfite releases toxic sulfur dioxide upon contact with acids. Therefore, it must be stored in a tightly sealed container in a cool, dry environment and kept away from acids and oxidizing agents.
