Sodium hydrosulfite
Sodium hydrosulfite (CAS 7775-14-6), with the molecular formula Na2S2O4 and a molecular weight of 174.11 g/mol, is a powerful reducing agent. It is commonly utilised in various industrial applications, primarily as a reducing agent in dyeing processes, particularly for vat dyes and indigo. It also finds use in the pulp and paper industry for bleaching and in chemical synthesis as a versatile reagent.
- IUPAC
- Sodium dithionite,Sodium hypodisulfite
- Synonyms
- Sodium dithioniteSodium hypodisulfite
Textile Dyeing
Sodium hydrosulfite is extensively employed as a reducing agent in the application of vat dyes and indigo dyes to cellulosic fibres. Its ability to reduce insoluble dyes to their soluble leuco form allows for effective dyeing.
Pulp and Paper Bleaching
In the pulp and paper industry, it serves as a bleaching agent to improve the brightness of paper pulp. It effectively reduces coloured impurities without significantly degrading the cellulose fibres.
Chemical Synthesis
As a robust reducing agent, sodium hydrosulfite is a valuable reagent in organic and inorganic synthesis. It can be used for the reduction of various functional groups and in specific synthetic pathways.
Clay Bleaching
It is also used for bleaching clays, improving their colour and suitability for applications in ceramics and paints.
| Molecular weight | 174.11 |
|---|---|
| Linear formula | NaO2SSO2Na |
| Assay | ≥82% (RT) |
| Grade | technical |
Hazard statements
- H251Self-heating; may catch fire
- H302Harmful if swallowed
Precautionary statements
- P235Keep cool
| Transport (UN / ADR) | UN 1384 4.2 / PGII |
|---|---|
| Water hazard class (WGK, DE) | 1 |
| Hazard codes (EU) | Xn |
| Risk statements (R) | 7-22-31 |
| Safety statements (S) | 7/8-26-28-43 |
| Supplemental hazards | Contact with acids liberates toxic gas. |
| Cation traces | Ca: ≤50 mg/kgCd: ≤5 mg/kgCo: ≤5 mg/kgCr: ≤5 mg/kgCu: ≤5 mg/kgFe: ≤5 mg/kgK: ≤50 mg/kgMg: ≤5 mg/kgMn: ≤5 mg/kgNi: ≤5 mg/kgPb: ≤5 mg/kgZn: ≤5 mg/kg |
| Anion traces | chloride (Cl-): ≤50 mg/kg |
Hazard information is provided for guidance. Always consult the product Safety Data Sheet (SDS), available on request, before handling.
Documentation
Every batch ships with a Certificate of Analysis covering assay, identity and purity; the grade is confirmed against your enquiry. Safety Data Sheets and technical data sheets are available on request.
Supply & logistics
Samples for technical evaluation; bulk MOQ by grade and packaging. In-stock material ships in 7–10 working days, worldwide, with full export documentation.
What is Sodium Hydrosulfite used for?
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Sodium hydrosulfite is primarily used as a reducing agent in textile dyeing (especially for vat and indigo dyes), for bleaching pulp and paper, and in general chemical synthesis.
What is the CAS number and formula for Sodium Hydrosulfite?
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The CAS number for Sodium Hydrosulfite is 7775-14-6, and its chemical formula is Na2S2O4.
What grade and purity does Tech Serve Solutions supply for Sodium Hydrosulfite?
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Tech Serve Solutions supplies Sodium Hydrosulfite in technical grade with an assay of ≥82%. We do not represent this product as USP, BP, or EP grade.
How should Sodium Hydrosulfite be handled safely?
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Sodium Hydrosulfite is a self-heating substance (H251) and is harmful if swallowed (H302). Contact with acids liberates toxic gas. Store in a cool, dry, well-ventilated area away from incompatible materials, and keep container tightly closed. Refer to the Safety Data Sheet (SDS) for comprehensive handling information.
How is Sodium Hydrosulfite packed, shipped, and exported?
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Sodium Hydrosulfite is packed and shipped according to UN 1384, Class 4.2, Packing Group II regulations. Tech Serve Solutions is experienced in exporting chemicals globally.
How can I request a sample or quote for Sodium Hydrosulfite?
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To request a sample or a quote for Sodium Hydrosulfite, please contact our sales team through the website or by phone, providing your specific requirements.
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