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Product Name: Sodium Thiosulfate
Synonyms: Disodium thiosulphate, Hyposulphite of soda
Chemical Formula: Na2S2O3·5H2O
CAS Number: 10102-17-7
Recommended Use: Laboratory reagent, photographic fixer, medical antidote for cyanide poisoning, water treatment, dechlorination
Supplier Information: Chemical manufacturers and distributors across North America, Europe, and Asia
Emergency Contact: Refer to local poison control center or supplier emergency helplines
GHS Classification: Substance not classified as hazardous under GHS criteria
Pictograms: Generally not required, but eye irritation may occur
Signal Word: Not applicable due to low toxicity
Hazard Statements: May cause mild skin and eye irritation on prolonged or repeated contact
Precautionary Statements: Avoid dust inhalation, use in well-ventilated areas, wear eye protection
Other Hazards: Hygroscopic, absorbs moisture from air, may produce toxic sulfur oxides under fire conditions
Chemical Name: Sodium Thiosulfate Pentahydrate
Concentration: >99%
Impurities: Trace amounts of sodium sulfite, sodium sulfate may be present due to production processes
Molecular Weight: 248.18 g/mol
Structure: Two sodium ions, one thiosulfate anion, five water molecules
Other Ingredients: None significant for hazard assessment
Inhalation: Remove person to fresh air, seek medical attention if symptoms persist
Skin Contact: Rinse with plenty of water, remove contaminated clothing, obtain medical advice for irritation
Eye Contact: Flush with water for at least 15 minutes, consult a doctor if discomfort continues
Ingestion: Rinse mouth with water, drink water to dilute, do not induce vomiting, seek medical assessment if large amounts swallowed
General Notes: No specific antidote needed, supportive care usually enough due to low toxicity
Suitable Extinguishing Media: Water spray, carbon dioxide, foam, dry chemical
Unsuitable Media: None known for this substance
Specific Hazards: Can decompose upon heating above 100°C releasing toxic sulfur oxides and sodium oxides
Protective Equipment for Firefighters: Self-contained breathing apparatus, full protective suit
Fire-Fighting Instructions: Evacuate area if fumes present, avoid breathing vapors, cool containers with water spray to prevent rupture
Explosion Risk: Not explosive, low fire risk under normal storage
Personal Precautions: Wear safety goggles, gloves, avoid dust formation, ventilate area
Environmental Precautions: Prevent spill from entering sewers and watercourses, sweep up to avoid waterway contamination as large discharges may affect aquatic life
Cleanup Methods: Contain and collect spillage, transfer to labeled waste container for proper disposal, clean contaminated surfaces with water
Handling Spillage: Use non-sparking tools, minimize dust generation, wash area after material off the surface
Safe Handling: Avoid dust production, use only in well-ventilated locations, do not eat or drink while working with product
Hygiene Practices: Wash hands thoroughly after handling, remove contaminated clothing and wash before reuse
Storage Conditions: Keep container tightly closed, store in cool and dry location, protect from moisture and humidity
Incompatible Materials: Strong acids, oxidizers—can release sulfur dioxide gas if mixed
Packaging Materials: Store in polyethylene or glass containers, avoid contact with metals that may promote hazardous reactions
Control Parameters: Occupational exposure limits not established by OSHA or NIOSH for sodium thiosulfate
Engineering Controls: Use local exhaust ventilation in enclosed spaces, maintain clean working environment
Personal Protective Equipment: Chemical goggles, disposable dust mask or respirator (P2 or N95 for poorly ventilated settings), protective gloves (nitrile or latex)
General Protection: Apron or lab coat recommended if large quantities handled, always wash hands after use
Physical State: Crystalline solid
Color: White, transparent
Odor: Odorless
Melting Point: Loses water at 48°C, decomposes at 100°C
Boiling Point: Not applicable (decomposes before boiling)
Solubility: Soluble in water (70 g/100 mL at 20°C), insoluble in alcohol
pH (50 g/L at 25°C): 6.5-8.0
Relative Density: About 1.7
Vapor Pressure: Not applicable
Partition Coefficient: Not available
Evaporation Rate: Not volatile
Other Properties: Deliquescent, absorbs moisture from air rapidly
Chemical Stability: Stable at room temperature in dry air, loses water on exposure to heat or dry air
Reactivity: Reacts with acids to release sulfur dioxide, reacts with strong oxidizers
Hazardous Decomposition Products: Sulfur dioxide, sodium oxide, potentially hydrogen sulfide if mixed with strong acids
Polymerization: Will not occur
Other Stability Issues: Contact with acids or moist conditions increases decomposition risk
Likely Exposure Routes: Inhalation, ingestion, skin and eye contact
Acute Toxicity: Oral LD50 (rat): >5000 mg/kg (very low toxicity in published studies)
Health Effects: May cause mild, reversible irritation of skin, eyes, or respiratory tract
Long-Term Exposure: No reliable evidence of chronic toxicity, carcinogenicity data lacking, generally not mutagenic or sensitizing
Medical Conditions Aggravated: Individuals with skin disorders may experience worsening symptoms after repeated contact
Symptoms of Overexposure: Nausea, headache, mild gastrointestinal upset if excessive amounts ingested
Aquatic Toxicity: LC50 (fish, 96 hr): generally above 1000 mg/L (low toxicity); high concentrations may cause oxygen depletion, harming aquatic life
Persistence and Degradability: Readily dissociates in water, breaks down in the environment by chemical and biological processes
Bioaccumulation: Unlikely due to high water solubility
Mobility in Soil: Highly mobile and soluble in water, leaches through soil easily, minimal absorption to soil particles
Other Environmental Hazards: Large spills may disrupt aquatic ecosystems by removing oxygen or interfering with natural redox cycles
Waste Disposal Methods: Collect waste in sealed containers, follow local, state, and federal guidelines for non-hazardous chemicals
Small Quantities: Dilute with water and dispose in sanitary drain if permitted by local authorities
Large Quantities: Contact licensed waste disposal contractor, prevent discharge into natural waters
Container Disposal: Rinse empty containers before recycling or disposal according to regulations
UN Number: Not regulated for road, rail, sea, or air transport
Proper Shipping Name: Sodium thiosulfate, non-hazardous
Hazard Class: Not classified
Packing Group: Not classified
Transport Labels: None required
Additional Notes: Protect from moisture during transport, avoid rough handling that could break containers
Global Inventory Status: Listed on major chemical inventories (TSCA, EINECS, DSL, ENCS, AICS, and others)
OSHA Status: Not classified as hazardous
EPA Regulations: Not listed as hazardous under RCRA or CERCLA
SARA Title III: Not listed as a reportable substance
Other Legislation: Compliant with EU REACH requirements, not subject to export controls
Labelling: No hazard symbols required under current GHS or European CLP standards
