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Product Name: Sodium Metabisulfite
Chemical Formula: Na2S2O5
Synonyms: Disodium disulfite, Sodium pyrosulfite
CAS Number: 7681-57-4
Supplier Details: Company address, emergency phone number, and contact information for manufacturer or distributor.
Recommended Use: Food preservative, water treatment, bleaching agent, chemical production.
Restrictions on Use: None recognized beyond those required by local regulations as determined by hazardous nature.
Classification: Acute Toxicity (Oral), Eye Irritation, Skin Sensitization
Label Elements: Pictograms for corrosive, irritation, skull and crossbones for acute toxicity
Signal Word: Warning
Hazard Statements: May cause respiratory, skin, and eye irritation; Harmful if swallowed; May trigger asthmatic symptoms; May cause allergic skin reaction
Precautionary Statements: Avoid breathing dust; Wash exposed areas thoroughly after handling; Use only outdoors or in well-ventilated spaces; Wear protective gloves, eye and face protection
Potential Health Effects: Eyes can redden and water, skin can develop hives or eczema, inhalation can cause coughing, chest tightness, aggravated asthma, and gastrointestinal distress if ingested.
Chemical Name: Sodium Metabisulfite
Proportion: Between 95% and 100% pure
Impurities: Trace sodium sulfite, sodium sulfate, water
Other Components: None with health risks estimated above ingredient on a weight basis at compliance thresholds.
Molecular Weight: 190.1 g/mol
Inhalation: Move affected individual to fresh air, loosen clothing, keep at rest, seek medical help if respiratory distress persists—especially for people with asthma
Skin Contact: Remove contaminated clothing, rinse skin with soap and moderate to large amounts of water, seek medical attention if irritation forms or persists
Eye Contact: Flush eyes gently with water for 15 minutes while holding eyelids apart; get medical assistance if irritation continues
Ingestion: Rinse mouth, do not induce vomiting, drink water if conscious, call poison center or physician quickly
Most Important Symptoms: Shortness of breath, skin itching, red or blistered eyes, stomach pain, nausea
Special Notes for Doctors: Treat symptomatically, identify possible allergic or asthmatic reactions tied to sulfite sensitivity.
Suitable Extinguishing Media: Dry chemical, carbon dioxide, water spray, alcohol-resistant foam
Unsuitable Extinguishing Media: Avoid using strong water jets; may spread material
Specific Hazards: Decomposes when heated above 150°C, releasing toxic sulfur dioxide gas
Protective Equipment: Self-contained breathing apparatus, full protective clothing
Firefighting Precautions: Approach from upwind to avoid toxic vapors, remove containers from fire zone when safe, cool exposed containers with water spray
Hazardous Combustion Products: Sulfur oxides, sodium oxide
Special Procedures: Prevent run-off; contaminated firefighting runoff could damage the environment.
Personal Precautions: Evacuate area, use respirators and protective gear, keep unprotected people away
Environmental Precautions: Avoid spills reaching watercourses, storm drains, or soil
Containment: Cover with inert material like dry sand or earth, scoop into containers
Cleanup Methods: Sweep or shovel residues for disposal under regulatory controls; avoid dust formation, use damp sweeping
Spill Reporting: Notify authorities as mandated by local regulations and company policy.
Precautions in Handling: Prevent inhalation, skin, and eye contact; minimize dust generation; handle only with adequate ventilation; wash hands and exposed skin after use; store separately from oxidizers, acids, and moisture
Storage Conditions: Seal containers tightly in cool, dry, ventilated location, away from kitchens, direct sunlight, or acidic materials
Incompatible Materials: Strong acids, oxidizing agents, humid environments
Storage Containers: Use only containers and equipment with corrosion-resistant linings
Other Notes: Check shelf life regularly; label all containers clearly.
Occupational Exposure Limits: ACGIH TLV: 5 mg/m³ (as SO2), OSHA PEL: 5 mg/m³
Engineering Controls: Local exhaust ventilation, isolation, and dust collection systems
Personal Protection Equipment: Chemical-resistant gloves, splash-proof goggles, NIOSH-approved respirator for dust/fumes above limits, long-sleeved clothing
Hygiene Measures: Shower and change clothing after work, do not eat or smoke in work area
Monitoring Methods: Regular airborne dust measurements in the workplace, onsite emergency eyewashes and showers.
Appearance: White to yellowish crystalline powder or solid
Odor: Pungent, sulfurous smell
Odor Threshold: 1 mg/m³ (noticeable by most)
pH: 3.5–5.0 (1% solution)
Melting Point: Decomposes above 150°C
Boiling Point: Not applicable
Flash Point: Not flammable
Flammability: Not combustible but supports burning by releasing SO2 gas
Solubility: Soluble in water, slightly soluble in ethanol
Vapor Pressure: Not measurable at room temperature
Density: Approximately 1.4 g/cm³
Partition Coefficient (n-octanol/water): Not determined
Other Properties: Releases sulfur dioxide on contact with hot water or acids.
Chemical Stability: Remains stable under dry, cool, and well-ventilated conditions
Possibility of Hazardous Reactions: Hazardous gases like sulfur dioxide may evolve on contact with acids or when heated
Conditions to Avoid: Humid environments, exposure to acids, excessive heat
Incompatible Materials: Acids, oxidizers, aluminum, magnesium, water
Hazardous Decomposition Products: Sulfur dioxide, sodium oxides, potential irritating sulfur compounds
Polymerization: No known hazardous polymerization.
Acute Toxicity: Oral LD50 for rats: Approximately 1130 mg/kg; Harmful if ingested or inhaled
Skin Corrosion/Irritation: Can cause dermatitis by repeated or prolonged contact
Eye Damage/Irritation: Causes serious eye irritation, potential temporary visual disturbance
Respiratory Sensitization: Sulfite-sensitive individuals may suffer asthmatic symptoms, wheezing, pulmonary distress
Skin Sensitization: May provoke allergic response after repeated contact
Chronic Effects: Long-term exposure may aggravate existing asthma or respiratory illnesses
Carcinogenicity: Not listed by IARC or NTP as a carcinogen
Other Health Data: Certain populations, especially asthmatics or allergic individuals, face extra health risks.
Ecotoxicity: Very toxic to aquatic life in large concentrations; fish, daphnia, and aquatic plants can suffer oxygen deprivation
Persistence and Degradability: Tends to break down in water and soil but sudden large releases disrupt environments
Bioaccumulative Potential: Low, sodium and sulfur components remain largely water-soluble
Mobility: High in soil and water; entry to waterways should be minimized
Other Adverse Effects: Oxidation to sulfate in environment, acidification of water bodies possible
Regulatory Classification: Usually labeled hazardous to aquatic systems as per global hazard communication standards.
Waste Treatment Methods: Dispose according to local, national, and regional legislation for hazardous waste
Disposal Containers: Use sealed, labeled, corrosion-resistant containers
Precautions for Disposal: Prevent leaks, accumulation, and releases into drains, sewers, or the environment
Safe Disposal Procedures: Neutralize with alkaline and dilute sodium hypochlorite before disposal when feasible; request licensed hazardous waste handler to collect
Packaging Disposal: Contaminated packaging needs to be incinerated or landfilled per approved facility instructions.
UN Number: UN 3077
Proper Shipping Name: Environmentally hazardous substance, solid, n.o.s. (Sodium Metabisulfite)
Transport Hazard Class: Class 9 (Miscellaneous Dangerous Substances)
Packing Group: III (minor danger)
Marine Pollutant: Yes
Special Precautions for Transport: Secure containers during transit, avoid hauling with acids or oxidizers, prevent moisture contact during transportation
Regulatory Codes: Consult IMDG, ADR, IATA, and US DOT guidelines before shipping internationally or by air/sea.
US Regulations: SARA 313, TSCA (listed chemical); CERCLA reportable quantity: not assigned
EU Regulations: Listed under REACH, hazard symbol ‘Xi’ (irritant) and ‘N’ (dangerous for environment); Safety phrases apply
Workplace Controls: OSHA and ACGIH specify workplace dust control and monitoring
Labeling Requirements: Hazard pictograms, warning phrases, contact details of supplier
International Inventories: Included in national chemical inventories for Australia, Canada, Japan, Korea, China, Philippines
Other Notes: Product use and labeling subject to routine updates as regulations evolve and research adds new risk documentation.
