Material Safety Data Sheet – Methyl Tin Mercaptide

Identification

Product Name: Methyl Tin Mercaptide
Chemical Formula: C9H20O2S4Sn
Synonyms: Methyltin thioglycolate, Methyltin mercaptide stabilizer
CAS Number: 57583-34-3
Manufacturer: Contact details available on label
Recommended Use: PVC stabilization, plastics processing, heat stabilizer
Emergency Contact Number: Chemtrec or national poison control center

Hazard Identification

Classification: Acute toxicity – oral, Category 4; Skin irritation, Category 2; Eye irritation, Category 2; Specific target organ toxicity, single exposure, Category 3
Pictograms: Exclamation mark, health hazard
Signal Word: Warning
Hazard Statements: Harmful if swallowed; Causes skin irritation; Causes serious eye irritation; May cause respiratory irritation
Precautionary Statements: Avoid breathing dust or vapors; Wash thoroughly after handling; Use only outdoors or in a well-ventilated area; Wear protective gloves, clothing, and eye protection
Routes of Exposure: Inhalation, ingestion, skin, and eye contact
Target Organs: Liver, kidneys, central nervous system, respiratory system

Composition / Information on Ingredients

Chemical Identity: Methyl Tin Mercaptide
CAS Number: 57583-34-3
Concentration: 95–100%
Impurities: Trace organic solvents or stabilizers below 2%
Tin Content: 18–23% by weight
Molecular Weight: Approx. 409.18 g/mol

First Aid Measures

Inhalation: Move victim to fresh air; if breathing is difficult, administer oxygen and seek medical help
Skin Contact: Remove contaminated clothing; wash affected area thoroughly with water and soap; medical attention if irritation persists
Eye Contact: Rinse immediately with plenty of water for at least 15 minutes, keeping eyelids open; seek prompt medical assistance
Ingestion: Do not induce vomiting; rinse mouth with water; give victim water to drink if conscious; seek immediate medical attention
Most Important Symptoms: Redness, swelling, dizziness, headache, nausea
Note to Physicians: Treat symptomatically and provide supportive measures as needed

Fire-Fighting Measures

Suitable Extinguishing Media: Carbon dioxide, dry chemical powder, alcohol-resistant foam
Unsuitable Extinguishing Media: Direct water jets may spread the material
Specific Hazards: Combustion produces toxic gases such as tin oxides, sulfur oxides, carbon monoxide and dioxide
Protective Equipment: Self-contained breathing apparatus and full chemical protection suit
Special Precautions: Move containers away from fire if safe; keep run-off water out of sewers; avoid inhalation of fumes

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel; avoid contact with skin, eyes, and clothing; ventilate area
Protective Equipment: Wear gloves, goggles, respirators, chemical-resistant clothing
Methods for Clean-Up: Absorb with non-combustible, inert material (vermiculite, sand); place in chemical waste container for proper disposal
Environmental Precautions: Prevent entry to soil, sewers, waterways; notify authorities if large amounts escape
Decontamination: Clean spill area thoroughly with water and detergent after initial clean-up

Handling and Storage

Handling: Use only with adequate ventilation; avoid generating mist or vapor; do not eat, drink or smoke during handling; wash hands after use; keep containers tightly closed
Storage: Store in original, tightly-sealed containers away from moisture, direct sunlight, heat, acids, and oxidizing agents; keep in a cool, dry, well-ventilated area
Storage Incompatibilities: Avoid contact with strong oxidizers, acids, alkalis
Storage Temperature: Keep below 30°C (86°F)
Packaging Materials: Compatible with high-density polyethylene, glass, or stainless steel containers

Exposure Controls and Personal Protection

Occupational Exposure Limits: No OSHA PEL; ACGIH TLV for organotin compounds (as Sn): 0.1 mg/m³ TWA
Engineering Controls: Use local exhaust ventilation and enclose processes to minimize exposure
Personal Protection: Safety goggles, chemical-resistant gloves (nitrile or butyl rubber), protective clothing, face shield if splashing likely
Respiratory Protection: Use NIOSH-approved respirator in case of inadequate ventilation or airborne concentration above exposure limit
Hygiene Measures: Remove and wash contaminated clothing before reuse; wash hands after handling

Physical and Chemical Properties

Appearance: Clear to pale yellow liquid
Odor: Mild mercaptan-like
Odor Threshold: Low, but varies by formulation
pH: Not applicable
Boiling Point: >200°C (>392°F)
Melting Point: Below -15°C (5°F)
Flash Point: 123°C (254°F) (closed cup)
Flammability: Not classified as flammable
Vapor Pressure: Very low at room temperature
Solubility: Negligible in water; soluble in organic solvents
Relative Density: 1.18–1.23 g/cm³
Viscosity: 110–130 mPa•s at 25°C
Partition Coefficient (n-octanol/water): Not determined
Decomposition Temperature: >200°C
Evaporation Rate: Not available

Stability and Reactivity

Chemical Stability: Stable under normal temperatures and pressures
Conditions to Avoid: Elevated heat, open flames, strong sunlight, exposure to air or moisture
Incompatible Materials: Strong acids, bases, oxidizing agents
Hazardous Decomposition Products: Tin oxides, sulfur oxides, carbon oxides, methyl compounds
Hazardous Reactions: Can react with acids or oxidizers to form toxic gases or exothermic reactions

Toxicological Information

Acute Toxicity: Oral LD50 (rat): 300–2000 mg/kg; skin LD50: >2000 mg/kg; inhalation LC50: not available
Skin Irritation: Causes irritation, redness
Eye Irritation: Severe eye irritation, possible damage
Respiratory Irritation: May cause coughing, shortness of breath, sore throat
Sensitization: Not a known sensitizer
Chronic Effects: Long-term exposure may affect liver, kidneys, neurological function
Carcinogenicity: Not listed by IARC, NTP, OSHA
Mutagenicity: No conclusive evidence
Reproductive Toxicity: Limited evidence in animal studies; more research needed

Ecological Information

Ecotoxicity: Harmful to aquatic organisms; may cause long-term adverse effects in the aquatic environment
Aquatic Toxicity: Fish LC50 (96 h): 1–10 mg/L; Daphnia EC50 (48 h): 1–10 mg/L
Persistence and Degradability: No significant biodegradation; may persist in environment
Bioaccumulative Potential: Expected to be low based on molecular size
Mobility in Soil: Low mobility; tends to adsorb to soil particles
Other Effects: Avoid release into surface water or soil

Disposal Considerations

Waste Disposal: Dispose of as hazardous waste in compliance with local, regional, and national regulations; do not pour into drains or environment
Contaminated Packaging: Empty containers and residues should be treated as hazardous; triple rinse before recycling or disposal
Recommended Disposal Methods: Incineration at a licensed facility
Additional Measures: Contact waste disposal contractor; keep disposal documentation to show compliance

Transport Information

UN Number: Not classified as dangerous goods under UN, IMDG, IATA
Proper Shipping Name: Methyl Tin Mercaptide
Transport Hazard Class: Not regulated
Packing Group: Not assigned
Environmental Hazards: Harmful to aquatic environment, mark package and documents accordingly
Transport Precautions: Prevent container damage; secure load properly during transport; avoid exposure to moisture or high temperatures

Regulatory Information

TSCA Inventory: Listed
REACH Status: Registered or pre-registered with European authorities
OSHA Hazards: Irritant, harmful by ingestion
SARA Title III: Not subject to reporting
California Proposition 65: Not listed as a chemical known to cause cancer or reproductive toxicity
WHMIS (Canada): Classified as hazardous, workplace label required
Other Regulations: Subject to workplace safety, environmental release, and chemical control regulations as applicable in national and regional jurisdictions
Label Elements: Emergency telephone number, hazard symbols, precaution statements, supplier contact details, disposal information must be present on product label