2-Mercaptobenzothiazole (MBT) Material Safety Data Sheet (MSDS)

Identification

Product Name: 2-Mercaptobenzothiazole
Chemical Formula: C7H5NS2
Chemical Family: Benzothiazole derivatives
Other Names: MBT, 2-Benzothiazolethiol
CAS Number: 149-30-4
Recommended Uses: Vulcanization accelerator in rubber production, chemical intermediate, corrosion inhibitor
Supplier Information: Details such as manufacturer address, contact number, and emergency phone should be provided by the supplier
Synonyms: MBT, Mercaptobenzothiazole, 2-Benzothiazolethiol
Contact Point: Designated safety or technical support representative

Hazard Identification

Physical Hazards: May pose risk of dust explosion in fine powdered form; not classified as flammable
Health Hazards: Harmful if swallowed or inhaled, can cause allergic skin reaction and serious eye irritation, may cause respiratory irritation
Environmental Hazards: Toxic to aquatic life with long lasting effects, spills or uncontrolled releases can harm aquatic systems
GHS Classification: Skin sensitizer (Category 1), Eye irritation (Category 2), Acute aquatic toxicity (Category 1), Chronic aquatic toxicity (Category 1)
Signal Word: Warning
Hazard Statements: Harmful if swallowed, causes serious eye irritation, may cause allergic skin reaction, very toxic to aquatic life

Composition / Information on Ingredients

Chemical Name: 2-Mercaptobenzothiazole
Concentration: Typically >96% MBT by weight
Impurities: 2-Benzothiazolesulfonic acid (<2%), other trace impurities usually non-disclosed due to proprietary blends
Molecular Weight: 167.25 g/mol

First Aid Measures

Inhalation: Move person to fresh air, keep at rest, seek medical attention for irritation or discomfort
Skin Contact: Remove contaminated clothing, rinse skin immediately with plenty of water and soap; if rash develops, get medical advice
Eye Contact: Rinse eyes cautiously with water for 10–15 minutes; remove contact lenses if present and easy, seek prompt medical care
Ingestion: Rinse mouth with water, do not induce vomiting, seek medical attention; provide doctor with product information
Notes for Medical Personnel: Treat symptomatically; monitor for signs of allergic reaction or respiratory distress

Fire-Fighting Measures

Suitable Extinguishing Media: Water spray, carbon dioxide, dry chemical, or foam
Fire Hazards: Incomplete combustion may produce oxides of sulfur and nitrogen, benzothiazole compounds, carbon monoxide
Protective Equipment: Self-contained breathing apparatus and full protective clothing recommended
Other Information: Runoff from fire control or dilution water may pollute waterways

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel, wear protective gear including gloves, goggles, dust mask or respirator
Environmental Precautions: Prevent entry into waterways, sewers, and confined spaces
Cleanup Methods: Shovel or sweep up without creating dust, collect in suitable containers for disposal, clean affected area with water and detergent, ventilate area
Methods for Containment: Prevent further leakage or spillage if safe to do so

Handling and Storage

Handling: Avoid formation of dust, wear protective equipment, use only in well-ventilated areas, wash hands and equipment after use
Storage: Store in tightly closed containers in a dry, cool, well-ventilated place; keep away from acids, oxidizers, food and drink
Incompatible Materials: Acidic substances, strong oxidizing agents
Special Precautions: Use explosion-proof equipment where dust accumulation is possible

Exposure Controls and Personal Protection

Occupational Exposure Limits: ACGIH TLV (United States): 0.5 mg/m³ (inhalable fraction)
Engineering Controls: Local exhaust ventilation to maintain air levels below exposure limit
Personal Protective Equipment: Chemical-resistant gloves (nitrile, neoprene), safety glasses with side shields or goggles, dust mask or NIOSH-approved respirator, long sleeves, impervious footwear
Hygiene Measures: Wash hands before eating, drinking, or smoking; shower after work shift if significant exposure suspected

Physical and Chemical Properties

Appearance: Pale yellow to off-white crystalline powder
Odor: Slight mercaptan (sulfurous) odor
Odor Threshold: Not established
pH (1% Solution): 5.5–7.0
Melting Point: 173–179°C
Boiling Point: Decomposes before boiling
Flash Point: Not applicable (decomposes)
Vapor Pressure: Practically none at 20°C
Solubility: Poor in water (<10 mg/L at 20°C), soluble in alcohol, acetone, benzene
Partition Coefficient (log Kow): 2.42
Decomposition Temperature: >150°C
Auto-ignition Temperature: Not determined

Stability and Reactivity

Chemical Stability: Stable under normal conditions, moisture and heat may cause slow decomposition
Reactivity: Reacts with strong acids or oxidizers, may generate hazardous decomposition products
Conditions to Avoid: Heat, flame, sources of ignition, acids, oxidizers
Hazardous Decomposition Products: Sulfur oxides, nitrogen oxides, carbon monoxide, benzothiazole, thiols
Polymerization: Not expected under normal conditions

Toxicological Information

Acute Toxicity: Oral LD₅₀ (rat): approx. 700–3,000 mg/kg
Inhalation: Dust may cause respiratory tract irritation
Skin Contact: Sensitization and contact dermatitis in susceptible individuals
Eye Contact: Serious eye irritation can occur
Chronic Exposure: Prolonged or repeated exposure may result in liver and kidney effects, skin sensitization
Carcinogenicity: IARC: Not classifiable as to its carcinogenicity (Group 3), not listed as a known human carcinogen by NTP or OSHA
Mutagenicity: Mixed results in genotoxicity studies, not conclusively proven
Other Effects: Asthma-like symptoms reported in sensitive workers

Ecological Information

Ecotoxicity: Highly toxic to aquatic organisms; 96-hour LC₅₀ for fish (O. mykiss): 0.71 mg/L, Daphnia 48-hour EC₅₀: 1.9 mg/L
Persistence and Degradability: Moderately persistent, does not readily biodegrade in water; slow degradation in soil
Bioaccumulation: Potential for bioaccumulation exists (log Kow: 2.42)
Mobility in Soil: Limited due to low water solubility, may bind to soil and sediment
Other Adverse Effects: May disrupt aquatic microbial life, chronic effects in aquatic invertebrates

Disposal Considerations

Waste Treatment Methods: Dispose according to local, regional, national, and international requirements for hazardous waste
Product Disposal: Do not discharge to drains or watercourses, incinerate only in properly equipped facility
Contaminated Packaging: Send for specialized treatment or incineration, containers should not be reused
Waste Codes: Assign in accordance with applicable regulations

Transport Information

UN Number: Not regulated for most forms of ground or air shipment
Transport Hazard Class: Not classified as a dangerous good per ADR, IATA, IMDG
Packing Group: Not applicable
Special Precautions: Avoid spillage in transit, secure tightly
Environmental Hazards: Marine pollutant if released in bulk quantities
Transport Labels: Not required for most shipments, caution advised with large quantities

Regulatory Information

OSHA: Regulated as hazardous under Hazard Communication Standard
TSCA: Listed on United States TSCA Inventory
REACH (EU): Registered substance, subject to restrictions for use in consumer products
SARA Title III: Subject to certain reporting requirements under Section 313
California Proposition 65: Not listed
Canada DSL: Listed
Other Applicable Regulations: Superfund Amendments, Clean Water Act for hazardous substance release, workplace safety standards in major markets