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Chemical Name: 2-Mercapto-5-Methoxybenzimidazole
Synonyms: 5-Methoxy-2-mercaptobenzimidazole, Methoxymercaptobenzimidazole
Molecular Formula: C8H8N2OS
CAS Number: 37052-78-1
Recommended Use: Laboratory reagent, intermediate for pharmaceuticals and specialty chemicals
Manufacturer Details: Contact information including address, telephone, and emergency response number should be specified on the company label and included with each package.
GHS Classification: Skin Irritation: Category 2, Eye Irritation: Category 2A, Acute Toxicity Oral: Category 4, Aquatic Toxicity: Category 3
Signal Word: Warning
Hazard Statements: Causes skin irritation, Causes serious eye irritation, Harmful if swallowed, Harmful to aquatic life
Pictograms: Exclamation mark
Precautionary Statements: Avoid contact with eyes, skin, and clothing. Do not breathe dust. Wash hands thoroughly after handling. Avoid release to the environment.
Chemical Identity: 2-Mercapto-5-Methoxybenzimidazole
Purity: Typically >98% by weight
Impurities: Trace amounts of related benzimidazoles under 2%
Hazardous Components: No major hazardous impurities identified in quality controlled production lots.
Inhalation: Move affected person to fresh air. Seek medical attention if symptoms persist, such as coughing, trouble breathing.
Skin Contact: Remove contaminated clothing, rinse skin with plenty of water and mild soap. If irritation develops, see a doctor.
Eye Contact: Rinse cautiously with water for at least 15 minutes, keeping eyelids open. Remove contact lenses if present and easy to do. Continue rinsing. Seek medical attention if irritation remains.
Ingestion: Rinse mouth with water, do not induce vomiting unless directed by medical personnel. Get prompt medical advice if symptoms occur.
Suitable Extinguishing Media: Water spray, foam, dry chemical powder, carbon dioxide
Specific Hazards: Harmful fumes, including oxides of nitrogen, sulfur oxides, carbon monoxide and carbon dioxide, may be released.
Protective Equipment: Firefighters should use self-contained breathing apparatus and protective clothing.
Other Instructions: Avoid inhaling combustion products, keep containers cool with water spray if exposed to fire.
Personal Precautions: Wear chemical resistant gloves, safety goggles, and disposable dust mask or respirator. Remove all sources of ignition.
Environmental Precautions: Prevent further spillage or leakage if safe. Avoid discharge into the environment, especially drains or surface waters.
Cleanup Methods: Sweep up using non-sparking tools and place in suitable, clearly marked containers for disposal. Ventilate the area and wash spill site after material removal.
Handling: Use in a well-ventilated area. Minimize dust generation and accumulation. Avoid unnecessary exposure and use appropriate protective equipment.
Storage Conditions: Store in tightly sealed containers at room temperature, away from light, heat sources, acids, and oxidizing materials. Ensure secondary containment and clear labelling.
Incompatibilities: Strong oxidizers, strong acids, and acid chlorides. Store separately from food or beverages.
Engineering Controls: Apply local exhaust ventilation or use fume hoods. Eyewash stations and safety showers should be accessible.
Personal Protective Equipment: Wear splash-resistant safety goggles, chemical-resistant gloves such as nitrile, laboratory coat or apron.
Respiratory Protection: Dust mask or respirator meeting standards if dust is generated above recommended exposure limits.
Hygienic Practices: Wash hands thoroughly after handling. Do not eat, drink, or smoke when using this material.
Appearance: Off-white to pale yellow crystalline powder
Odor: Faint, characteristic mercaptan-like odor
Melting Point: 183–187°C
Boiling Point: Decomposes before boiling
Solubility: Slightly soluble in water, freely soluble in alcohols and acetone
Density: 1.35 g/cm3 (approximate)
pH: No data available in aqueous solution
Vapor Pressure: Essentially negligible at room temperature
Partition Coefficient: Log P estimated at 1.7–2.0
Other Properties: Not volatile at standard temperature and pressure, sensitive to strong oxidizers.
Stability: Stable at standard temperature and pressure under recommended storage conditions
Incompatible Materials: Strong oxidizing agents, acids, acid chlorides
Decomposition Products: Emission of nitrogen oxides, sulfur oxides, and carbon oxides on thermal decomposition
Polymerization: No hazardous polymerization reported
Conditions to Avoid: Exposure to excessive heat, direct sunlight, high humidity, contact with incompatible materials
Routes of Exposure: Inhalation, ingestion, skin, and eye contact
Acute Effects: May cause irritation on contact with eyes or skin; ingestion or inhalation of dust may cause headache, nausea, or discomfort.
Chronic Effects: No chronic toxicity data available, repeated exposure not studied in humans.
Toxicity Values: Estimated oral LD50 (rat): ~300–500 mg/kg (moderate toxicity range)
Carcinogenicity: No components classified as carcinogenic by OSHA, IARC, NTP, or ACGIH.
Other Information: Not known to be mutagenic or teratogenic based on available data; lacks long-term animal studies.
Aquatic Toxicity: Harmful to aquatic organisms, possible long-term adverse effects in the aquatic environment
Persistence and Degradability: Not readily biodegradable; slow breakdown in soil and water reported
Bioaccumulation Potential: Moderate, based on calculated partition coefficient
Mobility in Soil: Low; tends to bind to organic matter
Other Environmental Info: Avoid release to waterways. Inform the authorities in case of significant spillage.
General Disposal: Keep chemical waste in tightly closed, clearly labeled containers. Comply with local and national regulations.
Incineration: Preferred method under controlled conditions at authorized chemical waste facilities.
Contaminated Packaging: Rinse containers, then treat as hazardous waste; follow legal requirements for recycling or disposal.
Special Note: Do not release product or rinsate into drains, surface water, or soil. Dispose via licensed waste management company.
UN Number: Not classified as hazardous for transport under most global regulations
Proper Shipping Name: Not regulated; ship as laboratory chemical under general safety rules
Hazard Class: Not applicable
Packaging Group: Not assigned
Special Precautions: Ship in sealed, labelled containers away from food and incompatible substances
US Regulations: Not listed as hazardous under SARA Title III, Section 313, or the Clean Air Act; may require notification under TSCA inventory
EU Regulations: Classified as hazardous under Regulation (EC) No 1272/2008 (CLP); safety phrases required on packaging
Labels: Hazard pictograms and relevant warning sentences included on all packaging
Other Regulations: Handle according to standard laboratory chemical safety protocols; ensure staff training on risks and safe practices
