Material Safety Data Sheet (MSDS) for Thiourea

Identification

Chemical Name: Thiourea
Synonyms: Thiocarbamide, Isothiourea
CAS Number: 62-56-6
Recommended Use: Laboratory chemical, photographic chemical, textile processing, chemical synthesis
Supplier Information: Contact supplied on purchase documentation; industrial chemical distributor or manufacturer
Emergency Phone Number: National Poison Control Center or local emergency services

Hazard Identification

GHS Classification: Acute toxicity—oral (Category 4), Skin sensitization (Category 1), Eye irritation (Category 2A)
Hazard Statements: Harmful if swallowed, may cause allergic skin reaction, causes serious eye irritation
Signal Word: Warning
Pictograms: Exclamation mark
Routes of Exposure: Inhalation, ingestion, skin, and eye contact
Potential Health Effects: Shortness of breath, nausea, skin rash, irritation of eyes and mucous membranes, possible carcinogen
Target Organs: Blood, liver, thyroid

Composition / Information on Ingredients

Chemical Identity: Thiourea
Chemical Formula: CH4N2S
Molecular Weight: 76.12 g/mol
Purity: Generally >99% Thiourea; low level impurities possible
Other Components: No significant non-hazardous substances present

First Aid Measures

Inhalation: Remove person to fresh air, keep at rest, seek medical attention if symptoms persist
Skin Contact: Remove contaminated clothing, wash skin with soap and water, get medical help if irritation develops
Eye Contact: Immediately flush eyes with plenty of water for at least 15 minutes, lift eyelids, obtain medical consultation
Ingestion: Rinse mouth with water, do not induce vomiting, get medical attention
Symptoms and Effects: Nausea, headache, burning sensation, redness, rash, respiratory discomfort
Special Notes to Physician: Symptomatic treatment, monitor for allergic reactions or systemic toxicity

Fire-Fighting Measures

Suitable Extinguishing Media: Water spray, alcohol-resistant foam, dry chemical, carbon dioxide
Unsuitable Media: Straight water jet in large volumes as accumulation could spread product
Fire Hazards: Product does not readily burn, but toxic decomposition fumes may be released, including oxides of nitrogen, sulfur oxides, hydrogen cyanide
Protective Equipment: Firefighters wear self-contained breathing apparatus, full protective gear
Explosion Risks: Dust-air mixtures might pose explosion risk in confined spaces

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel, ventilate area, avoid breathing dust, wear appropriate PPE like gloves, safety goggles, and particulate respirator
Environmental Protection: Prevent entry into drains, sewers, surface, and groundwater
Clean-Up Methods: Collect spillage with clean shovel into dry containers for disposal, wash area with water
Spill Reporting: Report major releases to local environmental authorities

Handling and Storage

Handling: Minimize dust generation, avoid skin and eye contact, use in well-ventilated areas, wash hands thoroughly after handling
Storage Conditions: Store in tightly closed containers, keep in a cool, dry, well-ventilated place away from incompatible materials
Incompatible Materials: Strong oxidizers, acids, nitrates
Special Rules: Avoid direct sunlight and heat sources, secure to avoid unauthorized use

Exposure Controls and Personal Protection

Occupational Exposure Limits: No OSHA PEL established; ACGIH TLV not specified
Engineering Controls: Use local exhaust ventilation or process enclosures as needed to control airborne dust
Personal Protective Equipment (PPE): Safety goggles or face shield, gloves resistant to chemicals, lab coat or coveralls
Respiratory Protection: Use NIOSH-approved particulate respirator for dusty conditions
Hygiene Measures: Remove contaminated clothing and wash before reuse, practice good industrial hygiene, avoid eating or drinking in chemical area

Physical and Chemical Properties

Appearance: White crystalline solid
Odor: Practically odorless
Odor Threshold: Not available
pH: 5.7 (10% solution in water)
Melting Point/Freezing Point: 176-178°C (decomposes)
Boiling Point: Decomposes without boiling
Solubility: Soluble in water, alcohol, slightly soluble in ether
Vapor Pressure: Negligible at ambient conditions
Density: 1.41 g/cm³
Viscosity: Not available
Partition Coefficient (Log Kow): -1.42
Evaporation Rate: Non-volatile
Flash Point: Not applicable
Auto-Ignition Temperature: Not self-igniting
Decomposition Temperature: Decomposes at approximately 180°C

Stability and Reactivity

Chemical Stability: Stable under normal conditions of use and storage
Reactive Incompatibility: Strong oxidizers may cause violent reactions; reacts with chlorates and nitrates
Hazardous Decomposition: Releases toxic fumes such as sulfur oxides, cyanides, nitrogen oxides upon decomposition
Polymerization: Not known to occur
Conditions to Avoid: Excessive heat, moisture, direct sunlight, incompatible chemicals

Toxicological Information

Oral Toxicity: LD50 (oral, rat): 175 mg/kg
Inhalation Toxicity: May cause respiratory irritation
Dermal Toxicity: May cause skin sensitization and allergic reactions
Carcinogenicity: IARC classifies as possible carcinogen (Group 2B); not regulated as carcinogen by OSHA
Mutagenicity: Positive in some genetic mutation tests
Reproductive Toxicity: Animal studies suggest potential reproductive effects
Long-Term Exposure: Possible thyroid effects, anemia, kidney and liver impairment reported in animal studies

Ecological Information

Aquatic Toxicity: Toxic to aquatic organisms (LC50 fish, 96h: 3-10 mg/L)
Persistence and Degradability: Not readily biodegradable; may persist in environment
Bioaccumulation: Low potential (low Log Kow), but build-up not expected
Mobility: Likely to leach to groundwater with water solubility
Other Effects: Possible alteration of aquatic ecosystems at high concentrations

Disposal Considerations

Waste Treatment Methods: Dispose by incineration or under supervision of environmental authority
Product Disposal: Avoid release to environment, dispose as hazardous waste following state/federal regulations
Contaminated Packaging: Rinse, neutralize, and recycle or dispose appropriately
Do Not: Discharge to drains, surface water, or groundwater

Transport Information

UN/ID Number: Not regulated as hazardous for transport under most international guidelines
Proper Shipping Name: Thiourea
Packaging: Use sealed chemical containers, labeled according to regulations
Transport Hazard Class: None assigned
Environmental Hazards: Not classified, but prevent spillage
Special Precautions: Protect from physical damage, moisture, and heat during transport

Regulatory Information

US TSCA Inventory: Listed
SARA 313: Not subject to reporting
OSHA Status: Hazardous
EU REACH: Registered substance; subject to restrictions on use
California Proposition 65: Listed as a chemical known to the State to cause cancer
WHMIS Classification (Canada): D2A—Very toxic (chronic), D2B—Toxic (other effects)
Other Regulations: Subject to environmental release reporting in some jurisdictions