Material Safety Data Sheet for Ethyl Mercaptan (EM)

Identification

Chemical Name: Ethyl Mercaptan
Synonyms: Ethanethiol, Thioethanol, EtSH
Molecular Formula: C2H6S
Molecular Weight: 62.13 g/mol
CAS Number: 75-08-1
Recommended Use: Gas odorant for leak detection, chemical intermediate
Supplier Information: Relevant supplier or manufacturer contact details
Emergency Telephone: Poison control or national chemical emergency number

Hazard Identification

Classification: Flammable liquid (Category 2), Acute toxicity (Oral Category 3, Inhalation Category 3, Dermal Category 3), Skin irritation (Category 2), Eye irritation (Category 2A)
Pictograms: Flame, Skull and Crossbones, Exclamation Mark
Signal Word: Danger
Hazard Statements: Highly flammable liquid and vapor, toxic if inhaled, fatal if swallowed or absorbed through skin, causes skin and serious eye irritation, may cause respiratory irritation
Precautionary Statements: Avoid release to the environment, keep away from heat, sparks, open flames, and hot surfaces, use personal protective equipment, wash skin thoroughly after handling, do not eat, drink, or smoke while using product
Routes of Entry: Inhalation, skin, ingestion, eyes
Target Organs: Central nervous system, respiratory system, skin, eyes

Composition / Information on Ingredients

Substance: Ethyl Mercaptan
Concentration: ≥99%
Impurities: Trace amounts of other volatile organic sulfur compounds, none at levels that alter hazard classification

First Aid Measures

Inhalation: Remove to fresh air, provide oxygen if breathing is difficult, seek medical attention immediately if symptoms persist
Skin Contact: Remove contaminated clothing, wash skin thoroughly with soap and water, get medical attention if irritation develops
Eye Contact: Rinse immediately with plenty of water for at least 15 minutes, remove contact lenses if present, seek medical help right away
Ingestion: Do not induce vomiting, rinse mouth with water, call poison control center or doctor immediately, never give anything by mouth to an unconscious person
Most Important Symptoms: Severe irritation, headache, dizziness, nausea, respiratory distress, unconsciousness

Fire-Fighting Measures

Suitable Extinguishing Media: Foam, dry chemical, carbon dioxide, water spray
Unsuitable Extinguishing Media: Direct water jet increases vapor spread
Specific Hazards: Extremely flammable vapors form explosive mixtures with air, combustion releases toxic gases including sulfur oxides and carbon monoxide
Protective Equipment: Firefighters should wear self-contained breathing apparatus and full protective clothing
Special Procedures: Fight fire from upwind, cool exposed containers with water spray, evacuate area, avoid inhalation of fumes

Accidental Release Measures

Personal Precautions: Evacuate area, ventilate closed spaces, eliminate ignition sources, keep unprotected people away, use non-sparking tools
Protective Equipment: Chemical-resistant gloves, goggles, respiratory protection (SCBA if concentrations are high)
Spill Cleanup: Contain liquid with inert absorbent material, collect material in suitable chemical waste containers, do not wash into sewer, dispose according to regulations
Environmental Precautions: Prevent entry into waterways, drains and sewers, notify authorities if large quantities enter the environment

Handling and Storage

Handling: Use only in well-ventilated areas, ground/bond containers and equipment, avoid contact with skin, eyes and clothing, prevent the buildup of static electricity, keep away from sparks, open flames and hot surfaces, do not breathe vapors or mist
Storage: Store locked up in tightly closed containers, in cool, dry, well-ventilated areas away from heat sources and incompatible substances such as oxidizers and acids, dedicated vented metal drums or pressure-rated vessels recommended, post warning signs around storage area

Exposure Controls and Personal Protection

Occupational Exposure Limits: OSHA PEL: 0.5 ppm (1 mg/m³) TWA, ACGIH TLV: 0.5 ppm
Engineering Controls: Use process enclosures, local exhaust and general ventilation, explosion-proof equipment, gas detection systems
Personal Protective Equipment (PPE): Chemical splash goggles or face shield, flame-resistant clothing, chemical-resistant PVC or nitrile gloves, full-coverage apron, positive pressure respirator in high concentrations
Hygiene Measures: Wash hands before breaks, after handling, and at end of work, remove contaminated clothing and equipment before entering eating areas

Physical and Chemical Properties

Appearance: Colorless or light yellow liquid
Odor: Pungent, skunk-like
Odor Threshold: Extremely low (detectable at 0.00019 ppm)
pH: Not applicable
Melting Point: -146°C
Boiling Point: 35°C
Flash Point: -45°C (closed cup)
Evaporation Rate: Rapid
Flammability: Flammable liquid and vapor
Lower Explosion Limit: 3.3% (v/v)
Upper Explosion Limit: 15.0% (v/v)
Vapor Pressure: 442 mm Hg at 20°C
Vapor Density: 2.1 (air = 1)
Relative Density: 0.84 g/cm³ (at 20°C)
Solubility: Slightly soluble in water, miscible with most organic solvents
Partition Coefficient (n-octanol/water): 0.91
Decomposition Temperature: Above 270°C
Viscosity: Not available

Stability and Reactivity

Chemical Stability: Stable under recommended storage and handling, highly reactive with oxidizers
Hazardous Reactions: May react violently with acids, halogens, strong oxidizers
Conditions to Avoid: Heat, flame, sparks, strong oxidizing agents, acids, exposure to light
Hazardous Decomposition Products: Sulfur oxides, ethylene, hydrogen sulfide, carbon monoxide and carbon dioxide

Toxicological Information

Acute Toxicity: LD50 (oral, rat): 682 mg/kg, LC50 (inhalation, rat, 4h): 442ppm
Skin Corrosion/Irritation: Causes redness and severe irritation
Serious Eye Damage/Irritation: Severe eye irritant, may cause watering, redness, pain
Respiratory Sensitization: Can irritate nose, throat, lungs, coughing and difficulty breathing possible
Germ Cell Mutagenicity: No evidence available
Carcinogenicity: Not listed as carcinogenic by IARC, ACGIH, NTP or OSHA
Reproductive Toxicity: No evidence for reproductive effects
Specific Target Organ Toxicity (Single Exposure): Dizziness, headache, confusion, nausea, CNS depression
Specific Target Organ Toxicity (Repeated Exposure): Not well established
Aspiration Hazard: Harmful if aspirated into lungs

Ecological Information

Ecotoxicity: Toxic to aquatic life based on acute aquatic toxicity studies; LC50 (Fish, 96 h): 12 mg/L
Persistence and Degradability: Readily biodegradable in air, slower in water and soil
Bioaccumulative Potential: Low, log Kow: 0.91
Mobility in Soil: Moderate, may volatilize from moist soil
Other Adverse Effects: Contributes to acid rain and odor pollution; high levels may disrupt ecosystems by sudden oxygen depletion

Disposal Considerations

Methods of Disposal: Incinerate under controlled conditions in licensed facility, dispose of contaminated packaging by incineration or landfill in compliance with local, regional and national laws
Disposal Containers: Use strong, sealed chemical waste containers, store for pickup by licensed waste hauler
Precautions: Do not discharge to surface water or sewers, avoid environmental contamination

Transport Information

UN Number: UN2363
UN Proper Shipping Name: Ethyl Mercaptan
Transport Hazard Class: 3 (Flammable Liquid), 6.1 (Toxic Substance)
Packing Group: I
Labels: Flammable Liquid, Toxic
Special Precautions: Emergency response guide 131, use explosion-proof transport and loading equipment, ensure containers are tightly sealed and properly labeled
Marine Pollutant: No
Environmental Hazards: Not classified as marine pollutant, avoid spills during transfer

Regulatory Information

OSHA: Listed as hazardous, subject to OSHA Process Safety Management
TSCA: Listed in Toxic Substances Control Act Inventory
SARA Title III: Immediate (acute) health hazard, fire hazard
RCRA: Not listed as hazardous waste, may meet definition based on concentration and mixture
WHMIS (Canada): B2: Flammable Liquid, D1A: Immediate and Serious Toxic Effects
EU Regulation: Classified as Flammable, Toxic, Irritant under CLP Regulation (EC) No 1272/2008
Other: Subject to local, regional and international controls on storage, handling and emission; ensure users comply with all applicable requirements