Material Safety Data Sheet (MSDS) – Isobutyl Mercaptan

Identification

Product Name: Isobutyl Mercaptan
Chemical Formula: C4H10S
Synonyms: 2-Methyl-1-propanethiol, tert-Butyl mercaptan
CAS Number: 513-44-0
Recommended Use: Used in fragrances, gas odorants, intermediate in organic synthesis
Supplier Identification: Manufacturer and distributer contact with address, email, and emergency phone line
UN Number: UN 2347
Emergency Overview: Strong, offensive odor; flammable, toxic upon inhalation and skin contact, dangerous to aquatic life

Hazard Identification

Hazard Classification: Flammable liquid (Category 3), Acute toxicity inhalation (Category 4), Serious eye irritation (Category 2A), Chronic aquatic toxicity (Category 2)
Signal Word: Danger
Hazard Statements: Flammable liquid and vapor, causes skin and eye irritation, harmful if swallowed or inhaled, toxic to aquatic life with long lasting effects
Precautionary Statements: Keep away from open flames, use explosion-proof equipment, avoid breathing vapors, wash hands thoroughly after handling, wear protective gloves and eye protection
Symptoms of Exposure: Headache, nausea, dizziness, respiratory discomfort, skin and eye redness or burning, potential allergic skin reactions

Composition / Information on Ingredients

Chemical Identity: Isobutyl Mercaptan
Content: 98–100% by weight
Impurities: Trace levels of higher and lower mercaptans, possible sulfides
Other Components: No additives or stabilizers documented

First Aid Measures

Inhalation: Remove to fresh air; seek medical attention if breathing problems develop; administer oxygen if necessary; avoid direct mouth-to-mouth resuscitation
Skin Contact: Wash with plenty of soap and water, remove contaminated clothing, seek medical attention if irritation persists, do not use solvents
Eye Contact: Rinse under running water for at least 15 minutes; remove contact lenses if present and easy to do; seek immediate medical advice
Ingestion: Do not induce vomiting, rinse mouth, provide water to drink if conscious; seek medical attention promptly
Notes for Physicians: Treat symptomatically and consider risk of chemical pneumonitis

Fire-Fighting Measures

Suitable Extinguishing Media: Foam, dry chemical, carbon dioxide, do not use water jet directly
Special Hazards: Vapors may form explosive mixtures with air, combustion generates toxic gases including sulfur oxides and hydrogen sulfide, containers may explode if heated
Protective Equipment for Firefighters: Full protective clothing, self-contained breathing apparatus, stay upwind, avoid contact with burning material
Specific Procedures: Cool containers with water spray, remove combustibles from area, prevent runoff from fire control from entering waterways

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel, avoid inhalation and skin contact, ventilate area, wear appropriate protective equipment
Environmental Precautions: Prevent entry into sewers, drains, and waterways, inform local authorities in case of significant spillage
Containment and Clean-up Methods: Absorb spill with inert material (sand, earth), collect in sealable containers for disposal, ventilate area, avoid generating vapor, wash spill site after material pickup

Handling and Storage

Safe Handling Guidelines: Handle in well-ventilated spaces using explosion-proof equipment, avoid contact with eyes and skin, avoid breathing vapor, keep away from heat, spark sources and open flames, ground and bond containers during transfer
Storage Requirements: Store in tightly closed containers, in a cool, dry, well-ventilated place away from incompatible materials such as oxidizers and acids, attach proper hazard labels on containers, keep away from direct sunlight
Incompatible Materials: Oxidizing agents, acids, strong bases, halogens

Exposure Controls and Personal Protection

Occupational Exposure Limits: ACGIH TLV 0.5 ppm (skin), OSHA PEL none established, NIOSH REL none listed; maintain airborne concentrations below recommended limits
Engineering Controls: Use local exhaust ventilation, process enclosures, safety showers and eyewash stations should be accessible
Personal Protective Equipment: Chemical-resistant gloves (nitrile, neoprene), splash-proof goggles or face shield, flame-retardant lab coats, impervious footwear, suitable respiratory protection for vapor exposure (organic vapor cartridge respirators)
Hygiene Measures: Wash hands, arms, and face thoroughly after handling, launder contaminated clothing before reuse, do not eat, drink, or smoke in work area

Physical and Chemical Properties

Appearance: Clear to pale yellow liquid
Odor: Powerful, offensive, reminiscent of skunk or natural gas odorant
Odor Threshold: Detectable at less than 0.1 ppm
pH: Not applicable
Boiling Point: 96–98°C (204–208°F)
Melting Point: -145°C (-229°F)
Flash Point: 6°C (43°F) closed cup
Evaporation Rate: Rapid
Flammability: Flammable
Explosion Limits: Lower 1.7% vol, Upper 10.6% vol in air
Vapor Pressure: 48 mmHg at 20°C
Vapor Density: 2.9 (air = 1)
Relative Density: 0.83–0.87 g/cm³ at 20°C
Solubility: Slightly soluble in water, miscible with most organic solvents
Partition Coefficient (log Kow): 2.2
Auto-ignition Temperature: 350°C (662°F)
Decomposition Temperature: Not established
Viscosity: Low, similar to water

Stability and Reactivity

Chemical Stability: Stable under normal storage and handling conditions, decomposes with heat or light, generates toxic fumes on decomposition
Possibility of Hazardous Reactions: May react violently with oxidizing agents, reacts with acids liberating hydrogen sulfide gas, poses fire and explosion risk with air under certain conditions
Conditions to Avoid: Heat, open flames, sparks, sunlight, static discharge
Incompatible Materials: Strong oxidizers, acids, halogens, peroxides
Hazardous Decomposition Products: Sulfur oxides, hydrogen sulfide, carbon monoxide, carbon dioxide

Toxicological Information

Routes of Exposure: Inhalation, skin and eye contact, ingestion
Acutely Toxic Effects: Headache, nausea, vomiting, weakness, dizziness, chemical pneumonitis if vapor inhaled at high concentrations, skin and eye burns possible
Chronic Effects: Long-term exposure may cause dermatitis, respiratory irritation, may aggravate preexisting skin or lung conditions
LD50 (Oral, rat): Approximately 674 mg/kg
LD50 (Dermal, rabbit): Not available
LC50 (Inhalation, rat): Not available
Carcinogenicity: Not listed by IARC, NTP or OSHA
Mutagenicity/Reproductive Toxicity: Not enough data available
Additional Symptoms: Central nervous system depression, pulmonary edema in extreme cases

Ecological Information

Ecotoxicity to Aquatic Life: Extremely toxic to fish and aquatic invertebrates, possible bioaccumulation
Persistence and Degradability: Moderately persistent, undergoes slow biodegradation in soil and water, volatilizes from water surfaces
Mobility in Soil: Expected to have limited mobility, possible migration to groundwater in low-adsorption soils
Bioaccumulation Potential: Moderate based on log Kow
Environmental Precautions: Prevent product from entering water bodies, risk of long-term adverse consequences to aquatic systems

Disposal Considerations

Waste Treatment Methods: Incinerate in a chemical incinerator equipped with afterburner and scrubber, observe local, regional, national, and international regulations
Disposal of Containers: Rinse thoroughly and puncture before disposing as hazardous waste, avoid release to environment
Special Considerations: Label all waste, transportation and disposal must comply with environmental and safety regulations, spill cleanup material must also be treated as hazardous

Transport Information

UN Number: UN2347
Proper Shipping Name: Isobutyl Mercaptan
Transport Hazard Class: 3 (Flammable liquid), 6.1 (Toxic substance, if applicable)
Packing Group: II
Labels and Markings: Flammable Liquid, Toxic (if required), Marine Pollutant
Special Transport Precautions: Keep containers upright and tightly closed, secure during transport, avoid temperature extremes, segregate from food and incompatibles
Regulatory Transport Listings: Listed under IMDG, ICAO/IATA, and DOT guidelines

Regulatory Information

OSHA Status: Classified as a hazardous chemical according to OSHA Hazard Communication Standard
TSCA Listing: Listed in the Toxic Substances Control Act inventory
SARA Title III: Reportable under Section 302 and 311/312 (acute health hazard, fire hazard), Section 313 not listed
RCRA Status: Hazardous waste (D-code), subject to specific disposal requirements
State Regulations: May appear on Right-to-Know lists in selected states
International Restrictions: Subject to international regulations regarding flammable and environmentally hazardous substances
Labeling Requirements: GHS labeling for flammability and acute toxicity, complete hazard and precaution statements