Material Safety Data Sheet (MSDS): Dibutyl Disulfide

Identification

Product Name: Dibutyl Disulfide
Synonyms: DBDS, n-Butyl disulfide, Dibutyl disulphide
Chemical Formula: C8H18S2
CAS Number: 629-45-8
Recommended Use: Used as a solvent, lubricant additive, and chemical intermediate
Manufacturer Contact: See product label for supplier information and reach out to local representative for emergency numbers
Emergency Contacts: Local poison control center, fire department, or environmental authorities as appropriate

Hazard Identification

GHS Classification: Flammable liquid (Category 3), Acute Toxicity Oral (Category 4), Skin Irritation (Category 2), Eye Irritation (Category 2A), Specific Target Organ Toxicity - Single Exposure (Category 3, narcotic effects)
Signal Word: Warning
Hazard Statements: Flammable liquid and vapor. Harmful if swallowed. Causes skin irritation. Causes serious eye irritation. May cause drowsiness or dizziness.
Pictograms: Flame, Exclamation mark
Precautionary Statements: Keep away from heat/sparks/open flames/hot surfaces. Ground/bond container and receiving equipment. Use explosion-proof electrical equipment. Do not breathe vapor or mist. Wash skin thoroughly after handling. Wear protective gloves/eye protection.

Composition / Information on Ingredients

Chemical Name: Dibutyl Disulfide
Concentration: 98%–100% (by weight, varies by industrial source and purity)
Impurities: Trace levels of n-butyl mercaptan, other sulfur organics
Molecular Weight: 178.36 g/mol
EC Number: 211-096-0
Relevant Impurities: Major risk contributed by main ingredient.

First Aid Measures

Inhalation: Move to fresh air. If breathing becomes labored or symptoms develop, seek medical attention without delay. Use artificial respiration if breathing stops.
Skin Contact: Remove any contaminated clothing. Wash area thoroughly with soap and water. Seek medical advice if skin irritation persists.
Eye Contact: Flush immediately with plenty of water for at least 15 minutes, keeping eyelids open. Remove contact lenses if applicable and continue rinsing. Medical examination needed if irritation doesn't ease.
Ingestion: Do not induce vomiting. Rinse mouth with water. Give small sips of water if person is conscious. Immediate medical help should be sought.
Most Important Symptoms: Skin redness, itching, drowsiness, nausea, headache, and respiratory distress.
Notes for Physician: Treat symptomatically. Maintain airway and monitor for respiratory depression.

Fire-Fighting Measures

Suitable Extinguishing Media: Use alcohol-resistant foam, carbon dioxide, dry chemical, or water spray. Avoid direct water stream; may cause fire to spread.
Unsuitable Extinguishing Media: Do not use solid streams of water as splattering and spread of flames can result.
Fire Hazards: Vapors heavier than air; may travel considerable distance to source of ignition and flash back. Combustion generates sulfur oxides, carbon oxides, and other toxic vapors.
Protective Equipment: Firefighters require full protective gear and self-contained breathing apparatus. Approach windward to avoid toxic vapors.
Specific Methods: Contain fire water run-off. Cool containers with water spray to prevent possible explosions due to pressure build-up. Evacuate area and fight fire from a safe distance.

Accidental Release Measures

Personal Precautions: Evacuate unnecessary personnel. Don appropriate personal protective equipment including gloves, chemical splash goggles, and respirators when exposure to vapors is possible.
Environmental Precautions: Contain spill to prevent entry into soil, sewers, surface or groundwater. Report significant releases to local environmental authorities.
Methods for Cleaning Up: Cover with dry inert absorbent (sand, earth, or vermiculite), then sweep up and transfer to labeled containers for disposal. Use non-sparking tools; ventilate area. Wash spill area with water and detergent.
Disposal: See Disposal Considerations below for guidelines.

Handling and Storage

Handling: Use only in well-ventilated areas. Avoid breathing vapors or contact with skin and eyes. Wear suitable loose-fitting clothing to limit skin exposure. Transfer liquid with explosion-proof equipment. No smoking, eating, or drinking around area.
Storage: Keep container tightly closed, in a cool, dry, well-ventilated place away from sources of ignition, acids, and oxidizers. Store in original or compatible containers, clearly labeled. Prevent container damage and check regularly for leaks.
Incompatibility: Strong oxidizers, acids, sources of ignition; avoid contact with plastics or rubber which may degrade.
Special Considerations: Ground and bond containers during transfer to minimize risk of static discharge.

Exposure Controls and Personal Protection

Exposure Limits: No specific OSHA or ACGIH exposure limits for dibutyl disulfide; use general workplace standards for chemicals with similar properties.
Engineering Controls: Use mechanical exhaust or local ventilation. Ensure eyewash stations and safety showers are near.
Personal Protective Equipment: Safety goggles or face shield, chemically resistant gloves (nitrile or neoprene), antistatic protective clothing, and suitable respiratory protection (organic vapor cartridge respirator) if airborne concentrations are high.
Hygiene Practices: Wash hands and exposed areas after work. Remove sorely contaminated clothing immediately. Launder before reuse.
Environmental Controls: Prevent vapor or mist release into the air.

Physical and Chemical Properties

Appearance: Clear to pale yellow liquid
Odor: Pungent, unpleasant sulfurous odor
Odor Threshold: Low; offensive at small concentrations
pH (at 20°C): Not applicable (non-aqueous)
Melting Point/Freezing Point: −85°C
Boiling Point: 224°C
Flash Point: 96°C (closed cup)
Evaporation Rate: Slower than butyl acetate
Flammability: Flammable liquid
Explosive Limits: Lower 0.7% / Upper 6.6% (v/v in air)
Vapor Pressure: 0.3 mmHg (20°C)
Vapor Density: 6.2 (air = 1)
Relative Density: 0.98 g/cm³ (20°C)
Solubility: Insoluble in water; miscible with most organic solvents
Partition Coefficient (log Kow): 3.85
Auto-Ignition Temperature: 245°C
Decomposition Temperature: Not precisely established
Viscosity: Low to moderate (varies with temperature)

Stability and Reactivity

Chemical Stability: Stable under recommended storage conditions. Decomposes under strong heating, producing toxic gases.
Reactivity: Reacts with strong oxidizing agents, acids, and bases to yield sulfur oxides or flammable gases.
Possibility of Hazardous Reactions: May form flammable or toxic vapors upon contact with incompatible substances or in case of fire.
Conditions to Avoid: Heat, sparks, open flames, static discharges, and exposure to moisture.
Hazardous Decomposition Products: Carbon monoxide, carbon dioxide, sulfur oxides, and butyl mercaptan.

Toxicological Information

Routes of Exposure: Inhalation, skin absorption, ingestion, eye contact
Acute Toxicity: Oral (rat) LD50: ~500 mg/kg; Skin (rabbit) LD50: Data not well established
Inhalation: Causes respiratory tract irritation, headache, dizziness, drowsiness, and at high levels, narcosis.
Skin Contact: Irritation, possible redness, and discomfort; prolonged exposure can increase severity.
Eye Contact: Redness, tearing, pain, and blurred vision
Ingestion: Nausea, vomiting, gastrointestinal pain; serious poisoning if large quantities swallowed.
Chronic Effects: No reliable data on long-term effects, but repeated exposure may increase risks of dermatitis or central nervous system effects.
Carcinogenicity: Not classified as carcinogenic by IARC, NTP, or OSHA.
Other Health Effects: No current evidence for mutagenicity or reproductive toxicity for this material.

Ecological Information

Aquatic Toxicity: Harmful to aquatic organisms. May cause long-term adverse effects in aquatic environment. LC50 (Fish, 96 h): Data limited; expected to be in the range of tens of mg/L
Persistence and Degradability: Not readily biodegradable; expected to persist in soil and aquatic systems.
Bioaccumulative Potential: High; log Kow above 3 indicates potential for accumulation in aquatic species.
Mobility in Soil: Low water solubility limits movement through soil.
Other Adverse Effects: Breakdown products may have toxic effects on flora and fauna.
Special Precautions: Avoid release to natural waters and soil; containment and treatment considered good practice.

Disposal Considerations

Waste Treatment Methods: Incinerate in licensed chemical incinerator with afterburner and scrubber. Chemical should not enter drains, watercourses, or be disposed of with regular waste.
Contaminated Packaging: Empty containers should be decontaminated or disposed of under conditions applying to the product itself. Do not reuse packaging for other purposes.
Special Handling Notes: Keep all wastes labeled and segregated by hazard class. Work with local, state, or federal regulations and approved hazardous waste contractors.
Disposal Code: Follow hazardous organic waste category as set by local authorities.

Transport Information

UN Number: UN 2810
UN Proper Shipping Name: Toxic liquid, organic, n.o.s. (contains dibutyl disulfide)
Transport Hazard Class: 6.1 (Toxic substances)
Packing Group: III (moderate hazard)
Environmental Hazards: Marine pollutant
Transport Labels: Toxic, Marine Pollutant, Flammable liquid
Special Transport Precautions: Keep away from food and animal feeds. Transport only in approved containers and ensure vehicle is ventilated. Document and mark packages according to DOT, ADR, IMDG or IATA rules.
Emergency Procedures: Drivers and handlers must know the hazards and emergency response measures.

Regulatory Information

TSCA Status: Listed on U.S. TSCA Inventory
OSHA: Regulated as hazardous according to OSHA Hazard Communication Standard
EPA SARA Title III: Not specifically listed, but subject to reporting under general hazardous substance guidelines
RCRA: Not listed with specific waste code but may require hazardous waste handling
Canadian DSL/NDSL: Listed
REACH Registration: Registered as a phase-in substance in the EU
Other National Lists: Ensure compliance with local, state, and federal chemical safety protocols and labeling rules
Labeling Requirements: Containers must carry batch details, hazard pictograms, supplier information, and relevant warnings. Training and documentation form part of regulatory compliance for all handlers.