Material Safety Data Sheet for Dimethyl Disulfide (DMDS)

Identification

Product Name: Dimethyl Disulfide
Synonyms: DMDS, Methyldisulfide
Chemical Formula: C2H6S2
CAS Number: 624-92-0
EC Number: 210-871-0
Recommended Use: Used as a chemical intermediate, agricultural fumigant, and solvent
Supplier Details: Manufacturers and distributors list addresses and emergency contact numbers on the container label

Hazard Identification

GHS Classification: Flammable liquid (Category 3), Acute toxicity (Category 4, Oral, Inhalation, Dermal), Skin irritation (Category 2), Eye irritation (Category 2A), Specific target organ toxicity-single exposure (Category 3, Narcotic effects), Hazardous to aquatic environment (Category 2)
Signal Word: Danger
Hazard Statements: Flammable liquid and vapor, harmful if swallowed/inhaled/in contact with skin, causes skin and eye irritation, may cause drowsiness or dizziness, toxic to aquatic life
Pictograms: Flame, Exclamation mark, Environment
Precautionary Statements: Keep away from heat, sparks, open flames; avoid breathing vapor; wear protective gloves, clothing, and eye protection; wash thoroughly after handling; avoid release to the environment

Composition / Information on Ingredients

Chemical Name: Dimethyl Disulfide
Concentration: >99%
Impurities: Trace levels of methyl mercaptan and other sulfur compounds
Hazardous Components: No additional hazardous components above threshold specified by regulatory standards

First Aid Measures

Inhalation: Move person to fresh air, keep at rest, seek medical attention for persistent symptoms
Skin Contact: Remove contaminated clothing, wash affected areas with soap and water, seek medical advice for irritation
Eye Contact: Rinse cautiously with water for at least 15 minutes, remove contact lenses if present and easy, consult medical attention
Ingestion: Rinse mouth, do not induce vomiting, immediately get medical assistance
Long-Term Effects: Sensitization and repeated exposure symptoms may include headaches, central nervous system depression, respiratory tract irritation

Fire-Fighting Measures

Suitable Extinguishing Media: Carbon dioxide, dry chemical powder, alcohol-resistant foam
Unsuitable Extinguishing Media: Direct water jet
Special Hazards: Emits toxic fumes of sulfur oxides and carbon oxides during combustion, vapors may form explosive mixtures with air
Protective Equipment for Firefighters: Self-contained breathing apparatus and full protective suit
Firefighting Procedures: Use water spray to cool containers, remove from fire area if safely possible, prevent water runoff from entering drains

Accidental Release Measures

Personal Precautions: Evacuate nonessential personnel, wear protective clothing, prevent inhalation and skin contact
Environmental Precautions: Prevent spill from entering drains, soil, waterways, alert authorities if large spill threatens to contaminate environment
Cleanup Methods: Absorb with inert material (sand, diatomaceous earth), collect in suitable, labeled containers for disposal, ventilate area, wash spill site after material pickup
Reference to Other Sections: Refer to exposure controls and personal protection guidelines for further details

Handling and Storage

Handling: Keep container tightly closed, use only in well-ventilated areas, avoid all sources of ignition, do not breathe vapor, avoid contact with skin and eyes, use spark-proof tools and explosion-proof equipment, ground container and receiving equipment
Storage: Store in cool, dry, well-ventilated, fireproof area, keep away from incompatible substances such as oxidizing agents and strong acids, label all storage areas, keep out of reach of children, do not store near food, feed, or drinking water
Special Precautions: Keep away from sunlight, segregate from oxidizers and halogens, keep storage temperature low to limit vapor generation, regularly inspect containers for leaks

Exposure Controls and Personal Protection

Exposure Limits: ACGIH TLV: 0.5 ppm (1.9 mg/m³) TWA; OSHA does not have a PEL specifically for DMDS
Engineering Controls: Local exhaust ventilation, process enclosure, explosion-proof ventilation systems
Personal Protective Equipment: Chemical-resistant gloves (nitrile, neoprene), flame-retardant clothing, safety goggles or face shield, approved respirator for short term or emergency exposure
Hygiene Measures: Wash hands before breaks and after handling, remove contaminated clothing and clean before reuse, avoid eating or drinking in work area

Physical and Chemical Properties

Appearance: Colorless to pale yellow liquid
Odor: Strong, unpleasant, rotten cabbage/sulfur odor
pH: Not applicable
Melting Point: -85 °C
Boiling Point: 109 °C
Flash Point: 21 °C (closed cup)
Auto-ignition Temperature: 270 °C
Explosive Limits: 1.1%–24% (v/v) in air
Vapor Pressure: 38 mm Hg at 25 °C
Vapor Density: 3.5 (air = 1)
Solubility: Slightly soluble in water, miscible with most organic solvents
Specific Gravity: 1.06 (water = 1)
Evaporation Rate: 1.3 (butyl acetate = 1)

Stability and Reactivity

Chemical Stability: Stable under recommended conditions, sensitive to elevated temperatures and open flames
Reactivity: Highly flammable, reacts with strong oxidizers, acids, halogens, may form explosive mixtures with air
Hazardous Decomposition Products: Produces sulfur oxides, carbon monoxide, carbon dioxide when burned
Polymerization: Does not undergo hazardous polymerization

Toxicological Information

Acute Toxicity: Oral LD50 (rat): 190 mg/kg; Inhalation LC50 (rat): 340 ppm (4 h); Dermal LD50 (rabbit): 5968 mg/kg
Chronic Effects: Repeated exposure may affect nervous system, kidneys, and liver; symptoms include dizziness, headache, nausea, fatigue, respiratory irritation, confusion in higher exposures
Skin and Eye Contact: Causes irritation, may result in redness, burning, temporary blindness for eye exposure
Sensitization: No known sensitization through skin contact, but caution necessary
Carcinogenicity: Not listed by IARC, NTP, or OSHA as a known carcinogen
Other Effects: Inhalation of high concentrations may cause central nervous system depression, narcosis, or respiratory distress

Ecological Information

Eco-toxicity: Toxic to aquatic life, EC50 (Daphnia magna, 48h): 2.9 mg/L
Persistence and Degradability: Moderately biodegradable, forms sulfates and other sulfur-containing oxidation products
Bioaccumulation: Potential for bioaccumulation in aquatic organisms
Mobility in Soil: Low adsorption potential, likely to leach into groundwater
Other Adverse Effects: Contributes to odor pollution, detectable by smell at extremely low concentrations, may contribute to formation of acid rain due to sulfur emissions

Disposal Considerations

Waste Disposal Methods: Incinerate in approved chemical waste facility, do not allow to enter sewers, waterways, or soil, observe all local, regional, and national regulations
Container Disposal: Empty containers retain product residue, follow state and local rules for hazardous waste treatment, puncture and triple rinse before disposal, avoid reuse for any other purposes
Special Precautions for Disposal: Work with certified hazardous waste contractor, document chain of custody, keep disposal records for regulatory compliance

Transport Information

UN Number: 2381
UN Proper Shipping Name: Dimethyl Disulfide
Transport Hazard Class: 3 (Flammable liquid)
Packing Group: II
Label Requirements: Flammable Liquid label, Environmental Hazard label (if transported in quantities above regulatory threshold)
Marine Pollutant: Yes
Special Transport Precautions: Segregate from oxidizers, acids, ensure containers secured and protected from damage, verify electrical equipment is explosion-proof in transport area

Regulatory Information

TSCA: Listed on US TSCA Inventory
SARA 313: Subject to reporting under SARA Title III, Section 313 (DMDS is a toxic chemical under US EPA regulations)
OSHA: Covered under Hazard Communication Standard, must display appropriate hazard warnings
EPA: Regulated under CERCLA for reportable quantities, regulated as a hazardous air and water pollutant
REACH: Registered under EC Regulation 1907/2006 (REACH) in Europe
Other Regulations: Local chemical control laws may require additional environmental releases reporting, ensure up-to-date compliance documentation, supply updated safety training for handlers and emergency responders