Dimethyl Sulfide (DMS) Material Safety Data Sheet (MSDS)

Identification

Chemical Name: Dimethyl Sulfide
Synonyms: DMS, Methylthio-methane, Thioether
CAS Number: 75-18-3
Molecular Formula: C2H6S
Molecular Weight: 62.13 g/mol
Recommended Use: Industrial chemical, chemical intermediate, used in petrochemical manufacturing, and sometimes in laboratories for synthesis or research testing processes.
Manufacturer/Supplier: Details listed on commercial batch paperwork; usually specialty chemical providers and bulk chemical suppliers distribute it.
Emergency Contact: CHEMTREC or regional hazardous chemical incident number specific to your location.

Hazard Identification

GHS Classification: Flammable liquid (Category 2), Acute toxicity inhalation (Category 4), Skin irritation (Category 2), Eye irritation (Category 2A), Specific target organ toxicity single exposure (Category 3)
Signal Word: Danger
Hazard Statements: Highly flammable liquid and vapor; harmful if inhaled or swallowed; causes skin and eye irritation; may cause respiratory irritation.
Pictograms: Flame, Exclamation Mark
Precautionary Statements: Keep away from heat, sparks, flames, and hot surfaces; avoid breathing fumes or vapors; use only outdoors or in well-ventilated area; wear protective gloves, eye protection, and face protection; in case of fire, use foam or dry chemical for extinction; wash hands thoroughly after handling.

Composition / Information on Ingredients

Chemical Name: Dimethyl Sulfide
Content: 99% or higher by weight
Impurities: Trace amounts of water, methyl mercaptan, or other organic sulfides can be present depending on source.
CAS Number: 75-18-3
EC Number: 200-846-2
Molecular Structure: (CH3)2S

First Aid Measures

Inhalation: Move affected person outdoors or to fresh air immediately. Contact medical help if breathing problems start or persist. Loosen tight clothing and keep airways clear. Oxygen or artificial respiration if interrupted breathing is noticed.
Skin Contact: Take off any contaminated clothing and rinse skin quickly with lots of water. Seek medical attention if irritation or redness remains.
Eye Contact: Rinse with water for several minutes while holding eyelids apart. Contact doctor if discomfort or eye damage appears.
Ingestion: Do not force vomiting. Rinse mouth gently and offer water only if person is fully awake and alert. Seek urgent medical attention as ingestion brings serious toxicity risks.
General Symptoms: Dizziness, headache, nausea, sore throat, and breathing irritation.

Fire-Fighting Measures

Suitable Extinguishing Media: Alcohol-resistant foam, carbon dioxide, dry chemical, water spray. Avoid aiming large streams of water as that can spread burning liquid.
Special Hazard: DMS forms mixtures with air which can explode if ignited. Vapors move easily and may travel to sources of ignition by distant routes.
Hazardous Combustion Products: Carbon monoxide, sulfur oxides, soot, irritating fumes.
Firefighting Instructions: Evacuate area; use suitable fire-resistant protective gear and breathing equipment. Approach from upwind and cool nearby tanks with water spray.
Special Notes: Prevent fire water runoff from entering drains or open waterways as chemical runoff causes harm to aquatic systems.

Accidental Release Measures

Personal Precautions: Avoid all contact with spilled material; wear appropriate respiratory, skin, and eye protection. Remove all sources of ignition right away.
Environmental Precautions: Stop leaks if safe; prevent entry of DMS into drains, sewers, surface water, or soil.
Containment: Use non-sparking tools and absorb spill using inert absorbent (e.g., sand, vermiculite). Scoop into chemical waste container and seal thoroughly.
Cleanup: Ventilate area and wash spill site after material is picked up. Dispose using safe, approved chemical waste protocols.

Handling and Storage

Handling: Avoid inhaling vapors, skin or eye contact. Handle only in areas with fresh air movement or exhaust ventilation. Keep away from strong oxidizers, acids, and alkalis. Use spark-proof tools and equipment to lower fire hazards.
Storage: Store DMS in tightly closed steel or glass containers in cool, dry areas. Keep away from heat, sunlight, open flames, or sources of static electricity. No smoking nearby. Install proper ventilation and spill containment systems.
Special Precautions: Label containers clearly. Regularly inspect for leaks or corrosion.

Exposure Controls and Personal Protection

Control Parameters: Occupational Exposure Limit (OEL), ACGIH TLV: 10 ppm; OSHA PEL not formally set but follows similar standards for flammable organosulfides.
Engineering Controls: Use fume hoods, explosion-proof ventilation, and continuous air monitoring. Install local exhaust at places where DMS is used or transferred.
Personal Protective Equipment (PPE): Chemical-resistant gloves (nitrile, neoprene), splash goggles or full face shield, long-sleeve chemical-resistant clothing. Use approved half-mask or full-face respirators if vapor levels rise.
Hygiene Measures: Wash hands and face after chemical contact. Keep food, drinks, and tobacco out of work zone.

Physical and Chemical Properties

Appearance: Colorless, clear liquid
Odor: Strong, unpleasant odor, cabbage-like or similar to rotten vegetables
Odor Threshold: Very low (less than 1 ppm, detectable by smell quickly)
pH: Not applicable
Melting Point: -98°C
Boiling Point: 37°C
Flash Point: -35°C (closed cup)
Evaporation Rate: High (above similar low molecular organics)
Flammability: Highly flammable liquid and vapor
Vapor Pressure: 533 mmHg at 25°C
Vapor Density: 2.1 (air = 1)
Solubility: Slightly soluble in water; miscible with most organic solvents
Partition Coefficient: Log Pow 0.81
Auto-ignition Temperature: 205°C
Decomposition Temperature: Not well defined; decomposes with flames or strong oxidizing agents
Viscosity: Very low, typical of small organic liquids.

Stability and Reactivity

Stability: Stable at normal temperature and pressure with adequate ventilation and no ignition source nearby.
Hazardous Reactions: Rapidly reacts with strong oxidizers, halogens, acids.
Conditions to Avoid: Heat, sparks, open flame, static discharge.
Incompatible Materials: Strong acids, oxidizing agents, alkali metals.
Hazardous Decomposition Products: Sulfur oxides, toxic fumes, methane, carbon monoxide.
Polymerization: Does not polymerize.

Toxicological Information

Routes of Exposure: Inhalation, ingestion, eyes, skin.
Acute Toxicity: LC50 (rat, inhalation, 4 h): about 40,250 mg/m3; oral LD50 (rat): about 820 mg/kg.
Skin Corrosion/Irritation: Causes moderate to severe irritation, redness, dryness with prolonged or repeated contact.
Eye Damage/Irritation: Severe irritation possible; tears, conjunctivitis, pain.
Respiratory Effects: Coughing, headache, dizziness, nausea, breathing trouble and possible chemical pneumonitis at high exposure.
Ingestion Effects: Serious toxicity, stomach pain, vomiting, dizziness, systemic organ effects at moderate to high doses.
Delayed or Chronic Toxicity: Repeated exposure may cause lasting nerve and liver damage.
Additional Information: No known cancer or reproductive risks in animal or human data for DMS.

Ecological Information

Ecotoxicity: Acute aquatic toxicity to fish and invertebrates significant; LC50 (fish, 96 h): approximately 17 mg/L.
Persistence and Degradability: Moderately biodegradable in soil and water, but can contribute to odor issues in water and municipal water supplies.
Bioaccumulation Potential: Unlikely to accumulate; log Pow indicates low bioconcentration.
Mobility in Soil: High mobility in soil; volatilizes and percolates through soil easily due to vapor pressure.
Other Hazards: Strong odors create nuisance problems and overwhelm local flora and fauna near industrial sites.

Disposal Considerations

Waste Treatment Methods: Collect all liquid and solid DMS waste in labeled, sealable chemical containers.
Disposal Methods: Dispose as hazardous waste in line with local and federal regulations. Never release into surface water, sewers, or unregulated landfills.
Incineration: Approved chemical waste incineration with afterburner and flue gas scrubber recommended.
Contaminated Packaging: Rinse triple, puncture, then dispose as hazardous waste.
Consultation: Local waste management authority and environmental safety office provide site-specific regulations.

Transport Information

UN Number: 2381
UN Proper Shipping Name: Dimethyl sulfide
Transport Hazard Class: 3 (Flammable liquid)
Packing Group: II
Label: Flammable liquid
Marine Pollutant: Not listed as marine pollutant, though spills should be contained
Special Transport Precautions: Ship in metal drums or tanks; keep upright; away from sources of heat and ignition; emergency response documentation carried at all times.

Regulatory Information

Workplace Safety: Included in OSHA’s Hazard Communication Standard, must be handled with full safety labeling at all sites.
Environmental Regulations: Listed with EPA under the Clean Air Act and relevant state hazardous material lists; some regions limit air emissions and discharges.
GHS Label Elements: Matches requirements under GHS revision and US, EU, and Asia-Pacific regional adaptations.
Reporting Thresholds: SARA Title III section 313, subject to reporting at threshold amounts; in the EU carries REACH pre-registration and restriction monitoring.
Other Local Requirements: May be subject to special environmental air quality permits in metro or industrial areas, especially near residential neighborhoods.