Material Safety Data Sheet (MSDS): Dimethyl Sulfone (MSM)

1. Identification

Product Name: Dimethyl Sulfone
Synonyms: Methylsulfonylmethane, MSM, DMSO2
Chemical Formula: C2H6O2S
CAS Number: 67-71-0
Recommended Use: Dietary supplement, sulfur source in animal feeds, research laboratory chemical
Manufacturer/Supplier: Details vary per supply source; typical industrial manufacturers are listed in safety databases
Emergency Phone: Check national poison control center and local emergency contacts
Address: Supplier’s full address and contact details as indicated on shipment documentation

2. Hazard Identification

GHS Classification: Not classified as hazardous by GHS criteria
Physical Hazards: Substance is stable under normal conditions; forms crystals or powder
Health Hazards: May cause mild respiratory irritation, slight skin or eye irritation in sensitive individuals
Environmental Hazards: Not considered a significant environmental risk in small quantities, but keep spills out of water supplies
Signal Word: None required by most regulatory agencies
Hazard Statements: Avoid excessive inhalation of dust and direct eye contact
Precautionary Statements: Use with adequate ventilation, avoid dust buildup, practice good hygiene

3. Composition / Information on Ingredients

Chemical Identity: Dimethyl Sulfone
Concentration: >99% pure
Impurities: Negligible at pharmaceutical or food-grade; trace solvents or related organosulfur byproducts possible
Additives: None expected in standard supply

4. First Aid Measures

Inhalation: Move to fresh air, breathe slowly, seek medical care if symptoms like coughing or throat irritation persist
Skin Contact: Wash thoroughly with plenty of water and mild soap, remove contaminated clothing
Eye Contact: Rinse eyes with running water for at least 15 minutes; medical attention if irritation stays
Ingestion: Rinse mouth, drink water to dilute; medical help if feeling unwell or large amounts swallowed
General Advice: Show physician the MSDS, keep packaging for reference

5. Fire-Fighting Measures

Suitable Extinguishing Media: Use dry chemical, CO2, water spray, or foam to put out flames
Fire/Explosion Risks: Not flammable under normal use, but dust dispersion in air could form explosive mixtures
Hazardous Combustion Products: Oxides of sulfur, carbon monoxide, carbon dioxide
Fire Fighter Precautions: Wear self-contained breathing apparatus and protective clothing, evacuation of downwind area suggested in fire involving large quantities

6. Accidental Release Measures

Personal Precautions: Use dust mask, gloves, safety goggles; keep unnecessary people away
Environmental Precautions: Prevent spillage from reaching drains or waterways, pick up granules quickly
Spill Cleanup: Collect solid spill using a vacuum or broom and shovel, place in suitable closed containers, minimize dust
Disposal: Use municipal or approved chemical waste site, follow local regulations
Decontamination: Wash spill area with water after removal of bulk material

7. Handling and Storage

Precautions for Safe Handling: Avoid dust formation, use goggles and gloves, provide good ventilation
Storage Conditions: Store in sealed containers in a cool, dry, well-ventilated space, away from direct sunlight and strong acids or oxidizers
Process Controls: Keep packages tightly closed, ground all equipment
Incompatibilities: Strong oxidizers, strong acids, bases; prevent contamination

8. Exposure Controls and Personal Protection

Occupational Exposure Limit: No ACGIH or OSHA limit for MSM; use general nuisance dust limits (10 mg/m³ total dust, 3 mg/m³ respirable dust)
Engineering Controls: Use local exhaust or general room ventilation, dust extraction equipment
Personal Protective Equipment: Safety glasses/goggles, lightweight chemical-resistant gloves, dust mask or N95 respirator for airborne powder
Hygiene Measures: Wash hands after handling, avoid eating, drinking, or smoking in work area
Protective Clothing: Lab coat, long-sleeved shirt recommended for bulk handling

9. Physical and Chemical Properties

Appearance: White, odorless, crystalline powder or granules
Molecular Weight: 94.13 g/mol
Melting Point: 109–110°C
Boiling Point: Decomposes above 238°C
Solubility: Highly soluble in water; soluble in ethanol
Vapor Pressure: Negligible
Density: 1.31 g/cm³
pH (1% solution): 6.5–7.5
Flash Point: Not flammable by conventional ignition
Odor Threshold: Odorless
Octanol/Water Partition Coefficient: Log Pow ≈ -2

10. Stability and Reactivity

Chemical Stability: Stable under normal handling and storage conditions
Hazardous Reactions: No dangerous polymerization under recommended use
Conditions to Avoid: Excess heat, moisture, open flames, sources of ignition
Incompatible Materials: Powerful oxidizing agents, strong acids, strong bases
Decomposition Products: Oxides of sulfur, carbon oxides; possible release of small amounts of methylsulfonic acid during combustion

11. Toxicological Information

Routes of Exposure: Inhalation, eye and skin contact, ingestion
Acute Toxicity: Oral LD50 (rat): >17,900 mg/kg; low acute toxicity for humans
Chronic Toxicity: Long-term use in supplement doses shows low risk; clinical studies point to rare mild GI discomfort
Skin/Eye Effects: Mild irritation in sensitive persons; not known to cause allergic reactions
Carcinogenicity: Not listed as carcinogenic by IARC, NTP, or OSHA
Mutagenicity: Negative in standard tests
Reproductive Toxicity: Animal studies show no significant effects; human reproductive safety not comprehensively studied
Sensitization: No expected skin or respiratory sensitization based on current data

12. Ecological Information

Ecotoxicity: No significant hazard recognized for aquatic life at normal environmental concentrations
Persistence and Degradability: Biodegradable in soil and water over weeks
Bioaccumulation Potential: Low, due to high water solubility and low log Pow
Mobility in Soil: Likely to leach; disperses easily in aqueous phase
Other Adverse Effects: Avoid direct release to waterways and soil in bulk

13. Disposal Considerations

Waste Methods: Dispose as ordinary chemical waste in accordance with local, regional, national, or international regulations
Disposal Containers: Use sealed, labeled drums or bins for solid form
Municipal or Industrial Waste Handling: Most facilities accept; confirm with site manager
Incineration/Destruction: Not required unless contaminated by hazardous materials
Avoid: Flushing large amounts to drains or environment; prevent dust emission during waste handling

14. Transport Information

UN Number: Not regulated as a dangerous good
Proper Shipping Name: Dimethyl Sulfone
Transport Hazard Class: Not classified
Packing Group: Not assigned
Environmental Hazards: No significant risk; not a marine pollutant
Special Precautions: Protect packaging from tears, leaks, or dust emission
Labels: No hazard label required by IATA, IMDG, or DOT regulations

15. Regulatory Information

Inventory Status: Listed or compliant under US TSCA, EU REACH, Canada DSL, Australia AICS
Workplace Safety: Covered under OSHA General Industry Standard; not subject to specific safety requirements
Labeling Requirements: Complies with standard chemical labeling for non-hazardous materials
SARA Title III Sec 302 / 304 / 313: Not listed as a hazardous chemical
California Prop 65: Not listed
EU Regulations: Not classified under CLP; no restriction under biocidal or pharma frameworks
WHMIS Classification (Canada): Non-controlled
Other Regulations: Product use governed by local workplace, environment, and transportation safety codes