Methylene Chloride (Dichloromethane, DCM)

CAS No.: 75-09-2
Synonyms / IUPAC Name: Methylene Chloride, Dichloromethane (DCM)
Molecular Formula: CH₂Cl₂
Molecular Weight: 84.93 g/mol

Physicochemical Properties (Typical)

• Appearance: Colorless, clear liquid
• Melting/Freezing Point: Approximately –95 °C
• Boiling Point: Approximately 39.6–40 °C (at 1 atm)
• Density (20 °C): Approximately 1.32–1.33 g/cm³
• Vapor Pressure (20 °C): High (~350 mmHg) or ~453 hPa
• Solubility: Slightly soluble in water (approx. 13–20 g/L at 20–25 °C); miscible with organic solvents
• Flash Point: Not flammable under normal conditions; vapors can ignite under strong heating
• Explosive/Flammable Limits: Lower ~13% v/v; Upper ~23% v/v

Purity & Quality Standards

• Purity: Often ≥ 99.5% (GC) for high grade
• Non-volatile Residues: Minimal (e.g., ≤ 0.001% for HPLC grade)
• Documentation: Certificate of Analysis (COA) and Safety Data Sheet (SDS) provided

Applications / Uses

• Solvent in coatings, adhesives, inks, and cleaning systems
• Extraction solvent in pharmaceutical and chemical manufacturing
• Refrigerant, blowing agent, component in aerosol applications and food decaffeination processes

Safety & Handling

• Health Hazards: Vapours may cause dizziness, headache, CNS effects; possible carcinogen (IARC Group 2A)
• Routes of Exposure: Inhalation, skin contact, eye contact
• Precautions:
  • Use in well-ventilated areas
  • Wear suitable gloves and eye protection
  • Avoid breathing vapour and prevent skin/eye contact
• Reactivity: Incompatible with strong oxidizers, alkali metals, powdered metals, amines, bases
• First Aid Measures:
  • Inhalation: Move to fresh air, keep comfortable for breathing
  • Skin: Wash with soap and water
  • Eyes: Rinse cautiously with water for several minutes
  • Ingestion: Seek medical attention
• Carcinogenicity Note: Suspected of causing cancer in humans (animal evidence sufficient)

Packaging & Storage

• Packaging: Seal in solvent-compatible containers designed for halogenated liquids
• Storage Conditions: Cool (<30 °C), dry, well-ventilated area away from ignition sources and incompatible materials
• Container Closure: Keep tightly closed to prevent vapour release
• Shelf Life: Typically 12–24 months under recommended storage conditions