2-Butanone (Methyl Ethyl Ketone, MEK)

   CAS No.: 78-93-3
   Synonyms / IUPAC Name: 2-Butanone; Methyl Ethyl Ketone (MEK)
   Molecular Formula: C₄H₈O
   Molecular Weight: ~72.11 g/mol

Physicochemical Properties (Typical)

• Appearance: Clear, colourless liquid with a sharp, mint- or acetone-like odor
• Melting / Freezing Point: Approx. –86 °C
• Boiling Point: Approx. 79–80 °C (at 1 atm)
• Density (20–25 °C): ~0.805 g/cm³
• Refractive Index (n²⁰ᴰ): ~1.379
• Vapour Pressure (20 °C): ~71 mmHg (≈9.5 kPa)
• Solubility: Partially miscible with water (≈25% by weight at 20 °C)
• Flash Point (Closed Cup): ~-6 °C to ~16 °C
• Explosive Limits in Air: Lower ~1.8% vol; Upper ~11.5% vol

Purity & Quality Standards

• Typical Purity: ≥ 99% (GC) for high-grade solvent applications
• Appearance: Clear, colourless, free from visible particulates or haze
• Analytical Methods: Gas chromatography for assay; moisture and non-volatile residues controlled
• Stability: Stable under normal storage when protected from ignition sources and strong oxidisers

Applications / Uses

• Widely used as an industrial solvent in coatings, adhesives, inks, resin systems, and cleaning/degreasing operations
• Intermediate in manufacturing of plastics, fibres, and other organic compounds
• Useful where a medium‐boiling ketone solvent with good evaporation profile is required

Safety & Handling

• Hazard Classification: Highly flammable liquid and vapour
• Health Hazards:
• Inhalation: May irritate respiratory system; may cause dizziness or drowsiness
• Skin Contact: Prolonged exposure may cause dryness or cracking
• Eye Contact: Causes serious eye irritation
• Precautions:
• Use in well-ventilated area; avoid vapour accumulation
• Keep away from heat, sparks, open flames and hot surfaces; ground and bond containers when transferring
• Wear protective gloves, eye/face protection and appropriate protective clothing
• Reactivity / Incompatibilities: Avoid contact with strong oxidisers, acids, and reactive metals; vapour may form explosive mixtures with air
• First Aid Measures:
• Inhalation: Move to fresh air; keep at rest; seek medical attention if symptoms persist
• Skin Contact: Remove contaminated clothing; wash thoroughly with soap and water
• Eye Contact: Rinse cautiously with water for several minutes; seek medical attention if irritation persists
• Ingestion: Do not induce vomiting; seek medical attention immediately

Packaging & Storage

• Packaging: Supplied in sealed solvent-compatible containers suited for flammable liquids (e.g., steel drums or lined containers)
• Storage Conditions: Store in a cool (<30 °C), dry, well-ventilated area away from ignition sources, direct sunlight, and incompatible materials
• Container Closure: Keep containers tightly closed when not in use to prevent vapour release and contamination
• Shelf Life: When stored properly, material remains stable for 12–24 months; inspect for colour change or contamination before use