Methylene Chloride, Dichloro Methane, Methane Dichloride, Methylene Dichloride, 75-09-2

Methylene Chloride (Dichloromethane, CAS No: 75-09-2)

General Information

• Chemical Name: Dichloromethane (Methylene Chloride)

• Formula: CH₂Cl₂

• Molecular Weight: 84.93 g/mol

• Appearance: Colorless, volatile liquid

• Odor: Sweet, ether-like

• Density: 1.33 g/cm³

Physical & Chemical Properties

• Boiling Point: 39.6–40 °C

• Melting Point: -95 to -97 °C

• Water Solubility: 13–20 g/L (20–25 °C)

• Miscibility: Mixes with ethanol, ether, dimethylformamide

• Flammability: Non-flammable, but releases toxic chloride fumes at high temperatures

Production Methods

1. Methanol + HCl → Methyl Chloride (CH₃Cl)

2. Methyl Chloride + Cl₂ → Dichloromethane (CH₂Cl₂) + HCl

• Conducted in gas phase, photolytic or catalytic processes.

• By-products: Chloroform, Carbon Tetrachloride.

Applications

• Chemical Industry: Paints, varnishes, plastics, resins, adhesives.

• Rubber Industry: Solvent for natural and synthetic rubber.

• Metal Industry: Degreasing and surface cleaning.

• Pharmaceuticals: Solvent in drug production, recrystallization of antibiotics and vitamins.

• Food Industry: Extraction of caffeine, cocoa, hops (restricted use).

• Aerosols & Adhesives: Strong solvent, flame retardant, viscosity reducer.

• Paint Removers: Effective due to high solvency.

• Electronics: Printed circuit board manufacturing.

• Polymers & Plastics: Polyurethane foam cleaning, polycarbonate resin production, cellulose triacetate for film.

Health & Safety

• Exposure Routes: Inhalation, skin contact, ingestion.

• Risks:

  • Central nervous system effects (dizziness, numbness).

  • Respiratory distress, potentially fatal at high concentrations.

  • Possible carcinogenic effects with prolonged exposure.

• Precautions:

  • Avoid inhalation, ensure proper ventilation.

  • Use PPE (respirators, gloves, goggles).

  • Storage: 15–25 °C, sealed containers, away from heat and light.

Environmental Impact

• Classified as a VOC (Volatile Organic Compound), contributing to air pollution.

• Must not be released into sewage or surface waters.

• Fish toxicity: LC50 = 310 mg/L (96h).

Packaging & Transport

• Packaging: 270 kg drums, IBC, bulk.

• Transport Classification: ADR/RID Class 6.1 (toxic substance).