Dichloromethane (DCM, Methylene Chloride) is a colorless, volatile organic solvent widely used in industrial and pharmaceutical applications. It belongs to the chlorinated methane family and is known for its strong dissolving power and low boiling point.

Basic Information

Chemical Name: Dichloromethane (Methylene Chloride) CAS No.: 75-09-2 EINECS No.: 200-838-9 Molecular Formula: CH₂Cl₂ Molecular Weight: 84.93 UN No.: 1593 Hazard Class: 6.1 (Toxic) / 3 Packing Group: III HS Code: 29031200 Appearance: Clear, colorless liquid Boiling Point: 39.6 °C Melting Point: -96.7 °C Density (20 °C): 1.325 g/cm³ Flash Point: Non-flammable under normal conditions Vapor Pressure (20 °C): 47.4 kPa Solubility: Slightly soluble in water; miscible with ethanol, ether, ketones and most organic solvents

Key Properties

Dichloromethane exhibits strong solvency for oils, resins, waxes and rubber, making it one of the most commonly used chlorinated solvents. Its low boiling point of 39.6 °C allows for easy evaporation and recovery, which is highly advantageous in extraction and cleaning processes. Although the liquid is non-flammable under normal conditions, exposure to high temperatures or open flames may decompose it into toxic gases such as phosgene and hydrogen chloride. Being denser than water (1.325 g/cm³) and immiscible with it, DCM sinks below the aqueous layer during liquid-liquid extraction.

Main Applications

Dichloromethane can act as a cleaning agent for degreasing electronic components and precision instruments. It serves as solvent and extractant for pharmaceutical extraction, adhesive production and paint stripping. Historically, it was applied as refrigerant and aerosol propellant. It also works as a chemical intermediate to manufacture other chloromethanes.

Storage & Transport

Dichloromethane should be stored in a cool, dry and well-ventilated area at temperatures not exceeding 30 °C, kept away from heat sources, open flames and direct sunlight, and protected from moisture. Containers must be kept tightly sealed and stored separately from oxidizers and strong alkalis. During transport, it is classified under UN1593 (Class 6.1) and must be shipped in corrosion-resistant, sealed drums such as iron or galvanized steel drums. It must never be transported together with foodstuffs. Operators should wear protective masks, chemical-resistant gloves and ensure adequate ventilation in the workplace.

Notes

Dichloromethane is a toxic and environmentally hazardous substance, particularly harmful to aquatic life. For export, a complete SDS/MSDS, UN hazard labeling and dangerous goods packaging certificate are required. Whether it qualifies as non-hazardous cargo depends on the specific content specification and the destination country's customs requirements; always verify with the relevant authorities in advance.