CH2Cl2

CH2Cl2, also known as dichloromethane or methylene chloride, is a chlorinated hydrocarbon solvent with the formula CH2Cl2. It is a colorless, highly volatile liquid used widely in industry as a solvent for coatings, degreasing metals, and in the production of pharmaceuticals and polymers, as well as an extraction and chromatography solvent.

Physically, dichloromethane boils at about 39.6°C and has a density of roughly 1.32 g/cm3 at 20°C, making it denser than water. It is immiscible with water or only sparingly soluble, while freely dissolving many organic compounds. Its vapors are dense and can accumulate in low-lying areas, and it has a characteristic, mildly sweet odor. It is primarily produced by the chlorination of methane or methanol, followed by purification.

Health and safety considerations are central to handling CH2Cl2. It is toxic if inhaled or absorbed through the skin and can cause dizziness, headaches, and central nervous system depression; high exposures can be life-threatening. Chronic exposure has raised cancer risk concerns, and the substance is classified by IARC as probably carcinogenic to humans (Group 2A). In the body, methylene chloride can be metabolized to carbon monoxide, contributing to hypoxia. It is also flammable and may release phosgene under certain oxidizing conditions, underscoring the need for ventilation, proper PPE, and strict handling and storage in accordance with occupational safety guidelines.

Environmental and regulatory aspects: as a volatile organic compound, CH2Cl2 volatilizes readily and degrades in the atmosphere; it is managed as hazardous waste when discarded. Waste disposal follows local regulations for hazardous chemical waste.