Dichloromethane

Dichloromethane, also known as methylene chloride, is a volatile, colorless liquid with the chemical formula CH2Cl2. It is widely used as an organic solvent and is valued for its ability to dissolve a broad range of compounds and for rapid evaporation. It is denser than water and has a relatively low boiling point, around 39.6°C, so it readily forms vapors at room temperature. Its solubility in water is limited (about 1.3 g/L at 20°C), while it dissolves many organic solvents.

Commercially, dichloromethane is produced by chlorinating methane under controlled conditions, often as part of larger chlorinated hydrocarbon processes. It occurs only in trace amounts in the environment and is released primarily through industrial uses and emissions. In air, it participates in photochemical reactions and is classified as a volatile organic compound with potential environmental and health effects.

Common uses of dichloromethane include paint stripping and surface cleaning, degreasing of metal parts, and as an intermediate in the manufacture of polymers, pharmaceuticals, and electronic components. It has also been used as a blowing agent and in some laboratory extraction procedures. Due to its properties, it is typically handled with appropriate ventilation and appropriate personal protective equipment to minimize inhalation and dermal exposure.

Safety and regulatory considerations are important with dichloromethane. It can act as a central nervous system depressant and may irritate the skin, eyes, and respiratory tract. Prolonged or high-level exposure can affect the liver and kidneys, and some health agencies classify it as a potential carcinogen, leading to restricted use in consumer products in many jurisdictions. Environmental and occupational exposure limits vary by country, reflecting concerns about toxicity and volatility.