Dichloromethane, also known as methylene chloride or DCM for short, is a colorless organic compound with an ether-like pungent odor and the chemical formula CH?Cl?. This compound is formed by replacing two hydrogen atoms in methane (CH?) with chlorine atoms. It is slightly soluble in water and soluble in ethanol. Under normal conditions of use, it is a non-flammable low-boiling-point solvent. Its vapor can form a weakly combustible gas mixture only when present in high concentrations in high-temperature air^[1]. It is often used as a substitute for flammable solvents like petroleum ether^[2]. With excellent solubility, it is widely applied in industrial fields such as industrial solvents, intermediates, and refrigerants. It also plays a significant role in pharmaceutical preparation, laboratories, and the pharmaceutical industry.