Diethylene Glycol (DEG) is a colorless, hygroscopic, slightly viscous liquid with a mild, sweet odor. With the chemical formula C₄H₁₀O₃, it is commonly used as a solvent, humectant, and intermediate in the manufacture of resins, plasticizers, and polyurethanes. DEG is miscible with water, alcohols, ethers, and acetone, making it a versatile solvent in industries such as paints and coatings, cosmetics, textiles, antifreeze, and brake fluids. It is also used in the production of unsaturated polyester resins and as a dehydrating agent.