Ethylene glycol (EG) is a colorless, odorless, sweet-tasting viscous liquid with the chemical formula (CH₂OH)₂. It is the simplest diol, miscible with water, and is mainly used in the production of polyester fibers, antifreeze, solvents, and resins. While widely used, it is toxic to humans; large ingestions can be fatal.It is produced through the oxidation of ethylene, is highly reactive, and can undergo a variety of chemical reactions, making it an important chemical raw material. 

Physical properties

· Appearance : Colorless, odorless, sweet-tasting, viscous liquid.

· Solubility : Miscible with water, ethanol, acetone, etc., but has low solubility in ethers.

· Freezing point : It is hygroscopic and its freezing point will decrease when it is mixed with water to form a solution, but the freezing point will actually increase if the concentration is too high (above 60%). 

Chemical properties

· The molecule contains two hydroxyl groups, making it highly reactive and capable of undergoing esterification, etherification, oxidation, dehydration, and other reactions.

· It is easily oxidized to form glycolic acid, oxalic acid, etc., and preservatives need to be added to prevent corrosion. 

Main uses

· Polyester industry : It is the main raw material for the production of polyethylene terephthalate (PET), which is used to manufacture polyester, plastic bottles, films, etc.

· Antifreeze/coolant : lowers the freezing point of water and is widely used in automotive antifreeze and industrial cooling systems.

· Solvent : Used as a solvent in the dye, ink, resin and other industries.

· Other uses include manufacturing plasticizers, surfactants, adhesive wetting agents, explosives, and cosmetics.