Used primarily as an antifreeze agent in automotive cooling systems, it prevents engine freezing in winter and overheating in summer. It is a key raw material in the production of polyester fibers and polyethylene terephthalate (PET) used for plastic bottles and packaging. Also employed in the manufacture of resins, solvents, and heat transfer fluids in industrial systems. Its ability to lower the freezing point of water makes it valuable in deicing fluids for aircraft and in coolant mixtures for solar water heaters and HVAC systems.