Ethylene glycol is primarily used in antifreeze formulations (50%) and as a raw material in the manufacture of polyesters such as polyethylene terephthalate (PET) (40%).

Ethylene glycol solutions became available in 1926 and were marketed as "permanent antifreeze" since the higher boiling points provided advantages for summertime use as well as during cold weather. They are used today for a variety of applications, including automobiles.

Because of the depressed freezing temperatures, ethylene glycol is used as a de-icing fluid for windshields and aircraft, as an antifreeze in automobile engines, and as a component of vitrification (anticrystallization) mixtures for low-temperature preservation of biological tissues and organs. The mixture of ethylene glycol and water can also be chemically termed as glycol concentrate/compound/mixture/solution.

The use of ethylene glycol not only depresses the freezing point of aqueous mixtures but also elevates their boiling point. This results in the operating temperature range for heat-transfer fluids being broadened on both ends of the temperature scale.

Ethylene glycol has a bitter, sweet taste and causes inebriation. The toxic effects of ingesting ethylene glycol occur because it is converted by the liver into 4 other chemicals that are much more toxic and in high doses it is lethal.

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