Use

EG is primarily used as a raw material in the manufacture of polyester fibers and fabric industry, 

and polyethylene terephthalate resins (PET) used in bottling. A small percent is also used in other 

applications such as antifreeze formulations and other products.
Dewatering agent
EG is used in the natural gas industry to remove water vapour from natural gas before further processing,

 in much the same manner as TEG (triethylene glycol).
Coolant and heat transfer agent
The major use of ethylene glycol is as a medium for convective heat transfer in, for example, 

automobiles and liquid cooled computers. Ethylene glycol is also commonly used in chilled water 

air conditioning systems that place either the chiller or air handlers outside, or systems that must 

cool below the freezing temperature of water. In geothermal heating/cooling systems, ethylene 

glycol is the fluid that transports heat through the use of a geothermal heat pump. The ethylene 

glycol either gains energy from the source (lake, ocean, water well) or dissipates heat to the sink, 

depending if the system is being used for heating or cooling.
Pure ethylene glycol has a specific heat capacity about one half that of water. So, while providing 

freeze protection and an increased boiling point, ethylene glycol lowers the specific heat capacity of 

water mixtures relative to pure water. A 50/50 mix by mass has a specific heat capacity of about 3140 J/kg C (0.75 BTU/lb F) 

three quarters that of pure water, thus requiring increased flow rates in same system comparisons with water. 

Additionally, the increase in boiling point over pure water inhibits nucleate boiling on heat transfer surfaces thus 

reducing heat transfer efficiency in some cases, such as gasoline engine cylinder wal

ls. Therefore, pure ethylene glycol should not be used as an engine coolant in most cases.
Antifreeze
Ethylene glycol disrupts hydrogen bonding when dissolved in water. Pure ethylene glycol freezes at 

about −12 °C (10.4 °F), but when mixed with water, the mixture does not readily crystallize, and 

therefore the freezing point of the mixture is depressed. Specifically, a mixture of 60% ethylene 

glycol and 40% water freezes at −45 °C (−49 °F).Diethylene glycol behaves similarly. It is used as 

a de-icing fluid for windshields and aircraft. The antifreeze capabilities of ethylene glycol have made

 it a component of vitrification (anticrystallization) mixtures for low-temperature preservation of biological tissues and organs.
However, the boiling point for aqueous ethylene glycol increases monotonically with increasing 

ethylene glycol percentage. Thus, the use of ethylene glycol not only depresses the freezing point, 

but also elevates the boiling point such that the operating range for the heat transfer fluid is 

broadened on both ends of the temperature scale. The increase in boiling temperature is due 

to pure ethylene glycol having a much higher boiling point and lower vapor pressure than pure 

water; there is no chemical stabilization against boiling of the liquid phase at intermediate compositions, 

as there is against freezing.
Precursor to polymers
In the plastics industry, ethylene glycol is an important precursor to polyester fibers and resins. 

Polyethylene terephthalate, used to make plastic bottles for soft drinks, is prepared from ethylene glycol.
Hydrate inhibition

Because of its high boiling point and affinity for water, ethylene glycol is a useful desiccant. 

Ethylene glycol is widely used to inhibit the formation of natural gas clathrates (hydrates) in 

long multiphase pipelines that convey natural gas from remote gas fields to a gas processing facility.

Ethylene glycol can be recovered from the natural gas and reused as an inhibitor after purification 

treatment that removes water and inorganic salts.
Natural gas is dehydrated by ethylene glycol. In this application, ethylene glycol flows down from the top 

of a tower and meets a rising mixture of water vapor and hydrocarbon gases. Dry gas exits from the top 

of the tower. The glycol and water are separated, and the glycol recycled. Instead of removing water, 

ethylene glycol can also be used to depress the temperature at which hydrates are formed. The purity 

of glycol used for hydrate suppression (monoethylene glycol) is typically around 80%, whereas the purity 

of glycol used for dehydration (triethylene glycol) is typically 95 to more than 99%. Moreover, the injection 

rate for hydrate suppression is much lower than the circulation rate in a glycol dehydration tower.
Niche applications
Minor uses of ethylene glycol include the manufacture of capacitors, as a chemical intermediate in the

 manufacture of 1,4-dioxane, and as an additive to prevent corrosion in liquid cooling systems for personal 

computers. Ethylene glycol is also used in the manufacture of some vaccines, but it is not itself present in 

these injections. It is used as a minor (1–2%) ingredient in shoe polish and also in some inks and dyes. 

Ethylene glycol has seen some use as a rot and fungal treatment for wood, both as a preventative and 

a treatment after the fact. It has been used in a few cases to treat partially rotted wooden objects to 

be displayed in museums. It is one of only a few treatments that are successful in dealing with rot in 

wooden boats, and is relatively cheap. Ethylene glycol may also be one of the minor ingredients in screen 

cleaning solutions, along with the main ingredient isopropyl alcohol. Ethylene glycol is commonly used as a 

preservative for biological specimens, especially in secondary schools during dissection as a safer alternative to 

formaldehyde. It can also be used in killing jars.It is also used as part of the water-based hydraulic fluid used to 

control subsea oil and gas production equipment.
Another interesting use is in the treatment of 'dry rot' or 'white rot' on timber joists, partially rotten or affected 

wood readily soaks it up and the fungus is subsequently killed. The main advantage of this type of treatment 

is that the glycol is hydroscopic and the wood being already water damaged readily absorbs a water based product.