Ethylene Glycol (IUPAC name: ethane-1,2-diol) is an odourless, colourless, sweet-tasting, organic compound with the formula (CH2OH)2 and is mostly used as a raw material in the manufacture of polyester fibres and for antifreeze and de-icing solutions for cars, airplanes, airport runways, and boats.
Ethylene glycol is also used as a preservative for biological specimens, especially in high schools during dissection as a safer alternative to formaldehyde, and as part of the water-based hydraulic fluid used to control subsea oil and gas production equipment.
Pure water freezes at 0 degrees Celsius (32 F) and pure ethylene glycol freezes at -12.9 C (8.9 F). The low freezing points of glycol mixtures make them ideal for cooling items below the freezing point of water.
Thus, glycol/water mixtures are often used to cool freezers and similar environments. 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
A mixture of ethylene glycol with water provides additional benefits to coolant and antifreeze solutions, such as preventing corrosion and acid degradation, as well as inhibiting the growth of most microbes and fungi.
Ethylene glycol is moderately toxic and since consumer products such as antifreeze, brake fluids, inks, plastics, and textiles often contain Ethylene Glycol there is a risk of exposure.
The major danger is due to its sweet taste, which can attract children and animals. Household pets are especially susceptible to ethylene glycol poisoning from vehicle antifreeze leaks. Upon ingestion, ethylene glycol is oxidized to glycolic acid, which is, in turn, oxidized to oxalic acid, which is toxic. It and its toxic by-products first affect the central nervous system, then the heart, and finally the kidneys.
Ingestion of large amounts is fatal if untreated. It is therefore important for those in contact with products or handling chemicals containing Ethylene Glycol to wash their hands thoroughly and for those who have accidentally ingested it to seek medical attention immediately.