They are used in installations operating at low temperatures, for cooling internal combustion engines, as aviation anti-icing fluids and as a glass cleaner. Mixtures of ethylene glycol, propylene glycol, glycerin, monohydric alcohols and other substances with water are used as antifreeze base fluids. Antifreezes go on sale both in the form ready for use in the cooling system, and in the form of a concentrate, which the consumer needs to dilute with water, preferably distilled or deionized. Ethylene glycol coolants of different grades differ from each other by and large only in the percentage ratio between water and ethylene glycol, which determines the temperature of the onset of crystallization, as well as in the composition of the additive package. However, the quality of raw materials also plays a role - in particular, the degree of purity of water (distilled, deionized, ordinary tap, etc.) and the quality of ethylene glycol purification.