Ethylene glycol is a colorless, slightly viscous liquid boiling point is 197.4 ℃, freezing point is -11.5 ℃, can be mixed with water in any proportion. Due to changes in the vapor pressure of the cooling water, the freezing point significantly reduced after mixing. Degree of reduction within a certain range with the content of the ethylene glycol increases. When the content of ethylene glycol was 60%, the freezing point can be lowered to -48.3 ℃, exceeds this limit, the freezing point but to rise. Glycol antifreeze easy to generate acidic substances in use, have a corrosive effect on metal. Glycol toxic, but because of its high boiling point, does not produce steam to be inhaled and cause poisoning. Ethylene glycol absorbent, storage containers should be sealed to prevent water absorption after overflow. Since the boiling point of water is lower than ethylene glycol, the use of evaporated water, when the lack of coolant, just add water on the line. This antifreeze can be recycled after use (to prevent mixing of petroleum products), through sedimentation, filtration, water was added to adjust the concentration, additional preservatives can continue to use, generally available 3--5 years. But many times you want to filter, to prevent damage to the vehicle. Many people think that a low freezing point of ethylene glycol, the freezing point of antifreeze is ethylene glycol and water mixed in different proportions according to a post and the freezing point, it is not true, due to changes in the mix after the cooling water vapor pressure, freezing point will significantly reduced. Degree of reduction within a certain range with increasing ethylene glycol content decreased, but once more than a certain proportion of the freezing point it will rise. 40% of ethylene glycol and 60% of soft water mixed into antifreeze, the antifreeze temperature is -25 ℃; when ethylene glycol antifreeze and water accounting for 50%, the freezing temperature of -35 ℃. [6]