Antifreeze is used in a car's coolant. It is a special dope that has been added to the coolant, which ensures that the liquid does not freeze at a temperature of 0 degrees Celsius.
There are also meters in the garage where you can check whether the antifreeze content in the coolant is still OK. Since this decreases over the years, it is advisable to refresh the entire contents of the cooling system in the event of a negative result during the check. When using liquid without antifreeze (such as tap water) in the cooling system, there is a danger that if the water freezes and expands at 0 degrees (which it can quickly become in winter). This can tear the engine block. New coolant can withstand temperatures from -20 to -25 degrees Celsius. (Sometimes even lower).
Pure antifreeze is called 'Ethene Glycol, also known as Ethylene Glycol'. It is very harmful to health if you drink it. For adults, an amount of about 100 ml can already have deadly consequences.