Any substance that lowers the freezing point of water , protecting a system from the ill effects of ice formation.
Antifreezes such as ethylene glycol or propylene glycol commonly added to water in automobile cooling systems prevent damage to radiators. Additives to prevent freezing of water in gasoline (e.g., Drygas) usually contain methanol or isopropanol. Organisms that must survive freezing temperatures use various chemicals to inhibit ice crystal formation in their cells and tissues: glycerol or nematode s, rotifer s), and protein s in Antarctic fishes.