Star brite Boiler System Antifreeze is a an ethanol-free, safe, odorless, tasteless and non-flammable premium hydronic heating and cooling system fluid. Made from virgin propylene glycol (PG), this heat transfer fluid contains premium corrosion inhibitors to protect internal components. It's formulated to have a high specific heat and boiling point and provides burst protection down to -100 degree Fahrenheit at full strength. Works in Aqua-Hot and Hydro-Hot systems as a heat transfer fluid and is perfect for use in traditional boilers, closed boilers and solar systems. This makes Star brite's Boiler System Antifreeze an ideal choice for consumers looking for a safer, environmentally friendlier solution, in case of overflows, leaks and spills.