Engine Ice Hi-Performance Coolant is biodegradable, phosphate-free & non-toxic. The formula has shown excellent performance in all of the AS D 5216 (propylene glycol base engine coolant) tests. Also, it meets or exceeds all the corrosion performance requirements of AS d 3306 and SAE 4985 (the main specifications for premium ethylene glycol antifreeze). Plus it will not harm your seals or gaskets. Engine ice hi-performance cooler is the process of de-ionizing water that eliminates all of the impurities that can do harm to your cooling system. It can still contain minute particles of iron, magnesium, rust, lime, and calcium. Many of these waters also contain chemicals, such as chlorine, fluorides, and acids. Propylene glycol, the base fluid of Engine Ice Hi-Performance Coolant is far less toxic and safer for children, pets, and wildlife.