• Safer for people and pets.• Protects aluminum + all other engine metals.• Freeze-up and boil-over protection.• Phosphate free formula. Sierra® Antifreeze + Coolant is a premium automotive coolant that provides excellent engine protection in four key areas:• Freeze-up protection.• Boil-over protection.• Corrosion prevention.• Heat transfer. Sierra Antifreeze + Coolant meets all the requirements of ASTM D3306, the industry standard for propylene glycol coolants. Sierra's propylene glycol formulation makes it less toxic than conventional ethylene glycol based antifreeze, so it's safer for people, pets and wildlife in the environment. Sierra Antifreeze + Coolant reduces the risk of accidental poisoning resulting from spills, leaks or boil-overs. To achieve maximum benefits from Sierra Antifreeze + Coolant, be sure to flush the cooling system of all ethylene glycol based coolant. Even though Sierra is less toxic than conventional antifreeze, use with care. Clean up any leaks or spills. The Safer Antifreeze