The Problem

• The EPA estimates that only about 12 percent of old antifreeze is recycled every year. The rest is discharged into the environment, a practice that has sweeping public health and biological consequences, according to a report by a team of researchers at the University of New Mexico on heat pump antifreeze.
  
  

Types of Antifreeze Pollution

• The four most common types of antifreeze, according to the UNM study, are methanol, ethanol, propylene glycol and potassium acetate --- in that order. When used, numerous other heavy metals also appear.
  
  

Methanol the Best?

• Though the most common antifreeze, methanol has a higher risk of fire, health implications and environmental risks than the others. Propylene glycol and potassium acetate, by comparison, pose lower risks for pollution but are more expensive too.