Basic Properties

• Isopropyl belongs to the larger chemical class of compounds known as alcohols. This entire class of hydrocarbons is known for having very low freezing point temperatures of -100 degrees Fahrenheit or less.
  
  

Freezing Point of Isopropyl

• The freezing point of isopropyl alcohol is --127.3 degrees Fahrenheit, --88.5 degrees Celsius or 184.7 Kelvin.
  
  

Use as an Additive

• Isopropyl alcohol is used as a freeze-resistant fuel line additive because it lowers the freezing temperatures of liquids it is added to. It is this same property that is responsible for the freezing point of sea water having a lower freezing point than pure water, around '5.9 degrees Celsius for a 10 percent concentration of salt.