The temperature of liquid propane is lower than minus 44 degrees Fahrenheit. If propane in liquid propane reaches minus 44 degrees Fahrenheit, it boils and transitions from a liquid into a vaporous state.
Propane is typically stored and transported in a liquid form. It is compressed inside a container and is released by a valve which allows it to vaporize. When it is in gas form, propane is odorless and tends to settle in low areas. Propane that is used commercially and in homes have an additional ingredient added that gives the gas an odor and allows leaks to be detected.