Claim: One of the four liquid gases listed is CCl2F2, a colorless gas used as aerosol spray propellant.
Evidence: Examples of liquefied gases include liquid air, liquefied natural gas, and liquefied petroleum gas. Chlorotrifluoromethane, R-13, CFC-13, or Freon 13, is a non-flammable, non-corrosive chlorofluorocarbon (CFC) and also a mixed halomethane.