HFC-134a is internationally recognized as one of the main refrigerant working substances to substitute CFC-12. It does not contain chlorine atom, gives no bad effects against ozonosphere and has excellent safety performances, such as non-inflammability, non-explosive ability, non-toxicity, non-pungency, and non-corrosive ability. It is a colorless gas under ordinary temperature and a colorless & transparent liquid under the pressure of itself. As the substitute for CFC-12, it is often used in the refrigerating systems of auto air conditioners, commercial and industrial purposes, and as the vesicant, it is used to produce the heat-protective material made of rigid plastics, and also to prepare other blend refrigerants, such as R404A & R407C.