It is not harmful to mix Freon with air. Freon in air mixtures generally uses R22, which is a non-toxic, odorless, non-flammable and non-explosive gas. However, exposure to open flames will produce phosgene, which is harmful to the human body. Once leaked, if there is no open flame, it will generally not cause harm to the human body. Freon, also known as Freon, its name comes from the English Freon is a refrigerant trademark registered by the American DuPont Company. There are differences in the definition of Freon in my country. It is generally defined as a general term for halogenated compounds of saturated hydrocarbons (mainly methane, ethane, and propane). According to this definition Freons can be divided into four categories: CFCs, HCFCs and HFCs. Some scholars define Freon as a CFC refrigerant; Freon only refers to dichlorodifluoromethane in some data. Freon is a colorless gas or volatile liquid at room temperature, tasteless or slightly odorless, non-toxic or low-toxic and chemically stable.