What's Free About It?

Freon (/ friːɒn /) è un marchio registrato di The Chemours Company,

Freon (/ˈfriːɒn/) is a registered trademark of The Chemours Company, which uses it for a number of halocarbon products. They are stable, nonflammable, moderately toxic gases or liquids which have typically been used as refrigerants and as aerosol propellants. These include the chlorofluorocarbons (CFCs) that cause ozone depletion (such as chlorodifluoromethane), but also include newer refrigerants which typically include fluorine instead of chlorine and do not deplete the ozone layer. Not all refrigerants of this type are labelled as "Freon" since Freon is a brand name for the refrigerants R-12, R-13B1, R-22, R-502, and R-503 manufactured by The Chemours Company.

*wikipedia

The term "freon" is a common descriptor or proprietary eponym like "coke," "xerox," or "kleenex." It is commonly used when referring to any fluorocarbon refrigerants.