Freon is the brand name of a Chlorofluorocarbon gas. It replaced other refrigerant chemicals that were more toxic or volatile, including ammonia. Throughout the 20th century, Freon became the dominant refrigerant gas.
The team that invented Freon was led by Thomas Midgley, Jr., who earlier had invented leaded gasoline. It was a joint venture between GM and DuPont, via a company called Kinetic Chemicals.
Eventually, scientists discovered Freon is incredibly environmentally destructive. The US and EU strongly discouraged the use of Freon in the late 1900s. They banned it in 2020. Midgley is arguably responsible for more environmental damage than any other single inventor.
While Freon was toxic to the environment it was largely non-toxic to human beings. There is little doubt that Midgley knew about the problems with lead but it remains less clear if he understood the problems with freon. To demonstrate the non-toxicity of Freon, Midgley once allegedly breathed it in then blew it onto a candle.
Like leaded gasoline, Midgley invented freon at Kettering Laboratories then licensed the patent to Frigidaire, then a division of General Motors.
