Refregerator gases used to leak out and kill people and people tried to replace them with safer chemicals

https://www.youtube.com/watch?v=SC2eSujzrUY

How One Company Secretly Poisoned The Planet

Veritasium

Youtube

https://en.wikipedia.org/wiki/Polytetrafluoroethylene

Polytetrafluoroethylene

https://en.wikipedia.org/wiki/Uranium_hexafluoride

Uranium hexafluoride, sometimes called hex