1,1,1,2-Tetrafluoroethane

1,1,1,2-Tetrafluoroethane, also called simply tetrafluoroethane or R-134a, is a refrigerant that has zero ozone depletion potential and thermodynamic properties similar to R-12. It has the formula CH₂FCF₃.

1,1,1,2-Tetrafluoroethane is is an inert gas used primarily in automotive applications. In the United States, cars using R-134a refrigerant first appeared in model year 1995. It is also found in 'cans of air' used for blow-dusting computers and other miscellaneous items that are hard to reach or access. These cans contain tetrafluoroethane, rather than air, because tetrafluoroethane can be more easily compressed into a liquid than air, yielding more gas content per volume.

Contact of tetrafluoroethane with flames or hot surfaces (in excess of around 120 °F or 50 °C) may cause vapor decomposition and the emission of toxic gases.

Most spray cans when turned upside-down can become an effective freeze ray. When gases are compressed to liquid form, they become cold. So when a spray can filled with tetrafluoroethane is turned upside down and sprayed, it freezes whatever it touches.

Tetrafluoroethane is also poisonous.