Before revision: As a result of CFCs contributing to ozone depletion in the upper atmosphere , the manufacture of such compounds has been phased out under the Montreal Protocol, and they are being replaced with other products such as hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) including R-410A,R-134a and R-1234yf.
After revision: As a result of CFCs contributing to ozone depletion in the upper monnnnnatmosphere , the manufacture of such compounds has been phased out under the Montreal Protocol, and they are being replaced with other products such as hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) including R-410A,R-134a and R-1234yf.