Question

What do refrigerators emit that are harmful to the environment?

Answer 1

The substance which refrigerators emit that are harmful to the environment is CHLOROFLUOROCARBON, CFCs. 
Chlorofluorocarbon are harmful to the environment because they deplete the ozone layer which serve to protect humans from the dangerous effects of ultraviolet radiations. CFCs moves to the atmosphere where they are reduced to chlorine atom, these chlorine atoms attack the ozone layer and deplete it. <span />

Answer 2

Refrigerators let out chlorofluorocarbons (CFCs) that damages the ozone layer, while others are extremely potent greenhouse gases.