The ozone layer is a dense layer of ozone (O3) in the upper layer of the atmosphere. It absorbs harmful ultraviolet rays contained in sunlight and plays a role in protecting the life of the earth.
In the 1970s and 80s, it was discovered that the ozone layer over Antarctica was destroyed and a hole (ozone hole) was created. When destruction progresses, strong ultraviolet rays reach the surface of the earth without being absorbed by the ozone layer, causing skin cancer and adversely affecting the ecosystem.
So why has the ozone layer been destroyed? In fact, it was pointed out that the cause was cfc-based refrigerant, which is one kind of refrigerant used in many applications, such as air conditioners, refrigerator refrigerants, spray propellants, and printed circuit boards. Ozone depletion was caused by chlorine contained in CFC refrigerant seboteuring ozone.
It was because of this ozone layer destruction that the refrigerant became a big social problem originally. Since then, CFC refrigerant has been replaced by HFC refrigerant as an alternative refrigerant.
However, it was found that the HFC-based refrigerant was a global warming substance, and it was found that there was a greenhouse effect of thousands of times the carbon dioxide. Therefore, the problem of the refrigerant is a global warming problem now.
From Hyogo Prefecture Freon Recovery and Processing Promotion Council Website