CCl₂F₂, This compound, also known as Freon^® 12 or CFC-12, is the primary CFC that has been linked to the catalytic destruction of ozone. Even though the compound is found in very small concentrations, its properties make it a significant factor in stratospheric chemistry. CCl₂F₂ absorbs UV light in the upper stratosphere where it arrives decades after being released in the troposphere. CFCs, which were originally created by Dupont corporation, were used as refrigerants for everything from air conditioning to home refrigerators because they are non-toxic and extremely unreactive (in the troposphere). It is this unreactivity that makes them such a problem for the atmosphere, because they are able to last long enough to make it to the stratosphere, where they cause so many problems. CCl₂F₂ production, along with all CFCs, has been banned since the mid 1990s, but some scientists believe that the damage has already been done. For further reading see the term ozone.