Organic Halide

Chlorofluorocarbons (CFCs) are compounds that contain both chlorine atoms and fluorine atoms bonded to carbon atoms. These compounds are very stable and are usually gases at room temperature. CFCs are often called Freons (trademark of E.I. du Pont de Nemours & Co.) because they are used in refrigerators and air conditioners. CFCs are also employed in the manufacture of various hard foams that are used under the siding in buildings and around dish washers and refrigerators for insulation and sound proofing. Since CFCs are excellent at dissolving oil and grease, they are a primary component of dry cleaning solutions. They are also used to remove oil and grease from electronic parts. The chlorofluorocarbon, dichlorodifluoromethane (CCl₂F₂), is not poisonous and is employed as the carrier gas in asthma and allergy inhalers. This compound is mixed with ethylene oxide, and the resulting gas is used to sterilize medical equipment and materials that are sent into outer space. In 1971, scientists determined that CFCs were accumulating in the atmosphere; they later showed that this "build up" was destroying the ozone layer, a level of the stratosphere that absorbs much of the harmful ultraviolet rays from the Sun. The Antarctic ozone hole was discovered in 1985, prompting the international community to sign the Montreal Protocol. The agreement between 24 nations limited the production of CFCs with the intention of ceasing production by the year 2000. The Protocol went into effect on January 1, 1989, and by July 1992, 81 countries had signed the agreement to save the ozone layer.