CFC

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__Abstract__

I am very concerned with my environment and the affect that polution has on it. After doing my research on cfc in the environment, i was extremely relieved to find that they chemicals had been banned and that there were some alternatives available.

Most people have already updated their air conditioning units but if you haven't the preferred alternative is to retrofit your AC system to HFC-134a(hydroflourocarbons). Such a retrofit entails changing several mechanical parts of the AC. The parts per unit start at roughly $250. The ozone layer protects us from the sun. Without it we would be prone to sunburns, cataracs, and skin cancer. It will also be extremely harmful for animals, presenting problems such as skin diseases, and melt ice for polar bears. The United Nations needs to realize how dangerous these chemicals are and the only way we will prevent this from happening is if they ban them from all countries.

I am very concerned with my environment and the affect that polution has on it. After doing my research on cfc in the environment, i was extremely relieved to find that they chemicals had been banned and that there were some alternatives available.

__Background__ Chloroflourocarbons were discovered in the 1920's by Thomas Midgley, an organic chemist at General Motors Corporation. He was looking for inert, non-toxic, non-flammable compounds with low boiling points that could be used as refrigerants.

Chloroflourocarbons are greenhouse gasses which contributes approximately 24% to global warming. The source of these gases is leaking air conditioners, refrigerators, industrial solvents, production of plastic foam, and aerosol propellants. Chloroflourocarbons were banned in 1997, However, the deadline in third world countries was even later. But even if CFC's and other ozone-depleting substances had been banned immediately, scientists say it still would have taken from 75 to 100 years for the ozone layer to fully recover.

__Synthesis/Production__ -CCl2F 2 + UV (< 220nm) => Cl + CClF2 -Cl + O3 => ClO + O2 -ClO + O => Cl + O2 CFC's are made through the bondage of chlorine and fluorine atoms CFC's are dangerous when they come in contact with the sunlight and the chlorines break off and enter our environment and it damages the ozone layer

__Economic/Political__ studies estimated that the ozone layer would be depleted by CFC's by about 7% within 60yrs and based on such studies the US banned CFC's in aerosol sprays in 1978. Slowly various nations agreed to ban CFC's in aerosols but industry fought the banning of valuable CFC's in other applications.

Attempts have been made to develop compounds which have low ozone depletion potential (ODP) to replace CFCs as refrigerants, aerosol propellants and solvents. Possible alternatives for CFCs include:

-Hydrochlorofluorocarbons (HCHCs) such as CF3CHCl2 They break down more quickly in the atmosphere. Though they have a lower percentage of chlorine and hence a lower ozone depletion potential than CFCs, they could damage ozone if overuse. -Hydrofluorocarbons(HCFs) such as CF3CH2F They have no chlorine and thus are "ozone safe". However, safety question on toxicity is still unsolved. -Hydrocarbons such as butane and propane They are cheap and readily available. As they contain no chlorine, they are "ozone safe". However, they are flammable and poisonous. -Water and steam They are effective for some cleaning applications and thus can replace some CFCs as solvents in cleaning.

Most people have updated their air conditioning units but if you haven't the preferred alternative is to retrofit your AC system to HFC-134a(hydroflourocarbons). Such a retrofit entails changing several mechanical parts of the AC and the price starts at $250

If they had banned CFC's without being able to find a suitable replacement we would lost aerosol propellants such as paint, insecticide or cosmetic preparations in pressurized canisters.

The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of a number of substances believed to be responsible for ozone depletion, laid out by the united nations.

__Human Health__ The ozone layer protects us from the sun. Without it we would be prone to sunburns, cataracs, and skin cancer. It will also be extremely harmful for animals, presenting problems such as skin diseases, and melt ice for polar bears.

__Environmental__ studies estimated that the ozone layer would be depleted by CFC's by about 7% within 60yrs and based on such studies the US banned CFC's in aerosol sprays in 1978.

__Summary__ laws have already been created to eliminate CFC's out of the environment. For example it cost roughly 250 dollars to update each air conditioning unit. However, there are still many things needed to be done. The laws in placed are more of guidelines, instead of strict laws that are to be enforced. And countries are slowly taking CFC's out of their products. However, with the amount of damage they are doing to the environment, much more action is required.

Pictures http://www.flickr.com/photos/kukuphoto/1371922328/ http://www.fao.org/docrep/003/t0756e/T0756E51.jpg http://www.topnews.in/health/files/Skin-diseases.jpg

Information Human Health, Economic Crisis, Environmental, Human Health [] Laws of CFC []