Global Warming and Chlorofluorocarbons (CFCs)
Chlorofluorocarbons are non-toxic, non-flammable chemicals that are mainly used in the manufacturing of aerosols, blowing agents for foams and packing materials, as solvents, and as refrigerants. They are classified as Halocarbons, a class of compounds that contain carbon and halogen atoms, and are amongst a group of substances called “greenhouse gases”. They eat away at our ozone and raise the temperature of our planet significantly, causing detrimental damage to our planet.
Chlorofluorocarbons (CFC’s) are a man-made substance that did not previously exist to the industrial area. They are a product of a collaboration of three American companies – Frigidaire, General Motors, and Du Pont -- after a series of fatal accidents during the 1920’s where toxic gases, (Methyl Chloride), used as refrigerants leaked from refrigerators. Thomas Midgley, Jr. of General Motors first synthesized CFC’s in 1928, and later, on December 31, 1928, Frigidaire was issued the first patent for this formula. CFC’s went under the trade name of Freon (11 and 12), licensed by Du Pont, and by 1935, they and their competitors had sold over eight million new refrigerators in the United States containing the substance. Because of the CFC safety record for non-toxicity, especially when compared to that of previously used substances for coolants, Freon became the preferred substance in large air-conditioning systems. Public health codes in many American cities were even revised to mandate the use of Freon. Soon thereafter the production and use of CFC’s took off, ranging from propellants for bug sprays, paints, hair conditioners, and in air-conditioning in automobiles. (See appendices 1) Peak annual sales of the product worldwide reached over one billion dollars US, and more then one million metric tons were produced.
CFC’s at ground level are perfectly safe, being inert at lower atmospheric levels, but they do undergo a significant reaction in the upper atmosphere or stratosphere. The first proof of this was in 1974 when a study by two university professors showed that CFC’s went through a process called “Photolytic Decomposition” (see appendices 2) thereby releasing chlorine atoms into the atmosphere where they would become active in the destruction of the Ozone. A loss of the stratospheric ozone would result in higher levels of ha...
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...of CO2), they have a much shorter life span, of about 13 years. The Copenhagen Amendment calls for their elimination by 2020. The HFC’s are considered to be the best substitute to CFC’s, as they do not contain chlorine (the substance that destroys ozone), their inability to trap heat and their short lifespan. In America, all new air conditioners in automobiles contain HFC’s, and their rate of use is growing rapidly, at a rate of 100% a year.
After nearly a century of use, CFC’s have finally been almost totally eliminated from production on the face of the planet. It seems as though we have finally taken a step in the right direction as far as preserving our ozone and our climate. Unfortunately, the repercussions of CFC’s will not go away anytime in the near future. Their effects will be felt well into the next century, as they continue to eat up what remains of our ozone and heat up our planet. Even after all of the CFC’s have decomposed, it will take generations before the ozone can begin to regenerate. That is one positive aspect of all this, and our future depends on it -- the damage done today is not irreversible -- but without immediate and drastic action, it will be.
Halons have been tested to be harmful to the Earth’s stratospheric ozone layer which makes the global warming potential unacceptable. The United States has banned import halon production on Jan 1...
...Greenhouse gases are of global concern because they enhance global warming, which can alter many ecosystems such as in the Arctic and Sub-Arctic (BBC, 2009). Other gases such as carbon monoxide formed by the incomplete combustion of hydrocarbons will also be emitted and the inhalation of such gases can cause death of human beings and other organisms by depleting the oxygen supply in the affected organism (USFA, 2009)
CFCs were invented in Dayton, Ohio, in 1928. They were the product of an intensive search by engineers with the G. M. Research Corporation to find a safe, non-toxic, non-flammable refrigerant. Frigidaire patented the formula for CFCs in 1928 and the "new wonder gas" was named Freon. Seth Cagin and Phillip Dray, co-authors of Between Earth and Sky, inform us in their story of CFCs that "Freon soon topped the list of wonders, a 'miracle' refrigerant . . . [with the] combination of safety, cleanliness, and efficiency . . . " (66). Not only was the apparently "safe" gas being used in refrigeration, but with the innovation of air-conditioning by Willis Carrier prior to World War I, Freon would one day be used to cool our homes, automobiles, and businesses.
In the GE and CFC case, it would have been practically impossible for engineers in the 1930s to quantify the damage in monetary terms of CFC, even if they had perceived the potential future ecological issues
Hairspray. Refrigerators. Air conditioners. These everyday luxuries, while making human life more comfortable, are taxing our health seriously. Clorofluorocarbons, or CFCs, are anthropogenic chemicals used in refrigerants and as propellants in aerosols. CFCs, also known as freons, are also the primary culprit behind the depletion of stratospheric ozone, which allows harmful ultraviolet rays to reach the Earth and its inhabitants.
Rowland and Mario Molina proposed that CFC emissions would lead to the destruction of the stratospheric ozone layer2. At that time Drs. Rowland and Molina suggested that
From the day-to-day use of CFC’s (Chloro fluoro carbons) and other depletion substances the ozone wears off more and more. These substances are referred to as ozone-depleting substances (ODS). They are usually found in chemicals and as a result of causing depletion in the ozone layer, cause skin cancer and disorder in humans and animals as well. CFC’s are used as coolers in refrigerators, and air conditioners. They used to be used in car air conditioners until 1995, when it was discovered the CFS’s were depleting the ozone. Industrially, they are found in solvents and sometimes in dry cleaning agents. Furthermore, cleaning agents, foam insulation and packaging materials are also known to aid in the ozone depletion.
A thin layer of gas called atmosphere surrounds the Earth. The atmosphere serves two important purposes: it is a filter for the suns dangerous ultraviolet radiation rays and keeps the heat, necessary to maintain life on earth, within the stratosphere (Vorlat 361). Ultraviolet light is incredibly dangerous to all the organisms within the Earth's ecosystem because it causes skin cancer, effects the immune system, and harms plant and animal life. For that reason the atmosphere and the ozone layer within it are crucial to a stable life on this planet. The ozone layer is in danger, however. It is facing depletion by a toxic man-made substance called chlorofluorocarbons (CFCs). Together the international community is working through treaties and conventions to stop this environmental problem.
15.2) The accumulation of chlorofluorocarbons is responsible for depleting the atmospheric zone. The atmospheric zone has changed in concentration due to human activity. The CFCs release chlorine atoms which react with ozone reducing it to molecular O₂. Following chemical reactions release the chlorine which reacts with other ozone molecules in a catalytic chain reaction. The ozone layer is getting thinner and thinner as stable air at places such as Antarctica allows reaction to continue. The accumulation of CFCs has led to increased UV radiation in sunlight reaching the earth thereby decreasing ozone levels. The global temperature has increased.
The original self-contained refrigerators used sulfur dioxide as a coolant. Sulfur dioxide, being highly toxic, resulted in the occasional death due to refrigerator malfunction. Subsequently, the search for a cheap and non-toxic replacement began. General Motors sought out Thomas Midgley Jr., a world-renowned chemist at the time, and requested that he pursue research into possible alternative coolants. Midgley’s research led him to consider carbon tetrafluoride and dichlorodifluoromethane.2 Both possessed stability, a non-reactive nature, and fire extinguishing characteristics, but dichlorodifluoromethane was nominated as the preferable option because its boiling point was better suited to the mechanics of refrigerators. This new co...
follows: (How do CFCs Destroy the Ozone) Cl + O3 -----> ClO + O2 ClO + O
The stratospheric ozone layer is the Earth's natural means of protection from the Sun's damaging ultraviolet rays. Some of the chemicals most harmful to the ozone layer are chlorofluorocarbons, or CFCs. These compounds are chemically inert gasses that, when introduced to the stratosphere, speed up the depletion of the ozone layer. The reason that these chemicals are so harmful is that after a CFC molecule is broken up by UV radiation in the stratosphere, its Chlorine atom is free to react with the ozone molecules in the atmosphere. Because Chlorine is a catalyst, it continues to react with other ozone molecules causing continuous damage and depletion of the ozone, as can be seen from the chart of CFC reactions below.
The factors for exponential growth for air-conditioning are the HVAC Market, energy, environment, communication, societal, political, preparing for the future, looking ahead, and the conclusion. Buildings of the U.S. use approximately 35% of the nation’s precise total of energy consumption. The worth of shipments by U.S. HVAC manufacturers was over $28 billion of 1996. Since there are 52,000 CHC chillers needed to be replaced among the U.S., there’s a large opportunity for new chillers, new technology for the HVAC industry. The ozone depletion is an international issue in which is currently being resolved. The 3rd world countries are still allowed to manufacture CFC’s. Illegal imports of CFC’S to the U.S. is a consistent concern. Many illegal imports are virgin CFC’s. Those whom have a political overtones are specifically the ones whom create a protectionism of local commerce, having a negative impact on those inside and out of the country.
Elaborar una estrategia comunitaria para la eliminación de los clorofluorocarbonos (CFC) de los inhaladores - dosificadores.
society today. The CFC cans used to be a serious problem to the ozone layer,