Scientists first proposed the theory of ozone depletion by cfcs in 1974. They were much used in the middle 20th century, replacing chemicals that were toxic or flammable or had other problems. What effects do chlorofluorocarbons have on humans. They are used in aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants. Chlorofluorocarbon article about chlorofluorocarbon by. Chlorofluorocarbons cfcs and hydrochlorofluorocarbons hcfcs are fully or partly.
A company registered in and regulated by a foreign country that has at least 50% american ownership. The agencys statute was approved on 23 october 1956 by the conference on the statute of the iaea held at united nations headquarters, new york. An example is cfc12 ccl2f2, used as a refrigerant in refrigerators and air conditioners and as a foam blowing agent. The government is encouraging the phaseout by mandating reduced produc tion levels and levying taxes on cfc production. Cfcs are classified as halocarbons, a class of compounds that contain atoms of carbon and halogen atoms. Organic compounds made up of atoms of carbon, chlorine cl 2, and fluorine f 2. These three elements are produced from propane, ethane, and methane as volatile derivative. Compounds of chlorine and fluorine once much used as aerosol propellants. When cfcs also contain hydrogen in place of one or more chlorines, they are called hydrochlorofluorocarbons, or hcfcs. In 1990, 93 nations agreed, as part of the montreal protocol established 1987, to end production of ozonedepleting chemicals by the end of the 20th century. Stipub1238 isbn 9208058 includes bibliographical references.
Chlorofluorocarbon definition is any of several simple gaseous compounds that contain carbon, chlorine, fluorine, and sometimes hydrogen, that are used as refrigerants, cleaning solvents, and aerosol propellants and in the manufacture of plastic foams, and that are believed to be a major cause of stratospheric ozone depletion abbreviation cfc. The environmental impact of chlorofluorocarbon use in metered dose inhalers article pdf available in chest 1004. Chlorofluorocarbons cfcs are hydrocarbons, such as freon, in which some or all of the hydrogen atoms have been replaced by fluorine atoms. May 11, 2018 chlorofluorocarbons, commonly abbreviated as cfcs, are paraffin hydrocarbons that are fully halogenated. Definition of environment environment french word environ surroundings. Chlorofluorocarbons, commonly abbreviated as cfcs, are paraffin hydrocarbons that are fully halogenated. Rabin ast october, prime news coverage fo cused once again on chlorofluorocarbons cfcs, a chemical substance suspected to cause an especially. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Chlorofluorocarbon definition and meaning collins english. Pdf the environmental impact of chlorofluorocarbon use. Sherwood rowland and mario molina and dutch chemist paul crutzen, indicated that cfcs, once released into the atmosphere, accumulate in the stratosphere, where they contribute to the depletion of the ozone layer. Cfcs or chlorofluorocarbons are organic compounds that found large scale application in refrigerants few decades ago.
May 31, 2017 chlorofluorocarbons cfcs are a group of odorless manufactured chemicals. An example is cfc12 ccl 2 f 2, used as a refrigerant in refrigerators and air conditioners and as a foam blowing agent. They could also be found in refrigerants in air conditioners and refrigerators. Cfcs the cfc program monitors the emissions of ozonedepleting compounds, chlorofluorocarbons and hydrofluorocarbons through an inspection and compliance program. Chlorofluorocarbons are the worst invention of the 20th century. Chlorofluorocarbons and ozone depletion answer guide. Environmental protection act 1986 defined environment as the sum total of water, air and land, their interrelationship among themselves. Because of a growing concern over stratospheric ozone depletion and its attendant dangers, a ban was imposed on the use of cfcs in aerosolspray dispensers in the late 1970s by the united states, canada, and the scandinavian countries. In 1978, sweden became the first country that banned cfc products. Cfcs are particularly harmful when released into the atmosphere because of their destructive reaction with ozone particles, which provide the earth with a protective layer against uv radiation. Cfcs has other important implications for the global environment. They said chlorofluorocarbon gas, which is used mostly in air conditioning and refrigeration, heating and other equipment operating under pressure gas systems, is a chemical toxic gas and is harmful to health as it can cause skin cancer and some respiratory diseases and is.
The main molecules that are destroying the ozone layer are called chlorofluorocarbons or cfcs. Cfcs have been used as refrigerants, propellants in aerosols, metal degreasers, i n fire extinguishers, and as a dry cleaning solvent. Chlorofluorocarbons cfc are gases used for various purposes including solvents,refrigerants and aerosol sprays. Chlorofluorocarbon cfc, any of several organic compounds composed of carbon, fluorine, and chlorine. Pdf globally, the production of cold housing is seen as a major energy challenge. Chlorofluorocarbons epa glossary of climate change terms organic compounds made up of atoms of carbon, chlorine, and fluorine. Chlorofluorocarbon definition of chlorofluorocarbon at. Chlorofluorocarbon cfcs chlorofluorocarbons are found in aerosol cans and fridges. Feasibility of groundwater dating by cfcs was assessed comprehensively based on the concentrations of no3. A special numbering system is to be used for fluorinated alkanes, prefixed with freon, r, cfc and hcfc, where the rightmost value indicates the number of fluorine atoms, the next value to the left is the number of hydrogen atoms plus 1, and the next value to the left is the number of carbon atoms less one zeroes are not stated, and the remaining atoms are chlorine. Esrl global monitoring laboratory halocarbons and other. Chlorofluorocarbons and the ozone layer semantic scholar. This causes the ozone to break up and become unable to absorb ultraviolet light.
Chlorofluorocarbon financial definition of chlorofluorocarbon. Jun 27, 2019 chlorofluorocarbons are chemical compounds that were developed commercially in the 1930s by dupont. Before cfcs products were banned, they were used in aerosols, refrigerators, air conditioners, foam food packaging, and fire extinguishers. An environmental legacy of the twentieth century is the use of gaseous compounds called chlorofluorocarbons cfcs, which are also known as freon in a variety of household and personal products. Department of the environment and heritage australian chlorofluorocarbon management strategy page 3 a message from the secretary depletion of the ozone layer is a major environmental concern both nationally and internationally. Chlorofluorocarbon definition, any of several volatile, inert, saturated compounds of carbon, fluorine, chlorine, and hydrogen. Hcfc, hydrochlorofluorocarbon a fluorocarbon that is replacing chlorofluorocarbon as a refrigerant and propellant in aerosol cans. Apr 26, 2017 how do chlorofluorocarbons affect the environment. Chlorofluorocarbons and the environment practice khan academy. The montreal protocol was a global agreement developed to stop this harmful ozone destruction. Chlorofluorocarbons definition of chlorofluorocarbons by.
Gaseous cfcs can deplete the ozone layer when they slowly rise into the stratosphere, are broken down by strong ultraviolet radiation, release chlorine atoms, and then react with ozone molecules. Chlorofluorocarbons cfcs were commonly used as aerosol spray can propellants. Chlorofluorocarbon rate noun cfcs chlorofluorocarbons are found in aerosol cans and fridges. Dec 20, 20 to delineate the groundwater flow system in a basin, the groundwater age was estimated by analyzing chlorofluorocarbons cfc11, cfc12 and cfc1 in a typical headwater wetland in ichikawa, japan. Chlorofluorocarbons cfcs and hydrochlorofluorocarbons hcfcs are fully or partly halogenated paraffin hydrocarbons that contain only carbon c, hydrogen h, chlorine cl, and fluorine f, produced as volatile derivative of methane, ethane, and propane.
Cfcs can be liquids or gases, are nonflammable and heatstable, and are used as refrigerants, aerosol propellants such as in deodorant, whipped cream. Nov 01, 2017 the montreal protocol was a global agreement developed to stop this harmful ozone destruction. The protocol mandated a time frame to completely abolish cfcs. Cfc any of various halocarbon compounds consisting of carbon, hydrogen, chlorine, and fluorine, once used widely as aerosol propellants and refrigerants. Because they damage the earths ozone layer, cfcs have been banned since 1996. Setting up a corporation in a foreign country may have tax advantages. Use of chlorofluorocarbons in hydrology a guidebook 2005 edition. However, it was found out that cfcs react with the ozone gas in our atmosphere.
Chlorofluorocarbons environment definition,meaning. Gasses covered under the 1987 montreal protocol and utilized for refrigeration, ventilating, bundling, insulation, solvents, or aeroslo propellants. Cfcs have become discredited because of their effect on. It turns out that certain types of molecules can cause a chemical reaction when they come in contact with ozone molecules. They said chlorofluorocarbon gas, which is used mostly in air conditioning and refrigeration, heating and other equipment operating under pressure gas systems, is a chemical toxic gas and is harmful to health as it can cause skin cancer and some respiratory diseases and is harmful to the environment and the ozone layer. They are organic chemicals and contain carbon, sometimes hydrogen, chlorine, and fluorine. Cfcs have become discredited because of their effect on the ozone layer. Chlorofluorocarbons cfcs are a group of odorless manufactured chemicals. Chlorofluorocarbon definition of chlorofluorocarbon by. The hitran 2008 molecular spectroscopic database pdf. Chlorofluorocarbons list of high impact articles ppts.
Pdf a b s t r a c t to establish a proper regulation strategy on the emissions of major. Environmental protection agency issued final regulations that implement the montreal protocol on substances that deplete the ozone layer. Volatile chlorofluorocarbons are believed to cause depletion of the atmospheric ozone layer. Chlorofluorocarbons, commonly referred to as cfcs, are noncombustible liquids that were, at one time, frequently used as refrigerants and aerosol propellants, as well as for cleaning products. An example is cfc12 ccl2f2, used as a refrigerant in refrigerators and air conditioners and as a foam blowing agent chlorofluorocarbons are fully halogenated paraffin hydrocarbons that contain only carbon, chlorine cl, and fluorine f, produced as volatile. For example, the emission rates of hcfc22, hfc4a, and. To delineate the groundwater flow system in a basin, the groundwater age was estimated by analyzing chlorofluorocarbons cfc11, cfc12 and cfc1 in a typical headwater wetland in ichikawa, japan. Environmental regulations on chlorofluorocarbons springerlink. Unfortunately, the inertness of these compounds allows them to persist in the environment for long. Excellent summaries of theory and application of a wide range of environmental tracers.
Cfcs are highly effective refrigerants that were developed in response to the pressing need to eliminate toxic and flammable substances, such as sulfur dioxide and ammonia, in refrigeration units and air conditioners. Cfc11 in order to protect the environment against their ozone depletion potential. Pdf refrigerants and their environmental impact substitution of. Cfcs are particularly harmful when released into the atmosphere because of their destructive reaction with ozone particles, which provide the earth with a. Chlorofluorocarbon definition in the cambridge english. A range of compounds, composed of chlorine, fluorine, carbon and hydrogen, used as aerosol propellants and refrigerants. Chlorofluorocarbons are chemical compounds that were developed commercially in the 1930s by dupont. Application of chlorofluorocarbons cfcs to estimate the. For example, ozone and chlorofluorocarbons cfcs can be particularly useful in one environment, but can have damaging effects in another. Chlorofluorocarbon simple english wikipedia, the free. Chlorofluorocarbon article about chlorofluorocarbon by the.
Pdf chlorofluorocarbons cfcs and their effect on the. International journal of environment and pollution, environmental pollution, pollution, journal of environment pollution and human health, journal of geophysical research. Chlorofluorocarbons financial definition of chlorofluorocarbons. Since scientists linked cfcs to the depletion of the ozone layer, they have been largely phased out, but old refrigerators and other devices that use. Chlorofluorocarbons article about chlorofluorocarbons by. The regulations require a 50% reduction in consumption of fully halogenated chlorofluorocarbons cfcs within 10 years and a freeze on consumption of halons within 4 years. At room temperature the cfcs are gases or liquids with low boiling temperatures. Cfcs and their possible effects upon the global environment, in cluding the. Pdf the environmental impact of chlorofluorocarbon use in. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Their commercial and industrial value notwithstanding, cfcs were eventually discovered to pose a serious environmental threat. The chlorofluorocarbon and the halons are potent ozone depletors.
Australian chlorofluorocarbon management strategy pdf 331. The australian cfc management strategy acms has been developed to report on australias efforts to date in managing cfcs and to provide an ongoing framework for the responsible management and use of cfcs in australia. Health information summary chlorofluorocarbons cfcs are a group of colorless, non combustible liquids, also known as freons. Chlorofluorocarbons and the environment practice khan. The following states are members of the international atomic energy agency. Chlorofluorocarbons, also known as cfcs, consist of chemical compounds made up of chlorine, fluorine and carbon. They are also commonly known by the dupont brand name freon the most common representative is dichlorodifluoromethane r12 or freon12. Chlorofluorocarbons are more commonly referred to as cfcs or, when used for refrigeration, cfcs are also known as freon. Chlorofluorocarbons cfcs are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine. Since they are not wrecked in the lower atmosphere, cfcs float into the upper atmosphere where, given reasonable conditions, they destroy ozone layer. Replacement of hydro chlorofluorocarbons and chlorofluorocarbons by hydro. Due to an immediate lack of observable harmful results on the environment, they were considered a safe, nontoxic and nonflammable substitute for harmful chemicals such as ammonia, which was used for refrigeration and propellants in the early 1930s. What are the effects of chlorofluorocarbon on the environment. The irs works within the context of foreign treaties to determine how earnings from controlled foreign corporations are taxed in the.
1582 919 1180 649 980 479 1408 630 1175 388 490 1263 1314 1211 576 1110 983 1584 694 652 630 1135 564 654 82 1555 392 1013 1458 1400 1333 1360 1102 1114 1411 1385 1290 1079 983 1107 1051 1345 707 106