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cburr Teacher
Middle SchooleNotes Editor
Posted by cburr on Sunday February 8, 2009 at 10:00 AMThe full name for CFCs is chloroflourocarbons, which just means that these synthetic compounds include chlorine (chloro), flourine (flouro) and carbon.
CFCs are used
- to produce cold air in refrigerators and air conditioners,
- to make plastic foams for furniture, insulation, etc.
- for aerosol in spray cans.
The problem is that when CFCs are released into the air they can get to the stratosphere (one of the layers of atmosphere around the earth) and destroy ozone gas. This can create a "hole" in the ozone layer around the earth and allow in more ultraviolet radiation from the sun.
A really good site to learn about this is in "How Stuff Works." Here's a quote that explains how CFCs deplete ozone:
CFCs, which are man-made, gradually rise up into the ozone layer, where ultraviolet light breaks the compounds apart, which releases chlorine. A chlorine atom can steal an oxygen atom from an ozone molecule, creating oxygen gas and chlorine monoxide (ClO), which effectively destroys the ozone molecule. But the chlorine atom isn't done yet; a chlorine atom can break from its oxygen atom and wreak havoc on as many as 10,000 more ozone molecules. . . After years of unrestrained CFC production, the ozone would deplete significantly. [sources removed from quote]
Here's the link to that article -- there are other related articles that are useful, too.
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ronald75 Student
College - JuniorPosted by ronald75 on Thursday April 9, 2009 at 4:11 AM<!-- /* Font Definitions */ @font-face {font-family:Helvetica; panose-1:2 11 6 4 2 2 2 2 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:536902279 -2147483648 8 0 511 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} -->
Chlorocarbons, CFCl3 (CFC-11) and CF2Cl2 (CFC-12) because of their larger concentrations and potentially significant effects on stratospheric ozone. CFC-11 and CFC-12 have the highest concentrations of the man-made chlorocarbons, around 0.27 and 0.55 ppbv, respectively (measured at Mauna Loa in 1997, Fig. 5 & 6). As indicated in their GWP values, these two gases are strong infrared absorbers. It is thought that CFC-11 and CFC-12 have contributed about one-third of the radiative forcing of gases other than CO2 during the 1980s.
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charles85 Student
Community / Jr. CollegePosted by charles85 on Thursday April 9, 2009 at 4:18 AM<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} -->
Since the appearance of an ozone hole (because of large quantity of CFCs) over the Antarctic in the early 1980s, Americans have become aware of the health threats posed by ozone depletion, which decreases our atmosphere's natural protection from the sun's harmful ultra-violet (UV) rays. One of the disease is skin cancer affected by depleting ozone layer due to CFCs.
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