substantial amounts of ozone-depleting chlorofluorocarbons into the earth’s atmosphere.
Shredded foam insulation from discarded refrigerators is releasing substantial amounts of ozone-depleting chlorofluorocarbons, or CFCs, into the earth’s atmosphere — and the more finely shredded the foam, the faster the release, a Danish researcher reports.
The first study looking at how and how fast CFC gas releases from foam insulation used in older refrigerators is reported in the July 15 issue of Environmental Science & Technology.
More than eight million refrigerators and freezers in the United States reach the end of their useful lives and are thrown away annually, generally ending up at a landfill where they are shredded to recover scrap metal.
Shredding one discarded refrigerator can quickly release more than 100 grams of CFC-11 into the environment, reports Peter Kjeldsen, Ph.D., an associate professor at the Technical University of Denmark.
All 500 grams of CFC gas in the insulation of each refrigerator — a total of nearly 4,000 tons of CFC emissions — can eventually seep from the appliances over the next 300 years, he said.
A single chlorine atom — contained in CFCs and also found naturally — can destroy more than 100,000 ozone molecules Comparing their laboratory CFC-release rates to computer models, the researchers found that all CFC gas embedded in the energy-saving insulation is released slowly after the foam is ripped apart.
Although CFCs were developed in the 1930s, the majority of the CFC emissions are coming from refrigerators made during the 1980s, when a new type of insulating foam featuring the material was used. The appliances normally last for around 20 years, Kjeldsen said.
‘Use of these results may help evaluate changes in the atmospheric concentrations of CFC-11 in the future,’ said Kjeldsen. ‘They add to the understanding of a very important source of CFCs.’