By Liz White, UT staffWashington-New research in the US has shown that the polyurethane foam insulation of refrigerator/freezers emits much less of its fluorocarbon blowing agent during disposal than previously assumed. The study found that, on average, only a quarter of the blowing agent in the rigid foam insulation is emitted during shredding. The appliance sector has previously assumed that all of the blowing agent in the foam was released into the atmosphere upon disposal of refrigerator/freezers. The research, by a team at the Appliance Research Consortium (ARC), was supported by the Environmental Protection Agency (EPA) and the Alliance for the Polyurethanes Industry (API). It is part of "an ongoing programme designed to determine the environmental fate of blowing agents in the disposal and shredding process in the US," said a statement from the US Association of Home Appliance Manufacturers (AHAM)-a founder of the ARC. The work assessed both direct emissions, as well as any "attenuation" or degradation of blowing agents in landfills. A refrigerator/freezer's energy efficiency is its most visible environmental impact, but "this new research is aimed at quantifying the environmental effect of these appliances at disposal," AHAM's statement saidFluorocarbon blowing agents are used in the US to make the insulating foam encased in the walls of refrigerator/freezers. "Appliance manufacturers have been leaders in deploying ozone-friendly refrigerants and foam blowing agents while increasing the energy efficiency of their products," said Jeff Cohen, chief of the EPA's Alternatives and Emission Reduction Branch. "This study is part of a continuing partnership to not only address emissions of ozone depleting chemicals from older equipment, but to also minimize atmospheric emissions of the alternatives through responsible use and innovative technologies."Other conclusions of the study were:* Virtually no blowing agent is released during the life of the refrigerator because the foam is encapsulated inside the appliance walls and diffusion of fluorocarbons in the rigid foam is very slow.* If attenuation is occurring in landfills, it is possible that a significant amount of the blowing agent, in particular CFC blowing agents, may be degraded within the waste layers of a landfill. The agent is thus never released to the atmosphere, which further diminishes the ozone-depleting effect of the foam.AHAM says further work is necessary "to determine the breakdown products of shredded foam in landfills and the capacity of landfills to absorb these chemicals." For the present study, research contractors W.Z. Baumgartner & Associates determined the representative size of shredded foam from various US scrap yards, and the Technical University of Denmark conducted the chemical analyses for this project.This research will be presented at API's Polyurethanes 2005 Technical Conference & Trade Fair, October 17-19, 2005, in Houston, Texas. A full summary of the conclusions and details of the research can be obtained in the Publications section of http://www.aham.org/. For information on stratospheric ozone protection, visit http://www.epa.gov/ozone. More information on the API Polyurethanes 2005 Technical Conference & Trade Fair can be found at http://www.polyurethane.org/."