Foam Insulation Problem by Alex Wilson and the CFC The concern over ozone depletion in the upper atmosphere, and efforts to curtail the use of CFCs (chlorofluorocarbons), is likely to have far-reaching effects on the way houses are built. A recent conference in Washington, D.C., "Substitutes and Alternatives to CFCs and Halons," held January 13-15, brought over 600 people together from widely divergent backgrounds to discuss this issue. CFCs, known most commonly by their DuPont tradename, "Freon," have been used since the 1920s as refrigerants, aerosol propellants, industrial solvents, sterilization fluids, and foam-blowing agents for both rigid and flexible foams. Halons are a more recent class of chemicals which are used in fire extinguishing. United States End-Uses of CFCs Source* United States EPA, December 1987 Both CFCs and halons