Concerned about sustainability and the harmful health effects of off-gassing chemicals in many residential floor coverings, longtime carpet makers Bill and Terry Green switched from using synthetic nylon fibers to natural wool in 1993. Not only is wool renewable, it's also nonallergenic, dirt-resistant, and flame-retardant. Even the backing material on the Calhoun, Georgia, company's Woolshire
carpets is green; it's made from a low-VOC soybean-based polyurethane. About $7 to $9 per square foot.