We don't think of our furniture as a health hazard, save for maybe the sharp corners of a kitchen table. But several studies have shown that the materials used to make furniture -- from the formaldehyde used in wood adhesives, to the chemicals used in upholstery -- can cause long-term health issues, including respiratory problems, developmental delays, and fertility issues. The latest such study, by researchers at Duke University and the University of California at Berkeley, found many sofas contain a toxic flame retardant linked to cancer, hormone disruption and neurological problems. Overall, 85 percent of the 102 polyurethane-foam sofas tested were treated with flame retardants known to be toxic or that lack information about their health effects. Forty-one percent contained cancer-causing chlorinated Tris (TDCPP), a flame retardant banned for use in children's clothing in 1977. Seventeen percent contained the chemical pentaBDE, which has been banned worldwide since 2004. Researchers even found toxic flame retardants in sofas labeled as eco-friendly.read more