More than half of all couches tested in Duke University-led research contained potentially toxic or untested chemical flame retardants that may pose risks to human health, according to a study published yesterday in the journal Environmental Science & Technology.
The study analyzes 102 polyurethane foam samples from couches purchased for home use in the United States between 1985 and 2010. It found flame-retardant chemicals in 85 percent of couches tested and in 94 percent of those purchased after 2005, according to lead study author Heather Stapleton, associate professor of environmental chemistry at Duke’s Nicholas School of the Environment.
Tris, a chlorinated flame retardant that is considered a probable human carcinogen based on animal studies, was one of the chemicals detected. It showed up in 41 percent of the couch foam samples tested. Tris was phased out from use in baby pajamas in 1977 because of health risks.
Couch manufacturers treat foam padding with chemical flame retardants to meet requirements in California Technical Bulletin 117. TB 117 says all residential furniture sold in the state must be able to withstand a 12-second exposure to a small open flame without igniting. Intended to help reduce deaths and injuries from accidental home fires, the mandate has become the de facto national standard because of the economic importance of the California market.
According to the Alliance for Toxic-Free Fire Safety, New York and 11 other states are launching efforts in 2013 to restrict chlorinated Tris. Physicians for Social Responsibility-Los Angeles supports legislation in California to change TB 117 by implementing an alternative flammability standard that can be met without chemical retardants.
Stapleton and colleagues report that many manufacturers may not know what chemicals have been used in their couches. Most manufacturers buy their foam padding from a vendor, who buys the chemicals used to treat it from another vendor, they write. The identity of the chemical flame retardants often gets lost along the way, or is protected under law as proprietary.
In addition to Tris, the study found 17 percent of the foam samples contained the flame retardant pentaBDE, which is banned in 172 countries and 12 US states and was voluntarily phased out by US manufacturers in 2005.
PentaBDE is a long-lasting chemical that over time migrates into the environment and accumulates in living organisms. Studies show that this class of chemicals can disrupt endocrine activity and affect thyroid regulation and brain development. Early exposure to them has been linked to low birth weight, lowered IQ and impaired motor and behavioral development in children.