UNITED STATES - The National Toxicology Program (NTP) review panel has concluded the carcinogenic activity of pentabromodiphenyl ether (penta-BDE) flame retardants, approving a technical report on the matter.
Commonly used in upholstery foam, penta-BDEs have been largely withdrawn since 2004 due to concerns about their environmental effects. The U.S. Centers for Disease Control and Prevention has found that they are bioaccumulative pollutants that are retained by most people in their body tissues.
The technical report has considered a technical grade of penta-BDEs, known as DE-71, which has a mixture of penta-BDE isomers. Toxicology studies were conducted in rats and mice for 3 months. Toxicology and carcinogenicity studies were also conducted in rats for 2 years. The studies have been composed of animals that were fed with the compounds during pregnancy and through birth to adulthood. Based on these studies, it has been concluded that the mixture was a carcinogen in both species, causing liver tumors and potentially precancerous lesions in the liver and thyroid.