In the first publicly available study of its kind, a type of foam carpet pad commonly sold in the USA and other developed countries was demonstrated to contain levels of flame retardant chemicals that raise concerns about human health. The substances, PentaBDE and OctaBDE, resemble PCBs in structure and toxic effects.
The study, conducted by IPEN, an international organization working on toxic chemical 
issues, examined levels of polybrominated diphenyl ethers (PBDE) in foam carpet pads commonly used in developed counties, including the United States.
IPEN Brominated Flame Retardants in Carpet Foam press release 25 April 2011