But a third type of the chemical, deca-BDE, is still widely used and can break down into the more toxic forms of PBDEs. Environmental activists and some scientists are pushing for a ban on deca-BDE, a persistent toxin that accumulates in the food chain.

"We're trying to head off the next PCB disaster in the Great Lakes," said Mike Shriberg, policy director for the Ann Arbor-based Ecology Center. "This chemical acts a lot like PCBs, is extremely persistent in the environment and bioaccumulates; once it's here it's very hard to get rid of it."
PCBs were a group of chemicals widely used as coolants in electrical transformers until they were banned in 1977. The chemicals, which can cause developmental problems in children and are suspected of causing cancer, are still found in some species of Great Lakes fish.