Plastics readily burn. That's why their makers add fire-suppressing chemicals. But some of these additives have been shown to be harmful to animals and are being phased out. In an upcoming Nature Materials, researchers describe another way to smother plastic's fiery potential: Include a network of carbon nanotubes.
Brominated fire retardants, which are in everything from computers to furniture, have proved effective, but they accumulate throughout the environment, showing up even in breast milk. Two subclasses of the chemicals have already been banned by the European Union, and, beginning in 2008, they will be illegal in the state of California.
During a fire, plastic melts as the polymer chains within it break down. As the burning progresses, some of the polymer vaporizes, forming gas bubbles that feed and intensify the flames, says Takashi Kashiwagi, a materials engineer at the National Institute of Standards and Technology (NIST) in Gaithersburg, Md. One way