Toxicity of Burning Material
The deadly fires that spread through the MGM Grand Hotel and the Las Vegas Hilton during the past year have demonstrated the danger from toxic gases released from combustion on materials commonly found in homes and other buildings. The problem has special relevance for anyone contemplating building a new home or re-insulating an older one since there are substantial differences in the toxicity of insulating materials that one might choose to use.
Researchers at the University of Pittsburgh (March 7, 1981 issue of Science News) recently have tested the toxicity of some of these materials by burning them and exposing mice to the smoke produced. Such tests are tough on the unfortunate mice but the results may save human lives.
One of the least toxic materials used in houses is wood. Fiberglass insulation Is almost as good. Smoke from both materials is comparatively slow to kill. In the tests on mice, It took twenty to thirty minutes of exposure to fumes produced from burning measured amounts of wood and fiberglass in a test apparatus to kill half the mice.
By comparison, Teflon, used in some cooking utensils, and polyvinylchloride, used to coat electrical wiring and in some wallpaper, are particularly deadly. When burned, small amounts of these materials (less than 5% as much as the wood or fiberglass) killed half the mice in less than ten minutes.
Intermediate in toxicity when burned were the now commonly-used insulating materials such as polyurethane, wool and cellulose. Times taken to cause death in the tested mice ranged from ten to thirty minutes.
To prevent the rapid release of toxic gases from burning polyurethane and polystyrene (beadboard or Styrofoam) rigid insulation used in homes, building codes now require that they be covered on interior walls by sheetrock or other flame-resistant materials. When so installed, these materials are comparatively safe to use. Still, a person who remains in a burning house too long may never get out because of the released toxic gases.
