A PRELIMINARY COMPARISON OF LABORATORY METHODS FOR ASSIGNING A RELATIVE TOXICITY RANKING TO AIRCRAFT INTERIOR MATERIALS

Abstract : Thirteen aircraft interior materials have been tested in order to compare the National Bureau of Standards (NBS) smoke chamber and the microcombustion tube furnace as methods for generating toxic combustion gases. The microcombustion tube furnance ranked nitrogen- and chloride-containing test materials of known composition according to the expected order based upon HCN and HCl concentrations. The nitrogen-containing test materials were not ranked in the expected order by measuring peak gas concentrations in the NBS smoke chamber. Several methods of sampling combustion gases from the NBS smoke chamber have been investigated in an attempt to maximize sample recovery. These methods include colorimetric detector tubes, bag sampling, impinger sampling, and syringe sampling. In general, syringe sampling resulted in the best sample recoveries of the methods tested in this study. Animal toxicity tests were conducted for nine aircraft interior materials using Sprague-Dawley rats. A relative toxicity ranking of these predominantly nitrogen-containing materials has been determined by exposing the test animals to the combustion products obtained by decomposing the materials in a combustion tube furnace. A preliminary correlation of animal toxicity data with measured gas concentrations indicates that a possible relationship exists between times-to-incapacitation and hydrogen cyanide concentrations produced by the test materials. The coefficient of correlation is 0.93.