Nist

Smoke Component Yields from Bench-scale Fire Tests: 4. Comparison of Bench-scale Nist

A standard procedure is needed for obtaining smoke toxic potency data for use in fire hazard and risk analyses. Room fire testing of finished products is impractical, directing attention to the use of apparatus that can obtain the needed data quickly and at affordable cost. In this work we compare yields of toxic gases generated by four bench scale apparatus to previously conducted room-scale fires. The bench scale apparatus are the radiant apparatus in NFPA 269 and ASTM E 1678, the smoke density chamber in ISO 5659-2, a controlled-atmosphere version of the cone calorimeter (ASTM E 1354),and the tube furnace in ISO/TS 19700. In the bench scale experiments, the test specimens were cut from finished products that were also burned in the room-scale tests: a sofa made of upholstered cushions on a steel frame, particleboard bookcases with a laminated finish, and household electric cable. The yields of CO2 CO, HCl, and HCN were determined. The yields of other toxicants (NO, NO2, formaldehyde, and acrolein) were below the detection limits, but volume fractions at the detection limits were shown to be of limited toxicological importance relative to the detected toxicants. The bench scale and room scale yields are compared, and the bench scale apparatus are assessed for the degree to which they accurately predict room scale yields. The results of this study provide a better basis for obtaining toxic potency input data for fire modeling than currently exists.