Smoke Component Yields from Bench-scale Fire Tests: 3. ISO 5660-1 / ASTM E 1354 with Enclosure and Variable Oxygen Concentration

By NIST and National Institute of Standards and Technology (NIST)

A standard procedure is needed for obtaining smoke toxic potency data for usein fire hazard and risk analyses. Room fire testing of finished products is impractical, directingattention to the use of apparatus that can obtain the needed data quickly and at affordablecost. This report presents examination of the fourth of a series bench-scale fire tests toproduce data on the yields of toxic products in both pre-flashover and post-flashover flamingfires. The apparatus is the ISO 5660-1 / ASTM E 1354 cone calorimeter, modified to have anenclosure and a gas delivery system allowing variable oxygen concentration. The test specimenswas cut from finished products that were also burned in room-scale tests: a sofa made ofupholstered cushions on a steel frame, particleboard bookcases with a laminated finish, andhousehold electric cable. Initially, the standard test procedure was followed. Subsequentvariation in the procedure included reducing the supplied oxygen volume fraction to 0.18, 0.16,and 0.14, reducing the incident heat flux to 25 kW/m2, and reducing the gas flow rate by half.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 thedetection limits were shown to be of limited toxicological importance relative to the detectedtoxicants. In general, performing the tests at the reduced oxygen volume fraction led to smallincreases on the toxic gas yields. The exceptions were an increase in the CO yield for thebookcase at 0.14 oxygen volume fraction. Reducing the incident heat flux had little effect onthe toxic gas yields, other than increasing variability. Reducing the gas flow rate reduced thelimits of detection by half, but also resulted in reduced gas yields at lower oxygen volumefractions. In none of the procedure variations did the CO yield approach the value of 0.2 foundin real-scale post flashover fire tests.

• Format: Paperback
• Language: English
• ISBN: 1496019539
• ISBN13: 9781496019530
• Release Date: February 2014
• Publisher: Createspace Independent Publishing Platform
• Length: 54 Pages
• Weight: 0.33 lbs.
• Dimensions: 0.1" x 8.5" x 11.0"