Smoke Damage Potentials in Industrial Fire Applications

Abstract

A methodology is presented for the evaluation of smoke damage contours through the coupling of smoke damage functions, deposition profiles and damage thresholds. Previously developed smoke damage functions and deposition velocities are used to illustrate “far-field” smoke damage potentials both for materials representative of semiconductor fabrication facilities as well as large warehouse storage applications. For semiconductor fabrication, smoke damage associated with leakage current (LC) is important, while smoke staining is of primary interest in warehouse storage. Smoke deposition velocities, a key component to quantifying smoke deposition profiles, were determined in a small (1.0 m3) and large (1,200 m3) enclosure. Both enclosures resulted in comparable values. The velocities ranged from 1.2 to 7.3 × 10−4 m/s. To determine smoke damage potential contours for semiconductor fabrication facilities, electronic circuit board targets were used. Smoke damage was quantified by LC (i.e., shorting). The average normalized LC values for polyvinylchloride, polycarbonate, and nylon ranged from 0.72 to 6.1 × 10−4 A m2/g. For warehouse storage facilities, filter targets were used. Smoke damage was quantified by brightness change and odor (i.e., volatile organic compounds, VOC) measurements on the targets. Representative materials were liner board, polystyrene, and polymethyl methacrylate. The smoke damage threshold value for brightness change was 0.012 g/m2 and for odor was 0.025 g VOC/m2. Resulting contours showed strong radial dependency with distance from the fire/smoke source. Smoke damage reached ~28 m for semiconductor fabrication facilities, while for warehouse storage facilities, it was up to 100 m.