Sudden water exposure on geared firefighters may cause unexpected burns in post-fire periods

Abstract

The wetting of fire protective clothing (FPC) is a possibility during fire suppression activities. Hose spraying, inadequate hose usage, accidental water splashes, etc., can be significant water sources which may drastically alter the thermal performance of the FPC. The effect of wetting the FPC outer shell during an exposure scenario on its thermal performance is studied in this numerical study. The exposure scenario considered consists of heat exposure and post-exposure phases, assuming the wetting only happens in the post-fire. Results are discussed relative to when the wetting occurs (i.e., pre-wetting, wetting, and post-wetting phases), identifying the main heat and mass transfer mechanisms responsible for the registered thermal hazards. Second-degree burn times, as well as other thermal performance indicators, are obtained for different wetting times, heat exposure intensities, and outer shell wetting levels. Wetting of the outer shell of an FPC during an exposure scenario can have a highly non-linear effect on second-degree burn occurrence, making it a very challenging phenomenon to consider in the design of FPCs. Firefighters should be warned that any water sprinkling after a fire exposure may cause burns at the most unexpected times during a typical firefighting scenario.