Wildland-Urban Interface (WUI) Smoke Yields of Nonmethane Organic Gases from Combustion of Small-Scale Residential Building Surrogates

At the wildland-urban interface (WUI) structural fires can generate nonmethane organic gases (NMOGs) from burning urban fuels like structural lumber, plastics, and carpet. These NMOGs can contaminate nearby homes and affect indoor air quality. NMOGs have been quantified extensively from biomass burning, but few measurements exist of yields from structure fires. We calculated yields of 201 NMOGs generated from burning small-scale residential building surrogates. We also constructed surrogates of different sizes and stick packing densities to modulate air ventilation and simulate how reduced oxygen conditions in enclosed fires might affect NMOG yields. We find that reduced aromatics (e.g., benzene, naphthalene) show notably higher yields from combustion of the surrogates compared to biomass, whereas oxygenated NMOG (e.g., formaldehyde, acetaldehyde) yields are lower. Using factor analysis of NMOG time series, we observe chemical signatures from the combustion of synthetic polymers, wood, and mixed fuel char. Though we do not identify unique tracers we identify NMOGs that, if present in enhanced concentrations, may indicate WUI fire contamination in homes.