Volatile Organic Compounds Profile from Laboratory Scale Combustion Emissions of Regionally Relevant Wood Types and Synthetic Building Materials

YIN YEE (CYNTHIA) CHOO, David Kalafut, Marilyn Black, William Goldsmith, Thomas Batchelor, Anand Ranpara, Timothy Nurkiewicz, Mark Wilson, UL Research Institutes

     Abstract Number: 288
     Working Group: Burning Questions of Aerosol Emissions, Chemistry, and Impacts from Wildland-Urban Interface (WUI) Fires

Abstract
Wildland-urban interface (WUI) fires are uniquely complex due to the combustion of both natural biomass and synthetic materials, resulting in emissions with chemical profiles distinct from those of wildfires or structural fires alone. Despite the growing threat, there are still significant knowledge gaps regarding the chemical composition of WUI fire emissions. Although field collection and analysis of emissions from WUI fires is feasible, the unpredictable nature of wildfire events both in timing and location poses significant challenges to obtaining consistent and representative samples. Our research group developed a novel laboratory-scale combustion system to simulate WUI fire conditions under controlled parameters to overcome these challenges. Pellets were fabricated from four regionally representative wood species- red oak, ponderosa pine, loblolly pine, and douglas fir to model wildland biomass. Additional composite pellets were produced by combining each wood type with synthetic building materials commonly present in modern homes, including polystyrene insulation, oriented strand board (OSB), and vinyl flooring. These fuels were combusted in a modified pellet furnace with a programmable feed rate and integrated air sampling ports. A total of 20 different pellets were combusted in the first phase of this project. Emissions were captured on 2,4-dinitrophenylhydrazine (DNPH) cartridges and Tenax TA® sorbent tubes for quantitative analysis of carbonyl compounds and volatile organic compounds (VOCs), respectively. Preliminary results indicate that methyl vinyl ketone, formaldehyde, and acetaldehyde are consistently among the highest-emitting VOCs across all biomass-only combustion scenarios. The inclusion of synthetic materials led to a marked increase in emissions of styrene, a compound absents in pure wood combustion. Our approach allows for controlled generation and chemical characterization of this complex mixture which is useful for exposure modeling and incorporation into in-vivo and in-vitro toxicity assessments.