Polycyclic Aromatic Hydrocarbons and Select Inorganics in Smoke from Various WUI Fire Fuels: Vehicles, Trees, and Construction Materials

Published

September 25, 2025

Author(s)

Aika Davis, Ryan Falkenstein-Smith, Thomas Cleary

Abstract

Wildland-Urban Interface (WUI) fire smoke is complex since it contains anthropogenic and biogenic fuel sources, and emissions from WUI fire are not yet well characterized. We have conducted a comprehensive study to characterize polycyclic aromatic hydrocarbon (PAH) emission yields from select WUI fire fuels: internal combustion vehicles, trees, and construction materials in a stacked array to mimic a structure. The mixed fuel cribs (about 30 cm on each side, constructed in a cube) consisted of sticks of wood, gypsum board, oriented strand board (OSB), acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC), and polyurethane (PU). These WUI fire fuels were burned under oxygen consumption calorimeters to measure mass loss, heat release rate, and other combustion characteristic measurements throughout each test. The calorimeter's exhaust hood captured the fire plume, and smoke samples were continuously collected from the exhaust duct at a well-mixed location for the test duration. Sampling pumps pulled smoke samples from the duct through 47.0 mm quartz filters at 5.2 SLPM to 45 SLPM at nominally isokinetic sampling conditions. Particulate matter (PM) collected on filters was extracted with dichloromethane (DCM) and analyzed by gas chromatography-mass spectrometry (GC-MS) for PAHs. The PM samples were also analyzed on a combustion ion chromatography (CIC) for select halogens and phosphorus analyses. Total PAH yields (per combusted mass loss) are comparable among the three WUI fire fuels, with differences not being statistically significant. However, the composition of the particulates differed by fuel sources.

Citation

Technical Note (NIST TN) - 2354

Report Number

2354

NIST Pub Series

Technical Note (NIST TN)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.TN.2354

Local Download

Keywords

WUI fire, aerosol emissions, vehicle, tree, polycyclic aromatic hydrocarbon, gas chromatography, halogens

Citation

Davis, A. , Falkenstein-Smith, R. and Cleary, T. (2025), Polycyclic Aromatic Hydrocarbons and Select Inorganics in Smoke from Various WUI Fire Fuels: Vehicles, Trees, and Construction Materials, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.2354, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=960860 (Accessed October 13, 2025)