Laboratory Quantification of Emissions from Wildland-Urban Interface Fuels Using Fourier-Transform Infrared...

Area of Science:

• Environmental Science
• Combustion Science
• Toxicology

Background:

• Wildland-urban interface (WUI) fires pose significant risks.
• Understanding emissions from WUI fuels is critical for public health and fire management.
• Previous research often overlooks the impact of varying environmental conditions on fuel combustion.

Purpose of the Study:

• To quantify emissions from common WUI fuels under diverse oxygen and heat flux conditions.
• To identify the most hazardous WUI fuels and their primary toxic emissions.
• To improve wildfire emission models by incorporating environmental variables.

Main Methods:

• Quantified emissions from eight common WUI fuels using Fourier-transform infrared spectroscopy.
• Tested fuels under varying oxygen concentrations (0, 14, 21%) and heat fluxes (25, 50 kW/m²).
• Implemented a novel Toxicity Score method to rank fuel hazard.

Main Results:

• Emission factors for carbon monoxide (CO), carbon dioxide (CO₂), and other pollutants varied significantly with oxygen and heat flux.
• Polyvinyl chloride, asphalt shingles, and vinyl plank flooring were identified as the most hazardous fuels.
• Hydrogen chloride was the dominant toxicant; formaldehyde and CO were significant at lower heat fluxes and higher CO₂ at higher heat fluxes, respectively.

Conclusions:

• Fuel type and combustion conditions (oxygen, heat flux) critically influence WUI fire emissions and toxicity.
• Polyvinyl chloride, asphalt shingles, and vinyl flooring pose the greatest toxicological risk in WUI fires.
• Findings necessitate considering diverse environmental conditions in WUI fire research and emission modeling.