MEASUREMENT AND MODELING OF AIR TOXINS FROM SMOLDERING COMBUSTION OF BIOMASS

Oxygenated organic compounds in condensed (-45 degrees C) smoke of 29 bench-scale fires of ponderosa pine sapwood, needles, bark, litter, duff, and humus have been identified and quantified under three types of conditions (smoldering, self-sustained smoldering, and flaming). The analyses were performed by gas chromatography/mass spectrometry and gas chromatography/flame ionization detection. The major condensible emissions were acetic acid, 2-furaldehyde, vinyl acetate, acetol, and methanol. The oxygenated organic emissions have been shown to be dependent primarily on fuel chemistry and secondarily on combustion efficiency. Molar ratios of individual compound emissions to CO emissions have been calculated, and exposure levels to these compounds for wildland firefighters have been estimated based on the ratios. Of the compounds measured, none was projected to exceed a toxic level, except for 2-furaldehyde and vinyl acetate, which are suspected carcinogens.