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, du ff, 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 ga s chromatography/flame ionization detection. The major condensible emi ssions were acetic acid, 2-furaldehyde, vinyl acetate, acetol, and met hanol. The oxygenated organic emissions have been shown to be dependen t primarily on fuel chemistry and secondarily on combustion efficiency . Molar ratios of individual compound emissions to CO emissions have b een calculated, and exposure levels to these compounds for wildland fi refighters have been estimated based on the ratios. Of the compounds m easured, none was projected to exceed a toxic level, except for 2-fura ldehyde and vinyl acetate, which are suspected carcinogens.