Characterization of volatile organic compounds in smoke at experimental fires

Significant associations between firefighting and cancer have been reported; however, studies finding toxic products of combustion at municipal fires have been limited by (1) technical difficulties encountered at the scene of working fires, (2) the lack of a coherent sampling strategy, and (3) the absence of verified sampling methods. The objective of the present study was to characterize the presence of volatile organic compound (VOC) combustion products in fire smoke. Air samples from experimental fires burning various materials commonly found at structural fires were collected into evacuated Summa canisters and analyzed for 144 target VOCs using cryogenic preconcentration and gas chromatography/mass spectroscopy (GC/MSD) methodology. The resulting chromatograms were characterized by a small number of predominant peaks, with 14 substances (propene, benzene, xylenes, 1-butene/2-methylpropene, toluene, propane, 1,2-butadiene, 2-methylbutane, ethylbenzene, naphthalene, styrene, cyclopentene, 1-methylcyclopentene, isopropylbenzene) being found in proportionately higher concentrations in all experimental fires and accounting for 65% (SD = +/-12%) by mass of total measured VOCs. Benzene, toluene, 1,3-butadiene, naphthalene, and styrene were found at higher concentrations than most other VOCs and increased with the time of combustion together with increasing levels of carbon monoxide. Benzene was found in the highest concentrations, with peak levels ranging from 0.6 ppm to 65 ppm, while the levels of 1,3-butadiene, styrene, and naphthalene peaked at 0.1, 0.4, and 3 ppm, respectively. This study revealed that there were no new or novel, toxic nonpolar VOCs resulting from the burning of common building materials. This is important in view of the studies that have found associations between firefighting and various forms of cancer.