Chemical Composition of Overhaul Smoke After Use of Three Extinguishing Agents

The effect of extinguishing agents on the composition of smoke from wood fires of different intensities was studied. Three agents were examined: water, a protein-based water additive, and a sulfonate detergent-based compressed air foam (CAF). Air samples were analyzed for volatile organic compounds (USEPA 502 list), aldehydes, polyaromatic hydrocarbons, acid gasses, CO, CO₂, SO _x , and total volatile hydrocarbons. Air concentrations of levoglucosan and methoxyphenols, which are specific products from burning cellulose and lignin, respectively, were also measured. Levoglucosan, methoxyphenols, and many of the polyaromatic compounds have not been previously reported in overhaul smoke. A solitary test with water extinguishment was repeated for an assessment of variability. HCN and acid gases were not present in significant concentrations. The principal components that contributed appreciably to short-term occupational exposure hazards were formaldehyde, acrolein, benzene, polyaromatic hydrocarbons, and carbon monoxide. When a flocculation effect that cleared air particulate occurred during the use of the protein-based water additive, air concentrations of most chemicals in the air samples were reduced.