Characterization of firefighter exposures during fire overhaul

Area of Science:

• Occupational Health and Safety
• Environmental Science
• Firefighter Research

Background:

• Limited data exists on firefighter exposures during the overhaul phase of structure fires.
• Firefighters often work without respiratory protection during overhaul, searching for hidden fires.
• Previous studies focused on fire suppression, not the post-fire inspection phase.

Purpose of the Study:

• To comprehensively characterize firefighter exposures to various airborne contaminants during the overhaul phase.
• To assess compliance with established occupational exposure limits during overhaul operations.
• To determine the efficacy of carbon monoxide as an indicator for other combustion products.

Main Methods:

• Conducted air monitoring during the overhaul phase of 25 structure fires in Phoenix.
• Collected personal and area samples for a range of chemicals including aldehydes, benzene, polynuclear aromatic hydrocarbons (PNA), and metals.
• Utilized gas analyzers for continuous monitoring of carbon monoxide (CO), hydrogen cyanide (HCN), nitrogen dioxide (NO2), and sulfur dioxide (SO2).

Main Results:

• Exceedances of ceiling values for acrolein, CO, formaldehyde, and glutaraldehyde were observed.
• Short-term exposure limits were exceeded for benzene, NO2, and SO2.
• Polynuclear aromatic hydrocarbon (PNA) concentrations exceeded recommended exposure limits on an additive effects basis.

Conclusions:

• Firefighter exposures to multiple hazardous substances during overhaul frequently exceed established limits.
• Respiratory protection is strongly recommended for firefighters during the overhaul phase.
• Carbon monoxide (CO) levels are not reliable indicators of other hazardous combustion products present during overhaul.