Airborne contaminants during controlled residential fires

Area of Science:

• Environmental Health & Safety
• Occupational Health
• Fire Science

Background:

• Residential fires produce complex mixtures of combustion byproducts.
• Modern furnishings contribute unique chemical profiles to fire emissions.
• Firefighter exposure to these toxins is a significant occupational hazard.

Purpose of the Study:

• To quantify airborne concentrations of combustion byproducts during controlled residential fires.
• To assess firefighter exposure levels across various job roles and fire attack tactics.
• To compare exposures between interior and transitional fire attack methods.

Main Methods:

• Controlled residential fires with common 21st-century furnishings were conducted.
• Area and personal air samples were collected for polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and hydrogen cyanide (HCN).
• Measurements were taken during active fire, overhaul, and on the fireground, with different fire attack tactics employed.

Main Results:

• Median personal air concentrations for attack and search firefighters exceeded occupational exposure limits for several compounds.
• Hydrogen cyanide (HCN) levels for outside ventilation firefighters surpassed exposure limits and Immediately Dangerous to Life and Health (IDLH) levels.
• Airborne concentrations decreased post-suppression, but some overhaul firefighters still exceeded limits for PAHs and benzene.
• No significant exposure differences were found between interior and transitional fire attack tactics.

Conclusions:

• Firefighters experience high exposures to combustion byproducts, necessitating consistent use of self-contained breathing apparatus (SCBA).
• Overhaul and outside ventilation activities pose particular risks.
• Strategic positioning of command posts upwind of fires is recommended to minimize exposure.