AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Fine Particle Exposures During Vehicle Fire Suppression: Mobile Direct Reading Sampling
DOUGLAS EVANS, Kenneth Fent, James Couch, NIOSH DART
Abstract Number: 335 Working Group: Aerosol Exposure
Abstract Objective: According to both the US Fire Administration and the National Fire Protection Association, fire departments responded to in excess of 300,000 vehicle fires per year on average, more frequent than residential fires and making up approximately one quarter of all responses. Despite the common nature of vehicle fires, relatively few studies characterizing the emissions or potential for firefighter exposures have been conducted.
Methods: Six vehicle fires were initiated (three engine and three cabin), with subsequent fire suppression conducted by a local fire crew during fire training exercises. Through flexible metallic duct, air samples were drawn from the location of fire crew (nozzle operator) to a mobile aerosol instrument sampling platform, for simultaneous measurements of particle number, respirable particle mass, active surface area, photoelectric response, particle size distribution and air quality parameters. Chemical vapors were also monitored, but these results have been presented elsewhere.
Results: Fire crews were potentially exposed to combustion products as the smoke plume backed and veered. These instances occurred during both knockdown and overhaul phases of the response. Fifteen minute average particle concentrations of 324,000 particles/cm3 and 5.9 mg/m3 respirable mass were attained, although transient peak concentrations were substantially greater.
Conclusions: Potential for firefighter exposure to particles was primarily determined by the direction of the wind during fire suppression and included both the knockdown and overhaul phases of the fire response. To reduce the risk from exposure to airborne contaminants, firefighters should don self contained breathing apparatus (SCBA) on arrival at the fire scene and doff SCBA only after overhaul is complete.