Combustion products generated in simulated industrial fires.

Studies of firefighter exposure to combustion products have focused predominantly on real or simulated residential structure fires, with few investigations considering industrial fire scenarios. This study measured the atmospheric concentrations of a variety of volatile organic compounds (VOCs), acid gases, and polycyclic aromatic hydrocarbons (PAHs) produced during fires in simulated industrial premises, as well as the deposition of PAHs onto the structural firefighting ensembles worn by the firefighters involved in extinguishment activities. Ingress of these combustion products into the structural firefighting ensembles during firefighting was also measured. Benzene concentrations of up to 23 mg/m3 and total PAH concentrations ranging from 1.7 to 8.6 mg/m3 were observed in personal air samples collected outside the structural firefighting ensembles, as well as a variety of acid gases including hydrogen chloride and hydrogen cyanide. Most combustion products detected outside the structural firefighting ensembles were also detected inside the ensembles, although often at much lower concentrations. The degree of protection observed was not uniform across all the combustion products investigated, with lower levels of protection found for gaseous combustion products such as benzene, xylene, hydrogen cyanide, and hydrochloric acid as compared with PAHs. Deposition of a variety of PAH compounds was observed on the outer surface of the structural firefighting ensembles, with total PAH concentrations ranging from 161 to 347 ng/cm2. While similar combustion products are involved in firefighter exposures during residential and industrial fires, deposition rates of PAHs, may be substantially higher during industrial firefighting. This research provides evidence supporting fireground decontamination measures for management of contamination of structural firefighting ensembles and equipment worn or carried by firefighters during firefighting activities. Further research is required to investigate the potential for dermal deposition of PAHs during actual industrial fire responses, and characterize which stages of fire and firefighting operations contribute the most to firefighters' exposure to particular contaminants.

Exposures to air contaminants in compartment fire behavior training (CFBT) using particleboard fuel.

Firefighters are exposed to a variety of combustion products during operational fires but also during live-fire training. As part of an on-going project investigating firefighter operational and training environments, this study measured the atmospheric concentrations of volatile organic compounds and acid gases outside and inside the structural firefighting ensembles worn by instructors during compartment fire behavior training using particleboard as a fuel. Atmospheric concentrations of benzene, formaldehyde, and hydrogen cyanide within the firefighting environment were observed to exceed Australian workplace exposure standards; although, the use of self-contained breathing apparatus throughout the training meant that atmospheric concentrations measured were not representative of firefighter inhalation exposures. Concentrations of air contaminants inside the structural firefighting ensembles during compartment fire behavior training were substantially lower than outside the ensembles, and much lower than those documented as potentially causing acute toxic effects in humans by dermal absorption from vapor. Although this study is focused on the generation of air contaminants in compartment fires, dermal absorption in these types of training environments may still constitute a potential route of low-level exposure to some combustion products.

Diesel particulate matter and polycyclic aromatic hydrocarbons in fire stations.

Firefighters are known to be exposed to a wide variety of combustion products during operational and training firefighting activities. However, the potential for exposure to diesel exhaust emissions, recently classified as carcinogenic to humans by the International Agency for Research on Cancer, also exists within the fire station environment. In this study, concentrations of diesel particulate matter and polycyclic aromatic hydrocarbons have been measured in the engine bays, duty offices and dormitory areas of eight fire stations in Queensland, Australia. Operation of fire appliances and mechanical equipment during start of shift checks were found to contribute more strongly to overall engine bay diesel particulate matter concentrations than the number of fire appliance departures and returns. Polycyclic aromatic hydrocarbons were found to be transported further into fire station living environments than diesel particulate matter. This study highlights a number of potential strategies for reducing firefighter exposures to components of diesel engine exhaust in the fire station environment.

Firefighting instructors' exposures to polycyclic aromatic hydrocarbons during live fire training scenarios.

Cumulative exposures of firefighting instructors to toxic contaminants generated from live-fire training potentially far exceed firefighter exposures arising from operational fires. This study measured the atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) outside and inside the structural firefighting ensembles worn by instructors during five live fire training evolutions. In addition, the contamination of ensembles by deposition of PAHs was characterized. Concentrations of polycyclic aromatic hydrocarbons outside the instructors' structural firefighting ensembles during the training evolutions ranged from 430 µg/m(3) to 2700 µg/m(3), and inside the structural firefighting ensembles from 32 µg/m(3) to 355 µg/m(3). Naphthalene, phenanthrene and acenaphthylene dominated the PAHs generated in the live fire evolutions, but benzo[a]pyrene was the greatest contributor to the toxicity of the PAH mixture both inside and outside the structural firefighting ensembles. Deposition of PAHs onto the structural firefighting ensembles was measured at between 69 and 290 ng/cm(2), with phenanthrene, fluoranthene, pyrene, and benzo[a]anthracene detected on all samples. These findings suggest that firefighting instructor exposures to PAHs during a single live-fire training evolution are comparable with exposures occurring in industrial settings over a full shift. Further research is required to investigate the importance of various potential routes of exposure to PAHs as a result of ingress and deposition of PAHs in/on structural firefighting ensembles.

Structural Fire Fighting Ensembles: Accumulation and Off-gassing of Combustion Products.

Firefighters may be exposed to toxic combustion products not only during fire fighting operations and training, but also afterwards as a result of contact with contaminated structural fire fighting ensembles. This study characterized the deposition of polycyclic aromatic hydrocarbons (PAHs) onto structural fire fighting ensembles and off-gassing of combustion products from ensembles after multiple exposures to hostile structural attack fire environments. A variety of PAHs were deposited onto the outer layer of structural fire fighting ensembles, with no variation in deposition flux between new ensembles and already contaminated ensembles. Contaminants released from ensembles after use included volatile organic compounds, carbonyl compounds, low molecular weight PAHs, and hydrogen cyanide. Air samples collected in a similar manner after laundering of ensembles according to manufacturer specifications indicated that laundering returns off-gassing concentrations of most of the investigated compounds to pre-exposure levels. These findings suggest that contamination of firefighter protective clothing increases with use, and that storage of unlaundered structural fire fighting ensembles in small, unventilated spaces immediately after use may create a source of future exposure to toxic combustion products for fire fighting personnel.