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Research: Overhaul’s dangers examined

There is a growing body of evidence showing that contaminated air after the fire poses a serious health risk

Questions often arise as to the correct level of protection that should be applied during overhaul and other post-fire operations. A particularly common inquiry is the appropriate level of respiratory protection and how long the SCBA should be worn following a fire.

Certainly, practices have evolved over the past several years, where firefighters are more aware of hazards of exposure to contaminants both on the fireground and those that accumulate in clothing. Many departments have implemented operating procedures that requirement wearing PPE.

Nevertheless, we hear that many firefighters may be ignoring these procedures or simply making protection decisions based on incomplete information. We recently attended an Interagency Board (IAB) workshop where these issues were brought to the forefront.

The IAB is a panel of emergency preparedness and response practitioners from a wide array of professional disciplines representing the public safety sector at all levels of government.

Based on direct field experience, IAB members advocate for and assist the development and implementation of performance criteria, standards, test protocols, technical and operating guidance, and training requirements for all-hazards incident response with an additional special emphasis on Chemical, Biological, Radiological, Nuclear, and Explosive issues.

The IAB’s Equipment Sub Group focuses on identifying appropriate response equipment and promoting the development of associated standards and operational considerations. The IAB recommendations are published as the Standardized Equipment List found at both and

Multi-gas detectors
The IAB equipment subgroup recently prepared a position paper entitled, “Evaluation of Hazards in the Post-Fire Environment.” This paper was in response to questions regarding the use of multi-gas detectors to make decisions for selecting personal protective equipment to protect firefighters and other personnel from airborne hazards in the post-fire environment.

A number of fire departments have increasingly based their decisions for the continued wearing of SCBA using measurements of carbon monoxide, and sometimes other gases such as hydrogen cyanide and sulfur dioxide. However, using multi-gas detectors to evaluate a complex atmosphere that contains high levels of gases, vapors and particulates is questionable.

Moreover, the reliance on contaminant levels for a few target questions does not account for the wide range of hazardous chemicals that may be present on scene, which have both short and long-term health consequences.

For example, such detectors cannot detect the presence of polycyclic aromatic hydrocarbons (PAHs) that adsorb onto smoke particulates that represent a significant health risk. These risks are also persistent from secondary exposure to contaminated garments and equipment.

Based on the review, the IAB has recommended the following:

  • Organizations should not solely rely on multi-gas detectors to determine PPE donning and doffing action levels.
  • Organizations should alter the procedures to conduct field expedient decontamination procedures as soon as reasonably feasible after post-fire operations, and laundering and decontamination of garments must, at a minimum, be conducted in accordance with NFPA and manufacturer recommendations.

  • Further research should be conducted to identify and quantify the full spectrum of post-fire environment hazards as well as appropriate protection and decontamination technologies.

The IAB paper further recommends giving priority to research in five areas to establish a better understanding of post-fire environment hazards: determining the efficacy of respiratory protective equipment; learning how structural firefighting protective equipment and possible enhancements to the equipment can reduce skin absorption risks; developing strategies and selection guidelines to mitigate risk; determining the effectiveness of decontamination approaches; and identifying better detection technology that can be applied to the post-fire environment.

New findings
Speakers at the IAB workshop detailed specific hazards and findings from studies and investigations of firefighter exposure to different airborne contaminants in the post-fire environment. These presentations collectively showed a variety of different hazardous chemicals persisting on the fire ground during and following overhaul.

Some study information related to specific reviews of cancer incidence for firefighters against the general population. For example, the National Institute for Occupational Safety and Health is in the third year of an extensive research project to determine the incidence of specific cancers for firefighters in three large metropolitan fire departments over multiple decades. Those findings will not be available for at least another year.

The workshop also included a panel of fire-service representatives who discussed their specific experiences and perspectives related to the need for firefighter respiratory protection and decontamination relative to the post fire-environment.

While many of these firefighters admitted to significant improvements in firefighter health and safety awareness, there were general concerns for the under appreciation of hazards facing firefighters during the overhaul as well as the continued dermal exposures the firefighters have in wearing contaminated clothing and equipment.

All panel members believed that these topics required further investigation, but more importantly action on the part of the fire service to be more aggressive in following safe practices that minimize unnecessary chemical exposures.

As in indicated in the title of one presentation — “No smoke, no fire, no problem” — the assumption that the protective ensemble is not fully needed in the post-fire environment is dangerous. And, continuing to use contaminated clothing and equipment further elevates the risk. But measures can be taken to lower that risk and hopefully reduce the potential for both acute and chronic health issues from unnecessary exposures.

Get all the facts about Personal Protective Equipment. Foremost PPE expert Jeffrey Stull writes ‘PPE Update,’ a FireRescue1 column that covers personal protective equipment options, fit, selection and all the regulations for its care and maintenance.