“Fire scenes, by their nature, are dangerous places.” So says the National Fire Protection Association (NFPA) in the first sentence of Chapter 13 of its NFPA 921, “Guide for Fire and Explosion Investigations.”
The presence of hazards at fire scenes is well documented in the firefighting community. The need to recognize hazards, assess their potential impacts on human health and the environment, and, when appropriate, mitigate and control them via personnel protective equipment and administrative or engineering controls is apparent.
Some of the hazards may be quite obvious, such as holes in floors, dangling electric conductors, sharp exposed edges, and slippery surfaces. Other hazards may be less obvious, like chemical exposures and obscured physical hazards.
Another potential hazard is asbestos. Asbestos is a naturally occurring mineral and has long been used in construction. It has excellent heat insulating and fire-resistance properties.
When people are exposed to asbestos fibers without respiratory protection, a condition known as asbestosis can develop. Asbestosis is the scarring of lung tissue due to the inhalation of asbestos fibers. It can result in shortness of breath, lung cancer, and mesothelioma. For these reasons, the use of personnel protective equipment like respirators is paramount for fire investigators and other personnel performing site work, especially once the potential for airborne asbestos is identified.
While asbestos was largely banned in many developed countries, it continues to be used in the United States in trace quantities in various forms of construction. The presence of asbestos in structure fires is well documented. At the fire scene, suspect asbestos-containing materials (SACM) may be present in materials in either friable (able to be crushed by hand and readily dispersed) or non-friable forms.
Some of the construction materials in which asbestos has been identified include:
• Caulk
• Plaster (skim and scratch coats)
• Roofing materials
• Joint compound and tape
• Gypsum board
• Ceiling tiles
• Vinyl and ceramic floor tiles of various size and their associated mastic
• Insulation materials
Formerly non-friable asbestos-containing materials may become friable due to heat, suppression, overhaul efforts of the responding fire company, and, potentially, during scene excavation and reconstruction efforts by fire investigators. For example, vinyl tiles that were formerly non-friable may curl or burn due to high heat resulting in areas of damage that are potentially friable. The resulting fire debris may itself be asbestos-containing material, which has the potential to become disturbed during scene processing.
Alternatively, friable asbestos-containing materials can be damaged and dispersed into a fire scene rather easily. For example, if a firefighter is checking for extension of fire and knocks down areas of plaster or drywall, there is a potential for friable asbestos-containing material to become damaged and airborne.
Since the presence of asbestos cannot be confirmed by the naked eye, laboratory analysis is needed to determine if materials contain asbestos above regulatory thresholds. Additionally, licensed technicians sampling for the presence of asbestos are often limited by safety conditions and are encouraged not to enter an area unless a competent person has deemed the workspace safe and structurally sound.
Damaged SACM construction is considered to be any material that deviated from initial and/or typical building construction. This could include material “knocked down” as a result of suppression or overhaul efforts, heat and/or smoke damaged materials, and others. Based on the nature of fire, often these construction materials may be damaged and should be considered friable in nature.
Taking Proper Precautions
With this in mind, insurance industry professionals, fire investigators, and other site personnel should consider an asbestos sampling program prior to conducting intrusive investigations or restoration activities.
To assess the potential for SACM at a fire scene, materials should be collected by licensed and/or certified asbestos sampling technicians consistent with local, state, and federal laws. The samples should be placed into appropriate storage containers, with sample collection and transport recorded on chains of custodies, and submitted to laboratories certified for asbestos analysis via polarized light microscopy and transmission electron microscopy techniques. Environmental industry standard sampling and decontamination practices should be observed to ensure sample integrity and personnel safety.
Asbestos will only be considered present in samples when observed at greater than one percent of total volume. It is noteworthy that while asbestos may be deemed present within a material, there is a potential for discontinuity of the presence of asbestos from like materials from room to room, based on when materials were installed and by whom. Therefore, the presence of a negative result of a sampled material may not necessarily mean that those construction materials are entirely void of asbestos throughout a structure. Thus, appropriate respiratory protection should be sought out of an abundance of caution for fire investigators and claims professionals alike even when asbestos has not been detected at a fire scene.
If there is a historical analysis of SACM at a fire scene, then asbestos-containing materials can be deduced to be present at a vast number of these locations. Studies have suggested the increased rate of mesothelioma in the firefighting community is associated with asbestos exposure. Additionally, once disturbed and mobilized as an airborne contaminant, asbestos can expose other areas of a scene not under investigation. One can reason that responders to fire scenes, like claims professionals and fire investigators, have a significant potential for exposure during the fire investigation’s scene processing, excavation, evidence collection, and reconstruction phases.
However, asbestos will not be the only potential contaminant encountered at the fire scene. Organic vapors, polycyclic aromatic compounds, heavy metals, respirable dust, and inorganic vapors like hydrogen cyanide and hydrogen chloride can also be present.
Considering the nature of fire scenes, NFPA 921 is accurate in stating that a fire scene is, by its nature, a dangerous place. It is with this in mind that the selection and use of personnel protection equipment like respirators is recommended during a scene investigation. Specifically, NFPA 921 notes, “The act of disturbing the fire debris can create dust and release organic vapors, which should be considered hazardous, and the investigator should be wearing a filter mask or an air purifying respirator with appropriate cartridges.”
The appropriate full or half-face respirator with cartridges, or even self-contained breathing apparatus, to protect against the contaminants at the site should be considered. A combination of organic vapor and particulate cartridges will likely be sufficient for the majority of fire scenes, although a site-specific hazard analysis may be appropriate.
In addition, the appropriate eye and skin protection should be considered in order to avoid potential health impacts. Furthermore, to avoid the transfer of contaminants from the fire scene, a decontamination procedure should be followed at fire investigations as outlined in NFPA 921. Following these recommended procedures reduces potential exposures of contaminants and creates a safer work environment for our industry.
Fire investigators and other parties, like companies involved in the restoration of the scene, should also consider a sampling program to identify the presence of disturbed asbestos at a loss location. Once asbestos has been identified through confirmatory sampling, an appropriate mitigation and cleanup program should be implemented. Regulatory requirements vary widely by region, so consulting with an expert knowledgeable in local, state, and federal statutes and regulations is a recommended best practice.