The importance of safety in wildland and wildland/urban interface (WUI) firefighting is clear. Less clear, however, is how we, as professionals, should address cardiorespiratory safety in those environments.
In entry-level classes, all firefighter medical classes and most annual refreshers, students learn or are reminded that breathing in superheated air has an immediate and significant detrimental effect. Even in cases of extreme exposure, such as a burn-over, firefighters who survive the superficial burns they suffered sometimes die due to significant inhalation of superheated gasses.
Clear standards have been established to prevent respiratory issues when firefighters are exposed to smoke, particulate matter and airborne toxins during indoor firefighting efforts. Unfortunately, clear standards have not yet been developed to protect firefighters from those same exposures in an outdoor environment. Further, there are hazards with smoke and toxin inhalation that are less obvious, but have a significant long-term effect on firefighter health.
In this article, I’ll discuss both the obvious and the hidden dangers of those exposures, highlight some of the research on this subject, and explore how standards might address the cardiorespiratory safety of wildland firefighters.
The Research
As noted within the guiding document of the IAFC/IAFF collaborative Wellness Fitness Initiative, cardiorespiratory issues remain one of the three leading causes of death and disability in the fire service. Some studies have shown that coronary heart disease and cardiorespiratory-related factors are responsible for as many as two-thirds of firefighter deaths, though most suggest that number is just below one-half.
Long hours and inconsistent shifts, periods of high-intensity work preceded and followed by periods of rest, and exposure to human suffering and emotional trauma are cited as contributing factors, as are irregular sleeping habits, infrequent physical activity, poor dietary habits and exposure to smoke particulates and toxins. Constant variations in stress levels, intense physical demands and exposure to chemicals and toxins have been shown to increase a firefighters’ susceptibility to cancer, lung disease and heart disease. There is also evidence that suggests that exposure to fine particulate matter has, in some cases, led to myocardial infarction.
Most of these studies have focused on firefighter deaths in general, so what remains to be quantified is the significance of smoke exposure within wildland firefighting operations. One thing that is certain: During wildland firefighting operations, firefighters are exposed to smoke and other airborne toxins that might have a physiological effect on them. There is also no question that routine exposure to these byproducts is harmful in many ways; it causes damage to the airway and ventilatory systems, as well as damage to the cardiac muscle and vessels of the body. Routine or significant exposure can have a cumulative effect on cardiorespiratory wellness, so we know exposure should be minimized through whatever means are available.
The NWCG Position
The adverse health effect of smoke is something that has been studied by many, including those tasked with setting protective standards for wildland firefighting. In 1997, the Missoula Technology and Development Center completed a study on these hazards, which was inspired by the National Wildfire Coordinating Group (NWCG). To my knowledge, this was the first organized study, but others have happened since.
The NWCG study indicated that less than 5% of wildland firefighters were exposed to more than the acceptable limits of smoke particulates, aldehydes and carbon monoxide established by the Occupational Safety and Health Administration. The NWCG group also found that the use of respirators imposed specific burdens upon wildland firefighters–limiting their work capacity (due to the weight of the respirator), causing increased heat stress, and making it more difficult for them to breathe. The conclusion of this study was that the routine use of respirators in wildland firefighting should not be required, but it did suggest modifications in strategy and tactics to reduce exposures.
In recent years, the NWCG assembled a group now called the Smoke Exposure Task Group, which has been charged with examining the hazards of smoke and the suggested protective measures. Although efforts are still underway to consolidate the existing data, the group noted that most studies have focused on short-term effects of smoke exposure, and that the data on long-term effects aren’t sufficient to draw reliable conclusions. They suggested that the collection of long-term data should be continued to allow for proper analysis.
That being said, the task force’s first recommendation was that administrative and engineered controls be exhausted prior to the application of respirators in wildland operations. These measures include:
- Physically avoiding areas of high smoke exposure.
- Strategically placing firefighters and fire lines where exposure will be minimized.
- Locating incident command posts and incident base camps outside of areas where smoke naturally collects.
- Monitoring carbon monoxide and other toxic gas levels whenever exposure is a threat.
The task force’s second recommendation was that all firefighters and managers be trained to include the risk of smoke exposure in their risk management continuum and to recognize the symptoms of exposure.
Regarding the use of respirators, the task force concluded that the need for respiratory protection would have to be evaluated and determined by each individual responding agency–no single standard could, or should, be created.
The recommendations from this group have further been expanded and published in the 2012 NWCG publication, Guidance for Monitoring and Mitigating Exposure to Carbon Monoxide and Particulates at Incident Base Camps (www.nwcg.gov/general/memos/nwcg-006-2012.pdf). The information is organized into three main categories for all firefighters to understand:
- The signs and symptoms of exposure
- Methods used to reduce smoke exposure
- Safe exposure levels for personnel operating on the fire line or in base camp
The Existing Standards
Indeed, there are standards that outline the expectations of respiratory protection for firefighting and rescue operations. NFPA 1852 explains how an SCBA should be selected for use in atmospheres that are immediately dangerous to life or health, and NFPA 1971 explains how the protective ensemble can be used for structural and proximity firefighting. NFPA 1977 focuses on the protective ensemble for wildland firefighting, but specifically excludes anything on respiratory protection.
Firefighters generally understand that using most types of respirators or an SCBA in wildland situations is questionable. There are certainly occasions, specifically when doing WUI firefighting or structural protection, when the hazardous exposures would warrant the use of an SCBA. However, on most wildland fires, there are few resource types who are within convenient reach of an SCBA and/or are performing tasks that would not be significantly impeded by wearing one. Furthermore, respirators, such as filter masks, are designed to filter out particulate matter, but do not protect against heated air inhalation, and are not designed to filter out airborne toxins found in smoke and all of its byproducts.
There is one standard that specifically addresses respiratory protection in outdoor firefighting: NFPA 1984: Standard on Respirators for Wildland Fire Fighting Operations, which was published in 2011. In essence, this standard specifically outlines what would be required if a manufacturer does decide to develop and sell a wildland fire respirator. However, it remains unclear whether any companies manufacture a wildland fire respirator that meets those specifications. Products such as the popular “Hot Shield” are commercially produced, but they are not intended to serve as a true wildland fire respirator; rather, they are protective shrouds with a built-in or exchangeable filter.
The National Institute for Occupational Safety and Health (NIOSH) has two rules that are relevant to this discussion:
- 42 CFR Part 84 addresses the approval of respiratory protection devices. This standard identifies two broad categories of respirator: “Air purifying respirators” that operate by removing contaminants as air is passed through an air purifying element; and “atmosphere providing elements” such as an SCBA. However, this standard does not include a recommendation for what, if anything, should be used in wildland firefighting.
- 29 CFR Part 1910.134 contains information for employees about respirators when their use is not required. If employees choose to use a respirator, a copy of this standard should be consulted.
What You Can Do
Although the research does show that wildland and WUI firefighters are exposed to hazards from smoke, there is still no standard that requires the use of respirators in wildland/WUI firefighting, and no commercially available respirators that meet the potential need. The tool of choice for centuries has been a bandana; evidence suggests that its effectiveness is marginal, at best. Clearly, something is better than nothing, and given the choice of bandana (shroud) or no bandana (no shroud), wildland firefighters are encouraged to use one. However, it should not be assumed that this limited tool is providing true respiratory protection.
For personnel who have access to an SCBA (e.g., structural protection engines), perhaps there are times where their use is warranted. However, the limitations imposed by their weight and limited service life must be noted, and should create apprehension about their potential use.
As it stands now, and until a clear and enforceable standard exists, the best way to provide respiratory protection to firefighters during wildland firefighting operations is to limit their exposure to smoke and its byproducts by having good situational awareness and making good leadership decisions about where and how long resources are deployed.
