Safety & Health

Fire Smoke: The Hidden Dangers

Smoke must be our number one adversary

Using atmospheric monitoring equipment to check the atmosphere. (Photos by author.)

By Jason Krusen

Fire service personnel are exposed to smoke and the products of combustion at varying levels throughout their time as a firefighter or first responder. Whether you are a member of a busy urban fire department, a volunteer with a slower rural department, or an EMT/paramedic with the local rescue squad, you are likely to be exposed to fire smoke on numerous occasions during the course of a career in public safety as a firefighter or other first responder. Much like the population in a community, a person’s affiliation with the fire service also can determine the amount of exposure to fire smoke, whether you’re a firefighter, driver/chauffeur, command officer, or administrative officer. Furthermore, the length of career, diet and exercise, the personal protective equipment (PPE) we use, and the actions we take both on and off the fireground all have a bearing on our health as first responders. “The National Institute for Occupational Safety and Health (NIOSH) recently undertook two large studies focused on firefighter cancer and concluded that firefighters face a 9 percent increase in cancer diagnoses, and a 14 percent increase in cancer-related deaths, compared to the general population in the U.S.”1

As firefighters, we are aware we will be exposed risks and we are taught from the first days of our training to be aware of those risks and how to better understand them. By understanding the risks, we are better prepared to make informed decisions about our successes in navigating the risks. This should be done no matter what the type or severity of the incident, whether it is crossing the street to check the driver of a minor motor vehicle collision, advancing a hose line down a hallway, raising a ladder to the second story on the backside of a structure of a dimly lit scene, or overhauling in a smoke-filled environment.  While we are not likely to be able to avoid the risks we can certainly manage or reduce them, but to do so we have to understand them. 

There is a wealth of research being conducted like the study Cardiovascular & Chemical Exposure Risks in Modern Firefighting and so many more that are helping responders understand the threats and the increased long term health risks and operate more safely.2 However, often when someone says we need to operate more safely, people take to the defensive in fear someone is telling them they are too aggressive; this is not necessarily the case. We can be both aggressive and safe; the two can occur in the presence of one another. When the two occur together, the result is a well-trained fire department that operates efficiently and safely no different than a well-trained sports team, military component, or surgeon.

The smoke we are exposed to needs to be our number one adversary, not the fire. Fire is a threat to the building and the smoke is a threat to us. Yes, the fire threatens the integrity of the structure, which in turn threatens the firefighters, but if we do our jobs as trained, the structural components do not affect us. However, the smoke and products within it affect us every time regardless. Fire is complicated, and we cannot tell by looking at the smoke what its level of toxicity will be. Just like we need to treat every call as if it were an actual fire, we need to treat all smoke as if it is the most toxic. The 2010 UL report Firefighter Exposure to Smoke Particulates states,“Combustion of the materials generated asphyxiants, irritants, and airborne carcinogenic species could be potentially debilitating.”3 Furthermore, these products were present in both small and large fires with synthetics generating larger quantities. Individually, these toxicants were dangerous, but when paired up there were synergistic effects coupled with long-term health issues from repeated exposures. The fire service needs to continue conducting research and educating the current and future firefighters to better understand not only how we are experiencing these long-term health effects but how to prevent them.

The use of respiratory protection is a leading safeguard for firefighter protection and, unfortunately, one of the most underused pieces of PPE available to every firefighter. The use of self-contained breathing apparatus (SCBA) and practicing air management are important parts of our safety on the fireground both short and long term. As the fire service trains firefighters that SCBA is a vital piece of the PPE ensemble, we also need to educate them on why it is so important and continue to emphasize the realities of fire smoke exposure not only once we start riding the apparatus but throughout our recruit training. More attention needs to be paid to all fires, even those conducted in training. A training cadre is often a core group of individuals who are exposed to these contaminants for an extended period of time for days on end, so the same practices being implemented on the street need to be used in training.4

The use of atmospheric monitoring equipment on the fireground helps provide a better understanding of what the air firefighters are breathing actually looks like on the scene. Often as first responders, we think if it looks clear then it is safe, but this is not always the case. When firefighters are working inside a smoke-filled environment, they typically are wearing their SCBA and full PPE; however, when they are operating outside but in close proximity to the fire building, they tend to get complacent. Using atmospheric monitoring in these areas, especially if a safety officer is designated on the scene, can help bring attention to these areas (photo 1). This includes but is not limited to operating above the fire, at the pump panel, or at the command post.  Sometimes simply being made aware of or reminded of the need for SCBA is all that is needed. Two areas when SCBA should be used but that are typically overlooked are when operating on a roof and when performing overhaul on the exterior. 

Photo 1. Using atmospheric monitoring equipment to check the atmosphere. (Photos by author.)

It is easy to try and justify not wearing the SCBA for just a minute or two while performing a short-duration task, but what firefighters often fail to realize is the task we thought would take one minute turns into three minutes, or that the one-minute task now leads to another task that takes us closer to the smoke. This behavior ends up becoming an acceptable behavior. Now take all of the simple one-minute tasks and add them up over a 25-, 30-, or 35-year career. Wearing an SCBA in these scenarios greatly increases a firefighter’s protection.

By simply placing a multigas atmospheric monitor on a safety officer, incident commander, or pump operator, those individuals can be alerted to elevated levels based on the sensors in the monitors and act accordingly. This act could be as simple as taking a few steps back or upwind or even perhaps donning an SCBA depending on your task. Following the active interior operations associated with fire control and ventilation monitors can be employed on the interior to let crews know when it is safe to operate without SCBA. Personnel should also be aware of the particulate issue; so, if extensive overhaul is being conducted, SCBA is still recommended even though the monitors are within normal ranges. Where this can be beneficial is for smaller fires, fires in large buildings, when operating on multiple floors, or during the investigation phase of the incident. Lastly, it is a great tool to use before turning the property over to the owner/occupant to ensure the space is safe.

Before leaving the scene, personnel should work on minimizing the contamination of the products of combustion they are exposed to. The PPE we wear is not only exposed to overhaul debris, which can contain contaminants and carcinogens such as lead and asbestos, but also particulates like soot as well as fire gases that continue to off-gas long after leaving the scene. By simply separating ourselves from the contaminated gear, we greatly reduce our risk related to continual exposure. This can be achieved by bagging the gear on the scene, and if the crew needs to respond to another call, the bag can simply be opened up to access the gear. 

Another action that can be performed based on the climate is an on-scene wash-down. This simple action of hosing off the PPE ensemble can increase the effectiveness of reducing the exposure to contaminants.  There are many new configurations available both commercially manufactured and home-built. Decontamination or wash-down using dish soap, water, and scrubbing is the most effective method for removing polycyclic aromatic hydrocarbons (PAHs) from PPE while still in the field. It is more effective than dry or forced-air decon but based on the climate a water-based wash-down/decon may not be possible.5 On-scene personal hygiene measures such as wipes and hand washing can address the most grossly contaminated areas of face, neck, and hands (photo 2). This is beneficial while on the scene with achieving quick removal of the bulk products but does not replace the need for a shower.  

Photo 2. Use of wipes before rehab in conjunction with hood swap.

Following on-scene wash-down activities that address the PPE ensemble (turnout gear and SCBA), there is still the more definitive act of decontamination to the responder that needs to take place. It is even more important that the personnel take part in hygiene measures such as showers and uniform changes when back at the station or at home. If at all possible, responders should shower and wash clothes at the station to reduce the risk of contaminating personal vehicles or home spaces, but some volunteer stations may not be equipped with shower and washing facilities.  

It is important to remember that decontamination is the act of reducing contamination, not necessarily eliminating contamination altogether. One should not discredit any action that can be employed to reduce the contamination because it is not the most effective or because the preferred method is not available. Take any available steps to reduce contamination as responders migrate from the structure to rehab then to the rig and then back to the station. It is best to have multiple options available based on the situation and the climate being faced.

Following the incident and once personal hygiene has been addressed, PPE care and maintenance, as well as tool cleanup, still remain. If a second set of gear is not an option, then steps should be made to clean the gear at the end of the shift before then next shift/tour is started (photo 3). Other options such as hood swap programs are also great ways to reduce the contaminant to personnel and ensure everyone has a clean hood. Tool cleanliness including radios must not be forgotten to ensure maximum reduction of contaminant.

Photo 3. Bagged contaminated gear ready to be washed.

While there are many emerging innovations and trends in the fire service, not everything requires new pieces of equipment or widgets. Many think the clean cab concept requires new apparatus, but features of the clean cab designs can be incorporated into existing apparatus. The decision to only carry clean PPE and SCBA in the cab can be initiated with the existing apparatus (photo 4). Dirty gear can be stored on the tailboard or in compartments for the trip back to the station once soiled. Instead of purchasing commercially made wash-down/decon kits for apparatus, simple homemade kits can easily be produced. Change in hygiene and decontamination procedures both on the scene and at the station can also be incorporated easily and cost effectively. The problems we are facing are more about behavioral changes and can start to be implemented today.

Photo 4. Contaminated gear stored in an outside compartment.

Fire smoke continues to affect the fire service more aggressively than in years past with the continued additions of synthetics in our construction materials and household items. Having a better understanding of how the smoke affects firefighters and the ways to minimize the exposure we face will better protect us in the long term. In the meantime, we need to better use the PPE and equipment we have and learn to take better care of them so we can reduce the repeated exposure.


1. National Fire Protection Association. (2019, December 17). News & Research. Retrieved from

2. Horn, G. K. (2015). Assessing the Cardiovascular and Chemical Risk Faced by Firefighters. Champagne, IL: Illinois Fire Service Institute.

3. Fabian, F. B. (2010). Firefighter Exposure to Smoke Particulates. Northbrook, IL: Underwriters Laboratories Inc.

4. Fent, K.W. (2019). Understanding Airborne Contaminants Produced by Different Fuel Packages During Training Fires. Journal of Occupational and Environmental Hygiene, 532-543.

5. Fent, K. W. (2017). Contamination of Firefighter Personal Protective Equipment and Skin and the Effectiveness of Decontamination Procedures. Journal of Occupational and Environmental Hygiene, 801-814. doi:10.1080/15459624.2017.1334904.

Jason Krusen is a deputy chief in the Charleston (SC) Fire Department with more than 25 years of experience. He has a bachelor of science degree in fire and safety engineering technology from the University of Cincinnati. He is currently in the NFA Executive Fire Officer Program. He is an instructor for the Fire Smoke Coalition and E-Med Training Services.