Jason M. Krusen: Atmospheric Monitoring on the Fireground

By Jason M. Krusen

Unfortunately, every one of us is or will be touched by the horrible news that someone we know or care about has cancer. We hope that it will not be a firefighter, but lately the news is filled with firefighter-related cancer. Cancer is such a complex disease, and there are new findings and advances every day. We are also learning of new ways to combat the disease; but in the meantime, we are continuing to lose brothers and sisters. As firefighters we need to do more to lower our risks. Cancer in the fire service cannot continue to be ignored. We need to make sure all firefighters understand the environmental and behavioral risk factors that can increase the likelihood of some cancers. As firefighters, we pride ourselves on protecting others and promoting safe environments, but are we neglecting our own safety in the process?

Understanding the risk factors for smoke-related illnesses and cancer will not prevent the illness, but it can lead us to take more seriously the need to take precautionary steps. The smoke we are exposed to and quite often breathe unnecessarily around the fireground is dangerous and loaded with toxins and carcinogens. The sooner we realize these dangers and start learning how to minimize our risks, the safer we will be. The reality is that we may never be able to prevent completely exposure to smoke on the fireground, but we can limit the exposure, determine the amount of time we remain contaminated, and better educate firefighters on the dangers of these exposures and those to which we will be subjected throughout our career.

It is much easier to prevent an exposure than to have to deal with the consequences afterwards. We can accomplish this quite simply by using our self-contained breathing apparatus (SCBA) (yes, the entire unit including the face piece) and properly donning all personal protective equipment (PPE) to limit the exposure when we are enveloped in smoke (photo 1). After the incident, we can limit the amount of time we are exposed to the contaminants by washing our gear, taking a shower immediately, putting on a fresh uniform, and cleaning our equipment and apparatus. Even in a perfect world and by following these steps, we will still be exposed to smoke. We must learn how to better control or reduce our risks if we cannot eliminate them completely.

Atmospheric Monitoring

Monitoring on the fireground will help us manage the risk by providing real-time information to help us make better informed decisions about how to operate on the scene. Because we cannot always prevent the exposure, we should use atmospheric monitoring to help alert us to the dangers around us on the fireground. Most departments have atmospheric monitoring equipment on their first-out apparatus, so the equipment is already in place in most cases; but we often overlook using this resource because we think it is only for hazardous materials calls.

Most firefighters would agree that a structure fire fits the definition of a hazmat-related call, although it is not the first description that comes to mind when we are asked to categorize it. Copious amounts of toxic and asphyxiating gases collect in a confined area, creating an environment that is immediately dangerous to life or health (IDLH). Because we spend a considerable amount of time operating within an IDLH atmosphere, it is important to understand when it is safe so remove our respiratory protection. Saying that “it looks clear” or “I think it is safe” without putting a number to it is no better than just taking a guess at what the quality of the air we are breathing.

Although the SCBA is an obvious choice during the initial phases of operation because of the smoke-obscured environment, it is quickly discarded–or at least its full use is greatly diminished–once the fire is under control. The use of ventilation to remove the smoke and gases has become extremely effective, but is the environment really clear once all the “smoke” has been removed? There comes a time when the structure or area in which we are operating no longer appears to contain smoke. Although there may be no visual indicator that smoke is present, that does not mean breathing the air will not be harmful. It is important to understand what is in “the smoke.”

What’s in the Smoke?

Smoke is not only the visual particulate of soot and water vapor, but it contains invisible gases as well. Gases such as carbon monoxide, which is colorless, odorless, and tasteless, is a prevalent gas found in smoke. These gases and toxicants wreak havoc on our bodies as we are exposed to them. Some gases cause us immediate harm and discomfort; others lie dormant in our fat cells and organs and continue to build up, leading to long-term ailments. Limiting exposure to the products of combustion and then reducing the amount of time the contaminants remain on our body are vital. Atmospheric monitoring is just another safety step that should become routine just like using an accountability system, wearing PPE and SCBA, or taking a shower when we return from the call.

When and Where to Meter

Atmospheric monitoring can be initiated by units early in the incident. Taking an expensive piece of detection equipment into a burning structure is not the likely starting point, but there are many places around the fireground where a meter can be extremely useful early in the incident. As units arrive on scene, they can position the meter at the command post to alert the incident commander (IC) if the post is too close to the scene. If the IC commands from the vehicle as many departments are starting to do, then perhaps the pump operator of the first-due engine could keep the meter. Perhaps the meter can be assigned to one of several people on the exterior, such as the rapid intervention team, as the members typically move around the outside of the structure, on-deck personnel, those staging on scene awaiting an assignment, or medical/rehab personnel (photo 2). This will allow personnel on the scene to understand if they are operating in a safe environment while on the exterior. If additional meters are available, they should be deployed in multiple locations.

Once the fire is under control and ventilation is underway, transition the meter to the interior of the structure. Do this once all the visible smoke has been removed. Firefighters have developed a false sense of security in thinking that the environment is harmless when all that remains is a light haze or a lazy smoke condition following the fire’s knockdown, and they prematurely remove their PPE and SCBA. This is a huge misconception. Never remove PPE without checking the atmosphere. Most of the gases have no distinguishing odor, and those that do will be masked by the smell of smoke. SCBA use while operating in the interior of a structure is the safest measure available to firefighters. Taking the meters in too soon, while there is still smoke present, is detrimental to the meter’s operation. The meter will likely alarm early in the operation because of the high concentration of smoke and gases and cause it to become saturated and work ineffectively. Continuous operation in these conditions will likely shorten the life expectancy of the sensor and generate maintenance issues in the long term.

There are, however, circumstances when keeping firefighters in full PPE including SCBA creates an additional danger of heat stress. Summer temperatures and high humidity in many parts of the country will create physiological concerns that need to be addressed by increasing work/rest cycles or rotating crews, if staffing permits. Prior to removing respiratory protection, check the atmosphere to ensure the safety of the personnel.

Meter Operation

Although preset alarm levels assist in making the meter easier to use from a basic user standpoint, it is always better to have a good understanding of the equipment you are using. A simple training session on how the meter works and how to properly use it is easy to put together and will pay off greatly in the end. If personnel use the meters more frequently, the meters will be checked more often, and the department is likely to see a decline in the number of  meters that are out of calibration or uncharged. The users need to understand monitoring techniques such as where to place the meter and how fast to move through the area being monitored.  There needs to be a happy medium with respect to meter placement. You do not want to keep the meter stationary, like affixed to your SCBA strap or wave the meter too fast and not allow it to sample any one area long enough. Personnel should meter high (arm raised above the head), mid-level (meter at waist level), and low (arm held to the side), allowing ample time at each level for the meter to sample (photo 3).

The reaction time varies according to the manufacturer and the sensor itself; this is another good reason to become familiar with the specific instrument your department uses. Traditional sensors (lower explosive limit (LEL) oxygen) may take 15-30 seconds to respond, whereas exotic sensors (chlorine, ammonia, hydrogen cyanide, and so on) may take upwards of 180-200 seconds. This is the reason you do not want to run through the structure or area being monitored: you may not allow ample time for the sensors to get a sufficient reading. Moving through the structure methodically and allowing the meter to properly read the atmosphere is the best method. If you enter a room and the meter reader starts to climb rapidly and the meter alarms, move to another room, and alert those responsible for ventilation of the issue. The high reading could indicate that the areas are poorly ventilated, but it may also mean there are smoldering remains that are generating gases.

Meter Configuration

The typical configuration used for fireground monitoring is oxygen, LEL, carbon monoxide, and hydrogen cyanide, but the latter is not a requirement for atmospheric monitoring on the fireground (photo 4). Prior to 2007, atmospheric monitoring on the fireground was an unusual occurrence, and the typical configuration of meters was similar, but a hydrogen sulfide sensor was used in the place of the hydrogen cyanide sensor. If your agency is still using a hydrogen sulfide sensor, the meter can still be used for fireground monitoring; it just will not be able to test for hydrogen cyanide. Some departments are still using the hydrogen sulfide configuration because it is likely to be present in confined spaces. My department realized that we were far more likely to run a call with smoke than confined space entry. Thus, we started replacing our hydrogen sulfide sensors with hydrogen cyanide sensors on the engines and ladders and left the rescues and hazmat unit with the hydrogen sulfide sensors.

Each department needs to determine the action levels. Some departments use the National Institute for Occupational Safety and Health Recommended Exposure Limit (REL) for determining action levels at which it is safe to remove SCBA. Others reduce the number arbitrarily, making it safer; and still others have determined that nothing less than zero will be acceptable.

Creating Policy and Buy-in

Your department may need a strong policy or guideline pertaining to atmospheric monitoring on the fireground, but keep in mind that the policy or guideline is only a piece of paper. It is important to educate the personnel on why they need atmospheric monitoring on the fireground. The monitoring is used as a safety measure to ensure we not only go home today but that we live long enough to enjoy our retirement and our years beyond the firehouse. It does not end with atmospheric monitoring. It is also important to discuss the use and care of PPE, proper air management, and good personal hygiene, to name a few considerations. Getting personnel to buy in on the need for the policy will make atmospheric monitoring a success.

We cannot look for every gas or compound found in smoke, but we can start by looking at those that are not the most common but also those for which we have a means to treat medically. A common question often asked is why do most departments look at only a few gases, or why do we test only for a specific group of gases. This can be looked at much like the history of seat belts. When the lap belt was first required a little more than 50 years ago, there probably were people who thought it could be designed for more safety. Later the three-point seat belt came along; again, its effectiveness was questioned. Then along came the supplemental restraint system/air bag, making the automobile even safer. We need to do the same and use the technology we have accessible to us today while looking for, or developing, what we will use tomorrow instead of refuting the effectiveness of what is now available something better comes along.


Jason M. Krusen, a member of the fire service for 20 years, is the special operations chief for the Columbia (SC) Fire Department. He is the president of the Fire Smoke Coalition and has an associate degree in fire service administration. He is a planning manager with State Urban Search and Rescue Team SC-TF1, the team coordinator for the department’s Type II Collapse Search & Rescue Regional Response and the WMD/Haz-Mat Team SC-HM5 in Columbia. He is also the project manager and instructor for E-Med Training Services, LLC in Columbia, South Carolina.