What is your wildland or wildland/urban interface (WUI) PPE designed to protect you against? Let me approach that question from a different angle: If I could promise you that there would never be a life risk (you would never have to enter a structure fire to save a life) at any structure fire, ever, from now until the end of time, what would your structure fire PPE look like? I bet your turnouts would be a far cry from the layers of thick, protective material, heavy helmets and boots that we wear today.
But of course, in reality, firefighters must enter dangerous environments to search for victims who have the potential to survive a structure fire. Our gear is therefore designed specifically to get us close to the fire so we can search nearly untenable areas, protect our heads from falling debris, shield our feet from nails and other sharp objects, etc. We know what this PPE is designed for. So again, what is your wildland/WUI PPE designed to protect you from?
In this article, I will review the basic reasons why firefighters wear PPE in the wildland/WUI environment. Through this review, you’ll be able to determine the objectives for wildland PPE for your own agency.
Trading Lives for Structures?
The easiest way to determine the real purpose of wildland/WUI PPE may be via a process of elimination. On a wildland fire, hand crews should be able to operate very close to low-burning (about knee-high), low-intensity fires for short periods of time. Their PPE should protect them from some level of heat exposure in that environment. (Note: Firefighters recognize that serious danger exists even when fires are burning with low intensity and low flame lengths. The context of this example is in terms of heat produced by flame, not the overall danger of the environment with all factors considered.)
I doubt that many firefighters would say that their wildland/WUI PPE is designed to get them close to a wildland fire that’s burning with any serious intensity. One key reason why PPE requirements have trended toward double-layer protection is that structure protection operations may require firefighters to get “closer than normal” to the fire. Really? The protection of property within a properly evacuated area “requires” us to get closer to the fire? I suggest firefighters rethink that statement.
On May 6, 2009, several burnovers occurred on the Jesusita Fire that caused serious injury to firefighters. At the incident briefing the next day, Kelly Gouette, the deputy incident commander, had strong words for the rest of us. Among other things, he said, “We are not here to trade lives for structures.” He was right. We need to remove the idea that the protection of property by staying and defending within a WUI zone is always the right thing to do. Don’t allow poor WUI planning or weak fire codes to compromise your safety, and don’t design your wildland PPE to protect you while you defend vacated property.
What Protection Do You Need?
NFPA 1977: Standard on Protective Clothing and Equipment for Wildland Firefighting, requires PPE to have a radiant protective property (RPP) of seven. This means it should be able to withstand .5 calories of heat for 14 seconds (in a laboratory environment) before an individual wearing the clothing receives a second-degree burn. The standard also states that adding another layer of PPE can add 30% more protection from heat. What does that mean for the average firefighter? What we first need to know is, how close can a firefighter get to a fire, and for how long, before they get burned? Put another way, what is a reasonable maximum exposure (RME)?
It’s a tough question to answer, because as every firefighter knows, the wildland firefighting environment can change quickly. Complicating the question is the fact that radiant heat transfer falls off at an exponential rate. This means that a firefighter will feel nine times cooler when standing three feet away from a stationary heat source, or four times cooler when standing two feet away. Of course, in reality, the heat source in a wildland fire is not stationary and other factors that influence fire behavior come into play. The lesson: Firefighter safety can’t be measured in feet. It’s measured by a firefighter’s ability to remain safely functional in a hostile environment. Sometimes, you need a lot of room to accomplish that. So in reality, the RPP standard and/or number of layers of PPE should not have a real bearing on how close firefighters can get to a wildland/WUI fire.
That said, there is a standard. There are three places we tell firefighters to go when they are threatened by a wildlfire: 1) a safety zone, where they shouldn’t need thermal protection; 2) a temporary refuge area, where they should need minimal thermal and ember-shower protection; and 3) a fire shelter, which we tell them to use as a last resort. The time standard used for firefighters to enter the shelter is 30 seconds.
The bottom line: In terms of thermal protection from wildfires, firefighters either require minimal thermal and ember-shower protection or they need an RME capable of allowing them 30 seconds of exposure to an environment that’s barely tolerable so that they can get into their fire shelters. To give an example, CAL-FIRE has determined that their RME is one foot away from a theoretical, stationary wall of fire (1 meter high x 10 meters deep x 100 meters wide) for a minimum of 49 seconds. This theoretical situation calculates to an RPP of 10.
Clothing Protection
Further developing WUI/wildland PPE requirements, the law (OSHA) and the NFPA require PPE to meet specific fire-resistive requirements and for station uniforms to “do no harm” to the firefighter. When the standards are reviewed, you’ll notice that they pay attention to the performance of the PPE and the station uniform separately. They do not take into account the performance of the complete clothing ensemble.
Departments that wear two layers of wildland PPE typically require the layer underneath to be their station uniform (typically Nomex pants and a cotton T-shirt). In this case, the outer layer definitely protects the inner layer from damage incurred by fighting fire. The down side of this strategy: When the layer underneath, the station uniform, becomes saturated with sweat, it turns into a “sweat blanket,” restricting air flow to the body and severely inhibiting evaporative cooling. If you’ve never worn this type of configuration, put a cotton T-shirt underneath an athletic T-shirt (such as UnderArmour) and run a 10K. After a while, you’ll notice the “sweat blanket” effect.
Note: Cotton was the PPE material of choice a long time ago, not because it wouldn’t burn, but because it didn’t stick to you as much when it does burn, and it was more comfortable (until it gets saturated with sweat) and less expensive than other fabrics available at the time.
The point: In PPE selection, agencies must pay attention to the complete firefighter clothing ensemble and how it works (or doesn’t work) together. If agencies only focus on meeting legal standards, they miss many significant impacts.
Injury Prevention
It’s well known that wildland firefighting is a lot of hard work. Firefighters spend their day lugging packs, hand tools and hoselines up steep terrain, often amid high temperatures. So it comes as no surprise that heat stress is the leading cause of injury to wildland/WUI firefighters.
Physical exertion, particularly in high temperatures, puts stress on the heart, causes the build-up of damaging internal heat and eventually reduces the brain’s ability to make sound decisions. Firefighters need and deserve athletic-level PPE that performs well in this type of extreme environment, wicking sweat away from their bodies, preventing it from saturating their clothing and preventing airflow constriction.
From a manager’s perspective, our job is to keep our firefighters working safely throughout their shift. This means that we must be thoroughly informed about what causes injuries to our firefighters, make accurate assessments of risk and clearly communicate our expectations when in the field. If we don’t support our firefighters with proper information and guidance, many will continue to operate in a dangerous environment, which may cause them to overexert and injure themselves.
The point: In PPE selection, wildland firefighting requires long periods of exertion in extreme environments. Agencies must require their clothing ensemble to be somewhat athletic in its ability to cool the firefighter and wick moisture away from the body so that it can provide evaporative cooling while it dries. The ensemble should also be flexible and constrain movement as little as practical to lessen physical exertion due to clothing resistance.
The Answer Is …
Now that I’ve discussed some of the benefits and limitations of wildland/WUI PPE, what is the answer to my first question? To put it simply, wildland PPE should be considered a complete clothing ensemble and designed to support firefighters so that they can work safely in a wildland/WUI environment during their shift and throughout their career. It prioritizes the risk of physical stress over the risk of thermal injury resulting from external burns. It also provides protection from wildland-related physical injuries, such as cuts, scrapes, falling objects, stepping hazards, etc.
Risk Assessment
By law, each fire department must decide on the specific purposes of their wildland PPE, which will be determined by where they live and what types of fires they will most likely be exposed to. This assessment of risks helps departments also decide on how to mitigate those risks. Few fire departments have a written risk assessment for their chosen PPE. Without this document and planned mitigations, the door is left open for “creep,” or normalization of deviance, to occur in terms of PPE specifications.
If you’d like to start a risk assessment for your department’s PPE, I’ve covered the basics in this article, so use them as a starting point. Below are a few additional points you should address when creating a PPE risk assessment:
- What are your typical operations in the WUI/wildland environment?
- What normal threats do your employees face when operating in that environment?
- What is your current station uniform configuration? How does that garment integrate with PPE?
- How do you prepare your employees for a rigorous, high-heat shift?
Once the threats to your employees are identified for the stated WUI/wildland environment, describe how your agency plans to mitigate each risk. Combined, those mitigations form the basis of administrative and operational policy for employees working in that environment.
The Next Big Thing?
The next big thing in terms of wildland/WUI PPE will be significant advances in fabrics with improved thermal performance. Manufacturers such as PBI, Tencate and others are currently working to produce more “athletic” wildland/WUI PPE materials that maintain a reasonable standard of external heat protection but also feature a high-performing evaporative cooling component. The improvements in these materials stem from the fire service’s realization that the impacts of physical stress on wildland/WUI firefighters are much wider reaching than previously thought.
Wildland/WUI PPE provides protection from many of the elements encountered on a major wildland/WUI fire; however, it’s important to remember that it’s not like structural PPE; it’s not going to allow firefighters to get extremely close to the seat of a major fire. To truly understand what your department gets and needs from its wildland/WUI PPE–and the difference between the two–you must first ask, “What is our wildland PPE supposed to do for us?”
