Can lighter PPE make firefighters safer?
The fire service might benefit in many ways from garments that are lighter and more breathable
By Mike McKenna
One of the most common comments that I hear from firefighters is that they are too insulated from the heat of the fire. At the same time, the fire environment is hotter and more dangerous than ever and some argue that even higher levels of thermal protection are needed.
NIST research has described the increased dangers to the firefighter from increasing fire loads and intensity over the past decades, caused by the introduction of synthetic home furnishing materials. Is increased protection needed and what is the cost?
Maybe it is time for a different look at the role of PPE in situational awareness and maybe for changes to the NFPA performance requirements. Changes that might make firefighting safer, keep firefighters healthier, reduce the number of heart attacks and provide a better quality of life after retirement.
Comfort and weight
Most current protective philosophies are geared around protecting firefighters during the worst-case scenario — flashover. However, in addition to flashover protection, firefighters also want garments that will be comfortable, lightweight, and both insulate them from the heat, and allow them to feel it at the same time. They want garments that are stylish, and easy to don and doff with large pockets.
TPP (thermal protective performance) is a value placed on thermal protection. TPP is essentially the amount of thermal protection provided by the lay-up of outer shell materials, the moisture barrier and the thermal liner. The current TPP minimum of 35 equates to a second-degree burn in 17-1/2 seconds in a flashover lab condition. The THL (total heat loss) of 205 is the breathability of the same lay-up as compared to a THL of 100 that is considered non-breathable.
Interestingly, firefighters do not often enough take advantage of the lighter systems that are closer to the TPP of 35 — which is the current minimum value — that may provide at least some of the desired features and benefits. Instead, firefighters routinely choose TPP values that are on the upper end of the scale and only provide a minimal acceptable THL.
Firefighters choose these higher TPP values and then complain about being over-protected. Firefighters can specify as high a TPP as possible as long as the associated THL value is above 205. Perhaps the fire service mindset needs to reevaluate protection with consideration given to the idea that being over-protected is just as dangerous as being under-protected.
The current PPE is designed to protect firefighters in the worst-case scenario, but what about the rest of the time? Might the fire service benefit in the long run from lowering the TPP and raising the THL to make the turnouts less stressful to the firefighter?
Any idea of altering the TPP and THL presumes that the values of THL and TPP are scientifically valid and translate directly to protection levels that they are of quantifiable benefit to the firefighter. I am not suggesting that TPP and THL are not valid or do not directly translate to levels of firefighter protection, but to raise discussion.
If the NFPA standard TPP was lowered to 32 and a maximum was set at 38 and the THL is raised to 270, might the firefighter expect to feel the heat sooner and be more aware of the surroundings?
In addition to improved situational awareness, a lowered TPP range could provide the firefighter PPE options that could keep PPE lighter and more breathable. Instead of relying on the protective hood to become saturated, the firefighter would feel heat in the shoulders and other compressed areas sooner and in turn could be more cautious and be more aware.
Overall, raising the THL to 270 from 205 would theoretically lower the stress on the firefighter. The THL, the breathability, of course, is a lab number. The pivotal research on THL, Field Evaluation of Protective Clothing Effects on Fire Fighter Physiology: Predictive Capability of Total Heat Loss was completed in 1998.
The study was completed and put some science behind the concept of breathable garments. The conclusion was that a THL of 205 was both beneficial and achievable when the study was completed in 1998.
It is now 2010 and research needs to be done to evaluate some of the new composites and technologies that have been developed or might be waiting in the wings because of the current limitations.
The upside is that if the relationship between THL and TPP is real and actually benefits the firefighter directly, then a new generation of higher THL and lower TPP garments could reduce the physiological stresses on them. This would make the firefighter more productive on the fireground and have a positive affect on the long-term quality of life for firefighters.
There could be downsides. One is the potential for increased burn injuries as firefighters struggle adjusting to the limitations to the new PPE. Firefighters would feel the heat sooner and may continue to push limits citing the ability to do it in the older PPE. While that is important, it is probably the same scenario that previous generations of firefighters faced when they moved from cotton duck and flannel lined PPE to newer fire-resistive materials.
Nevertheless, continually developing PPE only around the worst-case scenario is limiting to the fire service and firefighters lose awareness and suffer from heat stress-related issues. Firefighters should never use body parts for situational awareness, but the feeling of heat in your PPE is an important tool.
The fire service might benefit in many ways from garments that are lighter and more breathable. At the end of a 30-year career, would the firefighter that had spent their career in a 32-38/270 structural garment be healthier? The fire service averages 100 line-of-duty deaths per year mostly from heart attacks, leading one to believe that any improvement that lowers the physiological stresses to the firefighter is a benefit.
Is it possible that firefighters are in more danger by being over-protected? If a 32-38/270 garment is physiologically better than 35/205, wouldn't the fire service be better served in both the short and long term? Firefighters might be healthier, more effective and live longer and have better life after retirement.
In concept, this is something to think about. The fire service needs to raise the level of debate on ways to make firefighters more productive, safer and provide a high quality of live while working and in retirement.