DuPont’s Firefighter Garments Reduce Heat Stress, Avoid Exposure To Toxins

Among the ways, garments protect firefighters is by reducing the heat stress and discomfort created by the need to carry heavy gear. Making the garments more comfortable to wear means less physical stress. Garments also help to protect firefighters from the toxic elements in the fire environment.

The extent to which plastic materials can generate toxic smoke when they burn has previously been ignored but is now better understood.

Concerted effort to understand end user

As a manufacturer of fibers used in firefighting garments, DuPont makes a concerted effort to understand the end user of their products; that is, the firefighter.

They seek to keep the firefighter safer and to extend the time available to do his or her job safely. DuPont works with fabric and garment manufacturers to focus on minimizing the impact of the toxic environment.

Firefighter’s awareness

Multiple initiatives seek to make firefighters more aware of potential dangers and best practices

Awareness by firefighters of the negative impact of toxic materials has increased substantially. Multiple initiatives seek to make firefighters more aware of potential dangers and best practices to avoid exposure to contamination.

Organizations promoting greater awareness include firefighters’ unions, the International Association of Fire Chiefs (IAFC), and the National Fallen Firefighters Association.

Toxic smoke

For example, testing confirms that toxic smoke often affects firefighters in the neck and jaw area, where sweat promotes absorption of smoke particles.

A woven hood or baklava avoids the absorption, reflected in the NFPA Standard 1971, which makes particulate protection hoods mandatory. The Nomex Nano Flex hood increases the comfort of the gear. Avoiding toxic materials also includes no inclusion of per-and poly-fluoroalkyl substances (PFAs) in garment materials themselves.

Standards and Specifications

Testing is an area of focus for DuPont, which has the capabilities to test the layered structures firefighters are wearing. One tool is the Thermo-Man, a fully instrumented mannequin that tests the likely burn injuries of flash-over fires.

DuPont works with the NFPA, ISO, EN, and other standards committees to develop testing and certified standards to ensure the performance of firefighter garments. Fire gear is specified in each region according to a standard (minimum) performance. In many cases, garments out-perform the requirements.

Other variables

Other variables of firefighting garments include the fitting and weight

Other variables of firefighting garments include the fitting and weight. A less expensive approach might yield a garment that sacrifices comfort. Geographic and climate differences matter, too.

A firefighter in the North would prefer a different garment than in the South. Garments should be comfortable, lighter, and warmer in cold environments. On the topic of gender, garment makers offer female designs that are cut and shaped differently.

Garment makers evaluate the weight of the assembly, how well it protects against the heat, and the comfort. DuPont works with garment makers to test various materials and how they perform in fire garments. The company works with firefighter consultants in the U.S. and Europe who help them understand the language of firefighters.

Addressing Dangers of Toxic Materials

Cleaning fire gear of toxic materials is a challenge related to garments. Toxic materials on fire gear returned to the fire station can also expose the station environment to danger.

Changing logistics and processes are driving how gear is handled in the fire station environments. Some stations are designating black zones, gray zones, and white zones, depending on the level of contamination of the gear in those areas.

Washing and drying

More frequent washing of bulky, heavy gear helps to circumvent the impact of toxic materials, but repeated washing and drying can cause mechanical stress and resulting damage to a garment. DuPont collaborates with weaving mills and garment makers to develop fabrics and garments that stand up well to frequent washing.Toxic smoke particles and mandatory use of hoods on firefighters is translating into more washing.

As time goes on, the washing and decontamination process will likely become more professionalized with laundry companies stepping in to wash and handle the garments. Fire stations are not well suited to cleaning these garments.

Nomex Nano fiber

Nomex Nano Flex is a non-woven material that retains toxic and cancer-causing particles

Developed to address the growing problem of heat stress, DuPont’s Nomex Nano fiber is engineered to be thinner than other advanced flame-resistant materials. Nomex Nano Flex was developed to help make products like firefighter hoods more protective against particles without compromising comfort.

Nomex Nano Flex is a non-woven material that retains toxic and cancer-causing particles, and creates a particulate barrier. It also protects the firefighter from outside heat while cooling the firefighter by evacuating body heat.

Higher evaporation rate

Nomex Nano Flex has a higher evaporation rate. For the same thermal protection performance (TPP), it also has higher total heat loss (THL).

Combining protection, thermal performance and toughness, Nomex Xtreme Performance is the highest performance category of solutions for flame-resistant personal protective apparel.

Feedback from Firefighters

“If we have a new innovation, or want to share our developments, we go proactively to fire departments to ask: Will this help you or not?” says Alfons N. Held, Global Market Leader, Emergency Response, DuPont Personal Protection. There is a difference between lab testing and what firefighters experience in the real world.

Alfons N. Held adds, “We seek to understand what they need, and approach ‘lighthouse’ fire departments for guidance.” In any country or jurisdiction, there are fire departments – ‘lighthouse’ departments – that set the trends and work to evaluate the gear.

If someone in Florida is using certain gear, it might also work in Texas or Arizona.

The protection level

Areas of continuing research in terms of firefighter garments include making them more wash-durable

The question is: What protection level do we need? Given that level, departments seek to balance comfort with performance. Ironically, of the firefighters who die every year, some two-thirds of the deaths are attributable to overexertion, while less than 10% is linked to the fire/heat.

Areas of continuing research in terms of firefighter garments include making them more wash-durable, more comfortable (with higher evaporation) and more lightweight.

Complex systems

Garments can be complex systems; heavy turnout gear is a five-layer garment with each layer contributing to performance – the outer shell, the inner liner, a moisture membrane, and one or two thermal liners.

Sometimes attention is more focused on the outer layer of the gear with less awareness of the other layers and how the entire system works together.

Importance of station wear

In fact, protection of the firefighter starts at the skin, so station wear is important. “In our view, looking at all the layers on the skin and outwards is important,” says Alfons N. Held, adding “Firefighters wear various materials that are not always optimal.”

For example, a cotton undergarment might get wet from sweat, stay wet and not evaporate. Environmental impact is another concern among garment-makers. Can the materials be reused or recycled? Some countries in Europe ask that manufacturers take back garments after they are used.    

New Garments, New Needs

A special need is development of new garments that can perform at the wildland urban interface (WUI), where catastrophic wildland fires encroach on residential areas.

Design of gear for wildland firefighting has been lighter and does not include breathing systems. When fires reach residential areas, gear needs change. Wildland firefighters are not equipped to enter a structure fire and do not have adequate protection against carcinogens. New gear designs are needed that address both environments.