highly engineered nonwovens play an important role in defending NYC’s ‘bravest’

By Michael N. Ciampo
rnFirefighter City of New York Fire Department (FDNY) New York, NY

Firefighting is one of the most dangerous occupations in modern society and the most threatening problem to firefighters and their safety equipment is the hostile environment in which firefighting takes place. Due to an increased use of modern plastics and other synthetic materials, this environment has become even more dangerous. Such conditions may cause fires to burn at higher temperatures, producing higher levels of poisonous gases (both flammable and lethal) and increasing the speed of flame spread. These developments also spurred an increase in the number and severity of burn injuries to firefighters caused by personal protective equipment failure.

Such changes over the last 20 years have helped to underline the need for new, redefined and updated personal protective equipment. The firefighting industry has experienced a major facelift in safety equipment, particularly due to the technological advancement of fibers and fabrics. Updated technology has enabled firefighters to be better equipped with new and improved personal protective equipment (PPE) and firefighting gear. These important contributions have enabled firefighters to perform required tasks with greater ease and increased safety benefits. Some of the major manufacturers and products responsible for these advancements include DuPont’s “Nomex” and “Kevlar,” Celanese Acetate’s “PBI Gold,” W.L. Gore’s “Gore-Tex” and “Cross-Tech” and BASF’s “Basofil.” Although technology has taken great strides, continued research and development efforts are required to make firefighting products more durable, lightweight and safe.

Personal Protective Equipment
rnPersonal protective equipment has changed dramatically in the past two decades. Long gone are the days of wearing rubber jackets, rubber boots and plastic gloves. Today, after years of testing, refinements, data collection and “on the job” evaluations, the National Fire Protection Association (NFPA) has set stringent standards for personal protective equipment. The result is that today’s firefighter is better equipped than his predecessors.

Personal protective equipment is now designed as a two part system, with the first level of protection being the multilayered bunker or turnout gear. This is the visible layer people recognize when they see firefighters in action. The second level of protection, which is worn beneath the bunker gear, is the firefighter’s work uniform, also especially formulated to add to his protection. Many volunteer firefighters are not equipped with work uniforms. However, bunker gear alone does offer the minimal amount of protection needed for firefighting operations.

Bunker Gear
rnBunker gear is now the norm in firefighting safety equipment across the U.S. Unfortunately, many smaller fire departments are operating without bunker gear, which is largely due to insufficient funds for this expensive ensemble. Complete bunker gear costs range from approximately $500-$1500. Fortunately, in most major cities where the fire workload is higher than in rural areas, the changeover to bunker gear is all but complete.

Bunker gear is a two-piece ensemble made up of a coat and pants. The coat and pants are three-layered garments, which often include a nonwoven liner. The layers consist of the outer shell, the thermal liner/heat barrier and the moisture/liquid barrier. All three layers contribute to the protection level necessary to defend the firefighter. The three layers may be made of different materials and percentages of materials.

The outside layer, known as the outer shell, is made up of materials such as Kevlar, Nomex or PBI. One particular brand on the market made by Fire Dex features a 40% PBI and a 60% Kevlar outer shell, while another brand produced by Bodyguard is constructed with 7.5 ounce superior fire-retardant “Nomex IIIA Aramid” for defense against thermal exposure. The outer shell must be the most durable layer of the bunker gear because it is exposed to very high temperatures (200-1500°F). It must also be puncture and tear resistant from sharp glass and nails. Lastly, in combination with the other layers, it must prevent contamination from hazardous chemicals, fuels and bodily fluids.

The next two layers—which may be manufactured through various processes including stitchbonding, needlepunching, specialty highloft or quilting—are equally important but they do not face the same rigorous conditions faced by the outer shell. The thermal liner and moisture barrier are mentioned together because they are commonly sewn together and attached to the outer shell by “Velcro” and snaps. The thermal liner, often a nonwoven, is the secondary barrier guarding against high heat temperatures. Thermal liners may be sewn to a number of types of liquid barriers, with the liquid barrier preventing water, chemicals and blood-borne pathogens from reaching the firefighter’s skin. The combination of these two layers are engineered to relieve heat stress by allowing air movement (breathability) while also preventing saturation of liquids through the garment.

Bunker gear has met its number one priority of providing an excellent source of protection. It has also drastically reduced the number of burn injuries to firefighters. Evidence of this fact can be seen by the results of the City of New York Fire Department (FDNY) pre- and post-bunker gear burn injury statistics. Prior to full implementation of bunker gear, 1586 burn injuries to its members were recorded in 1994. In 1996, after fully outfitting members with bunker gear, burn injuries plunged dramatically, dropping nearly 60% to 651 burn injuries.

Although burn injuries have declined, bunker gear still has some adverse effects on firefighters. Some of the problems associated with bunker gear are heat stress, muscle fatigue and dehydration. Fully encapsulated bunker gear offers excellent protection but at a price to the firefighter. Studies have shown that injury rates increase with fatigue levels, a phenomenon that usually occurs in the post-extinguishment phase (known as the overhaul stage in fire department operations).

Another negative aspect of bunker gear is that it is heavy and bulky. A firefighter requires a lot of mobility and flexibility while performing operations at fires, auto accidents and other rescue operations. A newer, lightweight bunker gear would offer firefighters greater mobility while also reducing muscle fatigue. Other advancements that would improve bunker gear would be:

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•increase the fabric’s and fiber’s ability to resist saturation of liquids

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•increase the overall strength of the fabrics and fibers in order to be more tear, rip, puncture and heat resistant

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•either treat the fabrics and fibers or create newer ones that can resist chemicals so that when exposed, the bunker gear does not disintegrate. Bunker gear has come a long way in its short career in the firefighting industry, but it can also be improved through new technology.

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The Protective Hood
rnMany fire service developments have been borrowed from other industries and occupations. One such item, the protective or Nomex hood, was borrowed from professional race car drivers. The hood has steadily contributed to the decline of burn injuries to the face, ears and neck of firefighters. There are many types of hoods commercially available made up of different percentages of materials such as a double 6 ounce or 8.5 ounce layer of knitted Nomex or PBI material. The FDNY currently uses a hood manufactured by Morning Pride, Inc., which is made up of a double knit fabric that is a blend of 20% PBI (polybenzimidazole, synthetic rayon fiber) and 80% Lenzing (flame-resistant, synthetic rayon fiber).

Although the protective hood adds to the encapsulation of the firefighter, it still affords the user superior protection and offers better breathability than bunker gear. The hood diminishes the firefighter’s ability to sense high heat conditions that would normally be felt on the ears and exposed skin; however, the time from sensation of pain to exiting a fire may only be seconds and with the use of a protective hood, major burn injuries can be avoided.

Protective Gloves
rnHand protection has also made great strides over the last 20 years. The old rubber and plastic gloves of the past kept hands dry but did little to provide protection from heat. Burn injuries to the hands were serious and painful. Many times, plastic gloves would melt into the hand, making burn care extremely painful and difficult.

Today’s gloves also incorporate a layered system (outer shell, moisture barrier and thermal liner) similar to bunker gear. The outer shell may be made of many different materials, such as leather, Nomex and pigskin. The gloves also feature thermal liners that may be constructed with self-extinguishing needlepunched fleece (SEF), a modacrylic liner that provides optimal thermal protection. The gloves feature liquid/moisture barriers to protect against water, fuels, chemicals and bloodborne pathogen contamination. Many of the moisture barriers are constructed with Cross-Tech, a barrier providing superior protection and breathability. A large number of gloves on the market are stitched with Kevlar thread for increased seam strength.

Although they are rather expensive—ranging in price between $25-$50 per pair—firefighting gloves are very durable and protective compared to gloves that were previously used.

As we approach the new millennium, firefighters are optimistic that bunker gear manufacturers will strive to produce new and even more lightweight products. These advancements will make the firefighter more mobile and enhance firefighting operations while decreasing the stressful effects bunker gear now has. Such developments will also reduce injuries and increase work performance and life expectancy. The new technological advancements on the horizon will surely assist firefighters in protecting society from the ravages of fire.

About the author: A fourth generation firefighter, Michael N. Ciampo has been employed by the City of New York Fire Department (FDNY) for nine years. He previously served with the District of Columbia Fire Department (DCFD) and holds a bachelors degree in Fire Science from John Jay College of Criminal Justice, New York, NY, and has been published in Fire Engineering, The Fireman’s Journal and Firefighter’s News.