By Mike McKenna
Last month, "Practical PPE" discussed the trade-off between the need for thermal protection and the need for dexterity. I received many interesting and often directly conflicting comments via e-mail. That is exactly what the NFPA 1971 Technical Committee is looking for. It is apparent that the fire service has very different ideas on what it needs and desires in a structural glove. In addition to your comments, there have been approximately 600 responses to the glove survey since we launched it earlier this year, including more than 250 from FireRescue1 readers. Please keep those survey responses coming.
It was encouraging to see that 97 percent of the respondents so far say they use NFPA certified structural gloves. The survey results indicate that what firefighters dislike most about their current structural gloves is the lack of "dexterity" followed by "bulky" design. The survey results also indicate that approximately 10 percent of firefighters liked "nothing" or "don't like" their gloves.
Dexterity and Grip
Last month I wrote that the most important feature of dexterity is grip. Grip allows the firefighter to use the surface of the palm of the glove to grasp, pinch, and grip tools and items. Grip is a function of many things including the length of the back of the glove, the fit of the glove, the pattern of the glove, proper sizing and the surface of the liner of the glove. Grip can be divided into two types: palm dexterity and finger dexterity.
Palm dexterity can be defined as the ability to grip something with the hand and fingers, which is the firefighter's ability to grab something such as a rope, a pike pole or an axe handle. This is a tough area for glove designers because some firefighters dislike gloves that fold or bunch in the palm when gripping items. Fold can lead to less surface area contact and less feel by the wearer.
Firefighters still need protection from hot objects and that protection comes from air space. Some manufacturers add texture to the surface to enhance the ability to grip things like ropes and axe handles to make up for losses in grip because of thermal protection.
Palm dexterity is affected by the flexibility of the palm material, the fit of the glove over the width of the palm, amount of leather on the surface, and the texture of the surface. In addition, the layers of materials used to protect the back of the hand from radiant heat have a dramatic effect on palm dexterity. Flexibility and dexterity are not the same. It is possible that a glove will feel very flexible, but not necessarily provide dexterity or thermal protection.
Several people commented to me after last month's column that fingertip dexterity was the most important feature of glove dexterity. Fingertip dexterity is the ability to use the fingers to pick up small items, or to feed rope through a Figure-8 or to change the channel on a portable radio. The survey responses suggest that fingertip dexterity is the number one deficiency in current structural gloves. Seventy two percent of the respondents to the survey stated that they had to remove their gloves to change radio channels.
All the items previously mentioned that affect palm dexterity also affect fingertip dexterity and the thermal layers are stuffed into a small space. However, there still has to be room for seams and liner attachment points.
Doffing and Donning
Designs that ease doffing and donning directly affect grip. The designs that have wide hand openings or are wider in the palm decrease the gripping power. In addition, some soft and fuzzy liner systems may actually take away some gripping power. If the hand is allowed to slide about and move within the glove, the gripping power is reduced.
Textured liner systems have better gripping power, but at the cost of ease of doffing and donning. There are gloves that provide great palm dexterity when donned, but getting the gloves donned can be difficult and perhaps impossible with wet hands.
Proper sizing is also a key element in the dexterity of the glove. It is important that the glove be the proper size for the individual. Proper sizing appears simple, but is complicated by ease of doffing and donning, finger length, thumb design and outer shell materials. It is common for firefighters to choose gloves that are too large because they are easier to doff and don.
However, sloppy fitting gloves are just as unsafe as gloves that are too small. When the gloves are too big, firefighters tend to take them off to do routine operations, leaving their hands exposed to injury. Firefighters take the gloves off because they cannot feel what they are doing.
Some firefighters choose gloves that are sized too small. Usually, this involves the firefighter not utilizing his wristlets, leaving that vulnerable interface area exposed. More importantly, the choice of gloves that are sized too small leaves the hands subject to burns because it compresses the thermal protection. Even with gloves that are sized too small, many firefighters are still taking their gloves off to complete many routine tasks.
When you take all of these issues into consideration, gloves sound really complicated. That is because gloves are very complicated and a key element of the ensemble. It is important that firefighters understand key areas of glove design so that they will understand the limitations to dexterity and tactility.
Lastly, firefighters also need to practice structural functions in their gloves as much as possible so that they are comfortable with the gloves. Remember, there is no protection at all if you take them off.