Know your gear: Understanding the layers of protection
Here’s how turnout gear’s three layers work together to keep you safe
By Courtney Levin, FireRescue1 BrandFocus Staff
Of all the tools regularly used by firefighters, it can be argued that turnout gear is one of the most important. While there are a variety of ways to extinguish a fire, firefighters wouldn’t even be able to approach a blaze without wearing protective garments.
Turnout gear is much more than simply a pair of pants and a jacket. No matter what your turnout gear looks like, it’s critical that your gear is comfortable and works to keep you safe even under the most grueling conditions.
TODAY’S TURNOUT TECHNOLOGY
Just as the tools used to fight fires have advanced over the years, the technology used to fabricate turnout gear has also made leaps and bounds.
Today’s turnout gear is made using advanced fabrics and designed to help keep you cool and comfortable while ensuring you’re protected from the extreme heat of the fireground.
Here’s a closer look at the three layers that make up modern turnout gear and how each layer works to keep you safe:
1. OUTER SHELL
Acting as a firefighter’s first line of defense, the outer shell protects the body against sharp objects, high heat and direct flame. While it accounts for only about 21% of turnout gear’s overall thermal protection, the outer shell plays a large role in temperature regulation.
“The goal is to protect a firefighter from getting burned and to slow down the body core temperature from rising,” said Bart McCool, end-use business development at TenCate Protective Fabrics and 20-year veteran with Springfield Fire and Life Safety in Oregon. “Our blood being too hot remains the biggest risk to our cardiovascular system.”
Creating fabric that offers protection from direct flame without feeling suffocating seems like a tall order, but the team at TenCate Protective Fabrics found that using fibers that are extremely thermally stable makes all the difference.
“The fibers that we use in the outer shell are thermally stable, meaning that they’ll take a high amount of heat before they turn to dust and disappear,” said McCool. “None of them will ignite. They will basically turn to dust or carbon instead.”
TenCate Protective Fabrics’ newest outer shell material called Flex7 contains these resilient fibers. It features a smoother surface compared to other options and offers a broken-in feel to provide firefighters with greater mobility from the first time they don it.
2. MOISTURE BARRIER
High heat and direct flame aren’t the only concerns on the fireground, as keeping hazardous liquid materials away from a firefighter’s skin is just as important. This is where turnout gear’s second layer, the moisture barrier, comes into play.
“The purpose of this layer is to allow vapor to pass through it, but not liquid,” said McCool. “Picture a chain-link fence and imagine a water molecule is the size of a basketball. If you threw a basketball against a chain-link fence, it’s never going to go through. But a vapor molecule is the size of a golf ball, most of which will go through the fence.”
A great moisture barrier allows vapor molecules created by sweat pass to through, helping to keep firefighters as cool as possible. At the same time, any liquid the turnout gear encounters will be repelled due to the structure of the moisture barrier.
3. THERMAL LINER
Being able to wick away sweat when you’re facing extreme temperatures is an incredible feat but staying cool in this environment is just as impressive. Most of the thermal protection provided by turnout gear comes from the thermal liner, which is made of several smaller layers.
TenCate Protective Fabrics’ thermal liner material, Titanium Nano, works to pull sweat off the skin and move it through the moisture barrier without saturating the material. Designed with fibers that are 100 times smaller than what’s used in traditional thermal liners, Titanium Nano is a high-porosity material, meaning it both attracts and loses water very quickly.
The thermal liner is the only layer of turnout gear that is next to the skin, making it imperative that it wicks away moisture quickly. It’s able to achieve this through Coolderm technology which helps to promote body temperature regulation and keeps firefighters more comfortable.
“This thermal liner is 40% thinner than a traditional one,” said McCool, “which means a firefighter has way more mobility. This helps keep their body core temperature lower, and they use less oxygen while they’re working. What this provides is a far more efficient way of moving heat off the body and through the garment.”
Staying as cool as possible is key on many levels, as a first responder’s safety is constantly at stake.
“As a firefighter is working, the hotter they get or the wetter they are, their body’s absorbing heat from the outside that much more quickly,” said McCool. “This leads to them using more oxygen, they’re fatiguing faster, they’re becoming dehydrated, and their body core temperature is rising. This all affects your mental ability to make good decisions. It’s all connected.”
Firefighters know that when they put on their turnout gear, they’re going to be protected from extreme heat. What isn’t always guaranteed, though, is that they will be comfortable.
“There’s no test method to measure comfort. Breathability and how we move moisture around within and without the turnout is truly what creates comfort,” said McCool. “It may feel good to begin with, but as you’re working in it, if it doesn’t get rid of the moisture, suddenly that comfort is going to be overcome by the discomfort of being hot and sweaty.”
As technology advances to deliver better protection and comfort for firefighters, TenCate Protective Fabrics continues to keep safety at top of mind. Thanks to materials like Flex7 and Titanium Nano, firefighters can stay cool and focused on their task at hand even in the hottest environments.
Visit TenCate Protective Fabrics for more information.