The self-contained breathing apparatus (SCBA) is the most advanced and intricate piece of personal protective equipment (PPE) that firefighters have to protect us in the environment of the fireground, which is toxic and not adequate to support life.
So how exactly does the SCBA protect firefighters? It protects the biggest and most easily compromised system in our body, the respiratory system. One breath from a toxic environment can kill us and we cannot even see what we are breathing in! All firefighters must wear and use their SCBA when they are exposed to any abnormal working environment. There is no excuse good enough to justify not wearing SCBA, although some firefighters still try to excuse themselves from doing so.
The SCBA is comprised of four parts: regulator, cylinder, back plate and harness, and face piece. No matter what brand of SCBA you are using, they all have these four basic components. Let’s look at each one to detail how well they will protect you when wearing it.
The face piece protects the user’s face and mouth (photo 1). The face piece doubles as a connection point for the regulator as well as impact protection for the face with the lens. With the current National Fire Protection Association (NFPA) 1981, Standard on Open-Circuit Self-Contained Breathing Apparatus (SCBA) for Emergency Services, the lens of the face piece had to be able to withstand higher heat temperatures (above 500°F) when exposed to them. The previous versions of the face pieces had a lower temperature rating (under 500°F) which made it the weakest link of the SCBA and PPE ensemble. The special coatings on the lens allows for more heat absorption and heat sink, which protects the user from the face piece failing too quickly when exposed to elevated temperatures. However, this can also be a detriment to the user because the heat absorbed is not able to dissipate quickly enough, causing the special coatings on the lens to break down. This is evident when inspecting the lens of the mask and noticing the marble-looking cracks and waves on the lens.
The regulator (photo 2) is where the closed system comes into play because it attaches to the face piece and provides a continuous flow of air to the user from the cylinder. The air flow in the regulator has been stepped down from the cylinder pressure of either 2,216 psi, 4,500, or 5,500 psi to about 100 psi or less. This is a breathable amount of pressure for the user and enough to expel unwanted environmental contaminants from entering the face piece from a broken seal. The regulator under the current NFPA 2013 edition must be CBRN compliant, meaning that it will still work and function when exposed to limited amounts of radiation, chemical, biological, and nuclear types of contamination.
The unique feature of the regulator is the emergency bypass valve–this is the firefighter’s protection feature when the regulator fails to work. The user can manually open the bypass valve and still have a free flow of air provided to them for the express purpose of getting out and staying alive. This function can be either opened fully with free-flowing air occurring or it can be opened and closed intermittently to allow for more air consumption time for getting out and staying alive.
The backplate and harness is where the electronic brains of the SCBA are usually located as well as the reducing block for the cylinder air to be processed and stepped down for the regulator (photo 3). Within the back plate will be the hoses for both high- and low-pressure systems running up and supplying the different aspects of the SCBA. These hoses will be buried within the backplate to protect them as much as possible from any entanglement hazards and cutting hazards. The previous versions of SCBA had these hoses exposed, which makes the firefighter vulnerable to potential snag and cutting hazards.
The straps of the SCBA are also designed to provide protection for the user. They are made from a Kevlar type of material for abrasion and cut resistance, which allows the user to not have to worry about the straps coming apart from the backplate when exposed to those hazards. Most straps will also have reflective material added to the front of them to provide more visibility at nighttime or when a light is shined upon them.
The working environment of the firefighter is harsh and the SCBA has been designed and constructed to meet those harsh demands so that it can function and provide a high level of safety and protection for the user. Make sure your firefighters are wearing it when they ought to be.
Mark van der Feyst has been in the fire service since 1999 and is a firefighter with the Fort Gratiot (MI) Fire Department. He is an international instructor teaching in Canada, the United States, and India, and at FDIC. He is also the lead author of Residential Fire Rescue (Fire Engineering Books & Video). He can be contacted at Mark@FireStarTraining.com.