Firefighting - Hazards Caused By Fire

Hazards Caused By Fire

One of the major hazards associated with firefighting operations is the toxic environment created by combusting materials. The four major hazards associated with these situations are as follows:

• Smoke, which is becoming increasingly dangerous due to the rise in synthetic household materials.
• Oxygen deficient atmosphere, 21% O₂ is normal, 17% O₂ is considered oxygen deficient.
• Elevated Temperatures
• Toxic atmospheres

To combat these potential effects, firefighters carry self-contained breathing apparatus (SCBA; an open-circuit positive pressure compressed air system) to prevent smoke inhalation. These are not oxygen tanks; they carry compressed air. SCBA usually hold 30 to 45 minutes of air, depending upon the size of the tank and the rate of consumption during strenuous activities.

Obvious risks are associated with the immense heat. Even without direct contact with the flames (direct flame impingement), conductive heat can create serious burns from a great distance. There are a number of comparably serious heat-related risks: burns from radiated heat, contact with a hot object, hot gases (e.g., air), steam and hot and/or toxic smoke. Firefighters are equipped with personal protective equipment (PPE) that includes fire-resistant clothing (Nomex or polybenzimidazole fiber (PBI)) and helmets that limit the transmission of heat towards the body. No PPE, however, can completely protect the user from the effects of all fire conditions.

Heat can make flammable liquid tanks violently explode, producing what is called a BLEVE (boiling liquid expanding vapor explosion). Some chemical products such as ammonium nitrate fertilizers can also explode. Explosions can cause physical trauma or potentially serious blast or shrapnel injuries.

Heat causes human flesh to burn as fuel, causing potentially severe medical problems. Depending upon the heat of the fire, burns can occur in a fraction of a second.

Additional risks of fire include the following:

• smoke can obscure vision, potentially causing a fall, disorientation, or becoming trapped in the fire;
• structural collapse.

According to a University News Bureau Life Sciences article reported by News Editor Sharita Forest and photographed by L. Brian Stauffer, from the website of the University of Illinois at Urbana-Champaign,: "Three hours of fighting a fire stiffens arteries and impairs cardiac function in firefighters, according to a new study by Bo Fernhall, a professor in the department of kinesiology and community health in the College of Applied Health Sciences, and Gavin Horn, director of research at the Illinois Fire Service Institute. The conditions (observed in healthy male firefighters) are "also apparently found in weightlifters and endurance athletes..."