firefighting

Firefighting or Fire fighting
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Firefighting is the act of extinguishing destructive fires. A firefighter fights these fires to prevent destruction of life, property and the environment. Firefighting is a highly technical profession which requires years of training and education in order to become proficient.



Firefighters' duties
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Firefighters' goals are to save life, property and the environment. A fire can rapidly spread and endanger many lives; however, with modern firefighting techniques, catastrophe is usually, but not always, avoided. To prevent fires from starting a firefighter's duties include public education and conducting fire inspections.

Because firefighters are often the first responders to people in critical conditions, firefighters provide many other valuable services to the community they serve, such as:

    * Emergency medical services, as emergency medical technicians or as licensed paramedics.
    * Hazardous materials mitigation (HAZMAT)
    * Heavy rescue
    * Search and rescue
    * Community disaster support

In addition, firefighters also service in specialized fields, such as:

    * Aircraft/airport rescue
    * Wildland fire suppression
    * Shipboard and military fire and rescue
    * Tactical paramedic support ("SWAT medics")

In the US, firefighters also serve the US Federal Emergency Management Agency (FEMA) as Urban Search And Rescue (USAR) team members.



Hazards caused by fire
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Firefighters arrive at the scene.
A burning building casts off clouds of smoke.

The primary risk to people in a fire is smoke inhalation (breathing in smoke; most of those killed in fires die from this, not from burns). The risks of smoke include:

    * suffocation due to the fire consuming or displacing all the oxygen from the air;
    * poisonous gases produced by the fire;
    * aspirating heated smoke that can burn the inside of the lungs.

As an example, plastics inside a car can generate 200,000 m3 of smoke at a rate of 20-30 m3/sec.[citation needed]. 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.

Obvious risks stem from the effects of heat. Even without contact with the flames (conduction), there are a number of comparably serious 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.

The heat can make pressurised gas cylinders and tanks 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 severe medical problems. Depending upon the heat of the fire, burns can occur in a fraction of a second. A first degree burn (on the skin surface) is extremely painful. A second degree burn is a burn into the skin, and can cause shock, infections, and dehydration and if left untreated often results in death. Second degree burns compromise nerve tissue and are not painful. Third degree burns leave muscles and internal organs exposed from completely destroyed skin. If the person survives the shock and exposure to germs, medical treatment is extremely difficult.

Additional risks of firefighting encompass the following:

    * vision can be obscured by the smoke: a person inside the building may not be able to see, can fall, or become disoriented and lost; becoming trapped and killed by the smoke or fire.
    * the building can collapse on its occupants.



Reconnaissance and reading the fire
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The first step of the operations is a reconnaissance to search for the origin of the fire (which may not be obvious for an indoor fire, especially when there are no witnesses), and spot the specific risks and the possible casualties. Any fire occurring outside may not require reconnaissance; on the other hand, a fire in a cellar or an underground car park with only a few centimeters of visibility may require a long reconnaissance to spot the seat of the fire.

The "reading" of the fire is the analysis by the firefighters of the forewarnings of a thermal accident (flashover, backdraft, smoke explosion), which is performed during the reconnaissance and the fire suppression maneuvers. The main signs are:

    * hot zones, which can be detected with a gloved hand, especially by touching a door before opening it;
    * the presence of soot on the windows, which usually means that combustion is incomplete and thus there is a lack of air
    * smoke goes in and out from the door frame, as if the fire breathes, which usually means a lack of air to support combustion;
    * spraying water on the ceiling with a short pulse of a diffused spray (e.g. cone with an opening angle of 60°) to test the heat of the smoke;
          o when the temperature is moderate, the water falls down in drops with a sound of rain;
          o when the temperature is high, it vaporizes with a hiss.

Ideally, part of reconnaissance is to consult an existing Preplan for the building. This would provide knowledge of existing structures, fire fighter hazards, and can include strategies and tactics.

Firefighting From Wikipedia
http://en.wikipedia.org/wiki/Firefighting