Firefighting

Fire fighting is the act of carrying out procedures to extinguish an unwanted fire more...

In all but the most trivial cases, knowledge and expertise are necessary for successful and safe fire-fighting.

Historically, fire scientists created a graphical representation detailing the three elements fire needs to start (fire triangle). In recent years, one more point has been added, creating the fire tetrahedron.

The three elements needed for the initial start of combustion (a form of oxidation; see the article on combustion) are:

• combustible matter (fuel): paper, wood, gasoline, oil, gas, etc.;
• a combustive agent, i.e. an oxidant, usually the oxygen of the air;
• activation energy: heat, spark (electricity), etc.
• The fourth element is a chemical chain reaction needed to sustain fire.

To extinguish a fire, it is necessary to remove either the fuel or the combustive agent (once started, the fire requires no further activation). Once the fire has been suppressed, it is necessary to reduce the temperature of the surrounding objects so the fire does not start again.

Risks of a fire

The obvious risk is heat. Even without contact with the flames, there are a number of comparably serious risks: burns from infrared radiation (radiated heat, like a domestic grill), contact with a hot object, hot gases (e.g., air), steam produced by spraying, and hot or toxic smoke. Firefighters are normally equipped with personal protective equipment (PPE) that includes fire-resistant clothing and helmets that slow down the diffusion of the heat towards the skin.

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