Iycee Charles de Gaulle Summary Fire fighting foams Essay

Fire fighting foams Essay

Fire fighting foams

            Fire is as ancient as pre-civilization when cavemen built fires to keep warm and to grill their food.  Fire has its many uses and men certainly can not live without it.  While fire has its acknowledge value, it can be destructive also.  Fire can do much damage to life, property and the environment.  It is only recently that the environment was given equal and significant focus on.

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            There are small fires and there are big fires and damage can range from slight to massive.  Fires may happen to a kitchen, an entire house, a block of buildings, industrial plants, ships, aircrafts, refineries, airports and forests.  Fire fighters do everything they can to put out fires.  The problem does not end when the fire has been put under control.  Loss of lives, damage to property and environmental disaster result long after the fires has been contained.

            Fire has three basic elements, namely:   heat, oxygen and fuel.  Only if all three of these basic elements are present will there be fire.  Without any one of them, fire would become impossible.    Take the case of the caveman.  To build a fire all he did was to rub two stones against each other to produce friction that would ignite dried twigs and leaves, in open air.  Heat is the friction produced, fuel is the twigs and leaves and the air around is oxygen.  Basically, this is what the fire fighter needs to know.  Removing one of the elements is in effect putting out a fire.

            Most common fire fighting means is the use of water.  Dousing fire with water stops the fire as water cools down the temperature.  Simply, if there is no heat, there will be no fire.  Water, however, may not be enough to contain large fires like forest fires.  A forest of pine trees would provide great source of fuel as such a vast source of ignition.  It may be very difficult to control by water alone.

            Over the years, additives have been used in combination with water for fire fighting, such as foam solutions.  They were first used in 1928.  They act as shield over the flames, first as coolant and then as block from contact with oxygen.  For the past 72 years all kinds of fire fighting foams were developed.  All were effective and serve the purpose of fire fighting.  As people have been more conscious of the environment and its protection, probe and continuous watch over elements that may be harmful to nature has been done.

            It became as much the concern of the fire fighter not only to extinguish fires but also to ensure the chemicals used in their extinguishing solutions do not contaminate groundwater and do environmental harm in the process.  “They destroy the microorganisms in the soil, preventing the decomposition of organic matter, a crucial step in maintaining a balanced ecosystem.”  (Quesada, 2001.)

            Sometimes, nature helps.  Rain can eventually do its own cleaning and dispersing.  When the concentration is too high, something more has to be done.  Manual cleaning has to be done with the fire fighting debris like shoveling, scooping and suctioning.

            Fire fighting foams contain surfactants, solvents, stabilizers and corrosion inhibitors.  They are classified according to expansion rate.  The low-expansion foams are used for large areas and burning spills.  They have low viscosity and move rapidly to contain fire in expansive areas.   For enclosed spaces fires the foam to use is the high-expansion foams.  There are foams that are suited to particular types of fires.  Class A foams are used in Class A fires.  This was developed in the 1980s initially for fighting wildfires.  Class B foams on the other hand are used to control fires caused by flammable liquids.  There are other types of foams like the alcohol-resistant for use in fires of fuels with oxygenates, liquid based fires and fires with solvents.  Class B foams have two sub-types which is the synthetic foams and the other is the AFFF or aqueous film-forming foams.  Synthetic foams have synthetic surfactants. They give better flow and faster control of fire but they do not give adequate protection after the fire has been contained.  AFFF foams are water-based and are resistant to action of alcohols.  Protein foams contain protein-foaming agents.  They may flow or spread slower and the blanket it forms is more resistant to heat and is longer-lasting.  Each type of foam is best suited to particular type of fire.  Using the wrong foam for the wrong class fire may have adverse results.

            In the Australian Bushfire Conference in 1999, focus was on the effects of firefighting foams and retardants on ecology.  While they noted that the use of retardants and foams are gaining popular use, limited data is available to ascertain their effect on the ecosystems.  Studies on the effects of retardants and foams on vegetation were presented.  There had been a few noted toxic effects of certain retardants on certain plants, fish, and birds.  They range from “shoot and leaf damage, stupor and lack of coordination but no noted mortality, increase in biomass and decrease of ability to obtain oxygen.” (Adams and Simmons, 1999)

            The UK-based FETA supports the concern over the use of Telomar foams as the being most effective in fighting large scale fires, yet it has certain environment risks.

            In the United States there is now Green Foams in the market.  They are the most environment friendly foams.  They contain live bacteria.  These bacteria are supposed to eat up the remaining fuel after the flames have been contained.

            Firefighters and environmentalists are striking a balance between using the best and the most effective firefighting foams and firefighting foams with the most bio-friendly chemicals.  The most appropriate of firefighting foams have fast containment capabilities as against the less effective firefighting techniques of non-foams where the damage would be greater because of slow suppression of fire.

            Some use the proactive approach on the issue of fire fighting by educating people on how to protect themselves and their communities from fires, while fire fighting foams continue to develop to leave the ecosystems untouched after suppression of fires.

Sources:

Zelaya-Quesada, Myrna.  (2001, April). Chemical Foams in the Line of Fire: ChemMatters.

    American Chemical Society.  Retrieved November 17, 2006 from

    <http://www.chemistry.org/portal/a/c/s/l/feature_ent.html?>

Adams, Robyn and Simmons, Dianne.  (1999, July).  Ecological Effects of Fire Fighting

    Foams and Retardants:  Conference Proceedings.  Australian Bushfire Conference.

    Retrieved November 17, 2006 from

    <http://www.csu.edu.au/special/bushfire99/adams/index.htm>

Fire Retardant Foam.  (2006, October 20).  Wikipedia.  Retrieved November 17, 2006 from

    <http://en.wikipedia.org/wiki/Fire_retardant_foam>

FETA Focuses on Topical Issues.  (n.d.).  News Feature Articles.

    Retrieved November 17, 2006 from

   <http://www.feta.or.uk/News/Feature%20Articles/topicalissues.htm>