Page 3Thursday 17th February, 2011 Feature The IslandBy Upali Jayathilaka

BBecause the onset of a fireand its deadly smoke canbe terribly rapid, toxic

gases and smoke produced byfires can prevent normal exitsfrom high raiser building in aslittle as 5 minutes to 8 minutes.

To survive a high riser hotelor apartment fire, it entirelydepends on early detection andsuppression.

Once the fire starts, it is toolate planning your escape. If theemergency evacuating plan isposted in your room/apartment,it will show your escape routeground floor out to the assemblyarea. Do not use an elevator dur-ing a fire. An elevator might stopat the floor where the fire is ormalfunction because of the fire.Always use the stairway. It is gen-erally not a good idea to jumpfrom a window unless you are onthe first floor with a rope ladder,you can be injured and it is likelythat you will not survive a jumphigher than the first floor.

Particularly toxic gases givenoff at a fire vary according tofour factors:

Nature of combustiblesRate of heatingTemperature of the evolved

gasesOxygen concentration

Some of the most commonlyfound gases in the fire scene iscarbon monoxide, immediatelydangerous to life/health.

However, before you arecaught in an emergency fire,panic is not as likely to set in andyour chances of escape are great-ly enhanced by practicing inter-nationally recognized guidelinesfrom fire professionals.

The evacuation drill proce-dure/ methods will help you tosurvive if a fire should breakoutin your hotel/apartment, whichis applicable anywhere in theworld, anytime you travel.

Remember, most fire depart-ment ladders do not reach abovethe sixth floor level.

Flashover…Several conditions or situa-

tions that occur during a fire itgrowth and development follows:Flames start rising upwards andseveral things happen within aburning compartment leading toa flashover (the simultaneousignition of all combustible mate-rial in an enclosed area).

The temperature is rapidlyincreasing, additional fuel pack-ages are being involved and thefuel packages in the compartmentare combustible giving off gasesbecause of pyrolysis and thegases ignite.

The heat released from a fullydeveloped room at flashover canbe on the oder of 10,000 kW ormore.

Occupants who have notescaped from the compartmentwhen the flashover occurs are notlikely to survive. Fire fighterswho find themselves in a com-partment during a flashover areat extreme risk even while wear-ing their personal protectiveequipment.

Thermal expansion…Thermal expansion is another

factor, for example, if a concreteor steel bar is heated, its volumewill increase slightly, this effect iscalled thermal expansion andusually too small to notice.

Nevertheless, unless space isleft for it, it can produce enoughforce to crack the concrete orbuckle the steel, resulting in acollapse.

History has shown that failureto recognize the potential dangerspresented by a particular type ofconstruction and the effects a firehas on it can lead to deadlyresults. The main purpose of myarticle is to acquaint the readerto meet fire related objectives,which can help to prevent person-

al tragedy and commercial loss.I hope that a fire will never

breakout in a hotel/apartmentwhere you are staying. However,you will sleep a lot easier in anyhotel/apartment if the companyhas taken necessary precautions,early (detection and suppression).

Portable fire extinguishers…Fire is a chemical reaction

known as combustion; it is fre-quently defined as rapid oxida-tion of combustible materialaccompanied by a release of ener-gy in the form f heat and light.

For many years, fire triangle(oxygen, fuel and heat) was usedto teach components of fire.While this simple example is use-ful, it is not technically correct.For combustion to occur, fourcomponents are necessary:

OxygenFuel Heat Self sustained chemical reaction

These components can begraphically described as firetetrahedron. Each component ofthe tetrahedron must be in placefor combustion to occur.

This concept is extremelyimportant to students of fire sup-pression, prevention, and investi-gation.

Fire extinguishment theoryFire is extinguished by limit-

ing or interrupting one or moreof the essential elements in thecombustion process (fire tetrahe-dron). A fire may be extinguishedby reducing its temperature,eliminating available fuel or oxy-gen, or stopping the self-sus-tained chemical reaction.

The portable fire extinguish-ers are one of the most commonfire protection appliances in usetoday, in found in fixed facilities.A portable fire extinguisher isexcellent to use on incipient fires.In many cases, a portable fireextinguisher can save lives andproperty by extinguishing a smallfire, or controlling it until the firedepartment arrives.

It is important to have knowl-edge about different types ofportable fire extinguishers.Knowledge where to place/installit and how to use it.

Fire extinguishers shall bemounted so that the top is not

more than 1.5 meters above thefloor.

Their location shall be con-spicuously marked or easily iden-tified: they must be easy to reachand remove and placed wherethey will not be damaged.

Stored pressure waterextinguisher

Stored pressure water extin-guisher also called air pressur-ized water extinguisher, are use-ful for small classed A fires andare often used for extinguishingconfined hot spots during overalloperations, as well as for extin-guishing chimney fires. Water isstored in a tank with either air ornitrogen. A pressure gauge locat-ed on the side of the valve assem-bly shows, when the gauge needlein operable range green. Whenthe operating handle is activat-ed/squeezed, the water is forcedup the sypon tube and outthrough the hose.

Water- red can be used forfires involving paper, wood, tex-tiles, solid materials, coal, someplastics, not to be used on firesinvolving; liquid, fat, electricity,oil. Dangerous; the water can con-duct the electricity back to you(electrocuting the user).

(AFFF) Aqueous film formingfoam fire extinguishers are suit-able for use on clan A and B firesthey are particularly useful incoating or suppressing vapors onsmall liquid fuel spills. AFFFextinguishers are different fromstored pressure water extinguish-es in two ways: AFFF extinguishertank contains a specified amountof AFFF (foam) concentrate mixedwith the water, and it has an airaspirating nozzle that aerates thefoam solution producing a betterquality foam than a standardextinguisher nozzle provides.

The water/AFFF solution isexpelled by compressed air ornitrogen stored in the tank withthe solution to prevent the distur-bance of the foam blanket. Whenapplying the foam, it should beallowed either to rain down ontothe fuel surface or deflect off anobject, when AFFF and water aremixed, the resulting finishedfoam floats on the surface of fuelsthat are higher than water. The

vapor seal created by the film ofwater extinguishes the flame andprevents re-ignition. However, thefoam is ineffective on flammableliquids that are water-soluble(polar solvents) such as alcoholand acetone. For large fires,mobile foam extinguishers ontrolleys could be utilized.

Alcohol foamAlcohol foams have been

developed for use on polar sol-vents, such as alcohol, lacquerthinner, acetone and ketones.Polar solvents are miscible inwater. This characteristic causesregular foams to break down rap-idly. The alcohol foams weredeveloped because regular foamsare very miscible in polar sol-vents, and tended to melt to theburning liquid without extin-guishing the fire. Additionally,regular hydrocarbon liquidsmixed with even small amountsof polar solvents tended todestroy the effectiveness of regu-lar foam products.

There is one type of protein-based alcohol foam. This foam isderived from regular proteinfoam mixed with heavy-metalsalts suspended in organic sol-vents. Protein-based solventsmust-to be affective-applied gen-tly to the burning surface, andmust be applied immediatelyafter eduction into the water.Protein-based alcohol foamswhen pumped through hose orpiping lose effectiveness, this lossis in proportion to the distance itis been pumped. For this reason,protein based alcohol foams aremixed into the water stream at ornear the application nozzle.

AFFF can be used for firesinvolving liquid, such as petrol,diesel, paint, thinner e.t.c. Paper,wood, textiles are not to be used onfires involving electricity andmetal.

Carbon Dioxide is storedunder its own pressure. A lique-fied compressed gas ready forrelease at anytime. The agent isdischarged through a plastic orrubber horn on the end of eithera short hose or tube. This gaseousdischarge is usually accompaniedby little dry ice crystals or carbondioxide “snow”, this snow sub-limes – change into a gaseous

form- shortly after dischargewhen released carbon dioxide dis-places available oxygen andsmothers the fire. Carbon dioxideproduces no vapor- suppressingfilm on the surface of the fuel;therefore, reignition of the fuel isalways a danger. Carbon dioxidefire extinguishers should not beused in confined spaces, as thecarbon dioxide gas will reducethe oxygen level to a point inca-pable of supporting human life.Carbon dioxide wheeled units aresimilar to the handled unitsexcept that they are considerablylarger; these units are intended tobe used only on clan B and Cfires. The hose usually more than15ft (5m) long can be used for fireinvolving energized electricalequipment are class C fires.Household appliances, comput-ers, transformers and overheadtransmission lines are examples.A non-conducting extinguishingagent such as dry chemicals orcarbon dioxide can sometimescontrol these fires.

The fastest extinguishmentprocedure is to first de-energizehigh voltage circuit and thenfight the fire appropriatelydepending on the fuel involved.

Dry chemical extinguisher

The term dry chemical and drypowders are often incorrectly usedinterchangeably. Dry chemicalagents are for use on class A-B-Cfires and/or class BC fires. Drypowder agents are for class D firesonly.

Dry chemical extinguishersare among the most commonportable fire extinguishers in usetoday including the domestictype., there are two basic types ofextinguishers (1) Regular B:C and(2) multipurpose ABC, the char-acteristics and operations of bothtypes are exactly the same.

The following are commonlyused dry chemicals:

Sodium bicarbonatePotassium bicarbonateUrea- potassium bicarbonatePotassium chlorideMono-ammonium phosphateDry chemicals agents are non-

toxic and generally consideredquite safe to use. However, the

cloud of chemicals my reducevisibility and create respiratoryproblems like any airborne par-ticulate.

Some dry chemicals are capa-ble with foam, but others willdegrade the foam blanket. Onclass A fires, the dischargeshould be directed whatever isburning in order to cover it withthe chemical.

Dry chemical wheel units aresimilar to hand held cartridge-operated extinguishers. However,on a larger scale they are ratedfor class A, B and C fires based onthe dry chemical in the unit.

The wheeled dry chemicalextinguisher, the extinguishingagent is kept in one tank, and thepressuring gas stored in a sepa-rate cylinder. Dry chemical storedpressure (nitrogen) mobile extin-guishers units are in existence.

Class D fires involve com-bustible materials such as alu-minum, magnesium, titanium,zirconium, sodium and potassi-um. These materials are particu-larly hazardous in their powderedform. Proper air born concentra-tions of metal dust can causepowerful explosions, given a sus-tainable ignition source.

The extremely high tempera-tures of some burning metalsmake water and other commonextinguishing agents ineffective.No single agent effectively con-trols fires in all combustible met-als. They are marked specificallyfor the metal fire they can extin-guish. All personal operations inthe burning area of the materialshould be in fuel protective equip-ment SCBA and those exposedshould be limited to only peoplenecessary to extinguish the fire.

Security solutionsIt is also important with

emerging needs for home/indus-try site surveillance and monitor-ing which ensures safety. Thesesystems are suitable for business-es, offices, warehouses e.t.c. cam-era with audio, security alarm toprevent intrusion attempt.

Halogen extinguishersUsing halongenated extin-

guishing agents are included inthe montreal protocol on sub-stances that deplete the ozonelayer. This international agree-ment requires a complete phaseout of the production of halogensby the year 2000. When a fireburns up in a confined space themake up of the atmosphere withinthe space, depending on the fuelchanges into several life threaten-ing situations. Some of the poison-ing gases released by a fire cancause unfortunate deaths. Onceyou lose the grip of controlling thefire using portable fire extinguish-ers, evacuate immediately by near-est exit closing doors/windows topredestinated assembly point, toprevent exposures to combinationof irritants and to vicants whosetoxicity cannot be predicted accu-rately. On arrival of fire depart-ment, give necessary attendance tocontrol the fire.

Effective and scientific firetraining can help prevent personaltragedy and commercial loss. Eventhe most basic knowledge of firerisk and the use of fire extinguish-ers can go a long way to preventstaff, customers and property.Concluding any emergency firerequires knowledge, ability, andskills.

How to survive highriser apartment fires

About the Author…The Author provides a

comprehensive fire safetytraining service throughoutthe industry. He is a fire crewchief, safety inspector, train-ing instructor worked forKing Fahd InternationalAirport KSA. At present, herenders his services as a tech-nical/marketing/admin/training manager at A and AEnterprises fire protectioncompany (pvt) ltd.

Flashover

Biyagama Fonterra Sri Lanka donated constructed a new building for Morawewa YayaSix Vidyalaya recently, in village that was once under the clutches of the LTTE. Pictureshows Fonterra Managing Director Achyut Reddy handing over the keys to the newbuilding to the Principal of the school, Ranjith Premalal.

Pic by W. D. Vithana, Delgoda Corr.

Nearly 100 senior citizens of Bopitiya, Pamunugama received donations from Dr.Viraj Peramuna JP, the President of the Lions club of the district.

Pic by S. K. J. Kurera, Pamunugama Corr.

SGS Lanka Private Ltd handed over a OHSAS 18001Quality Certificate to NoyonLanka Private Ltd. SGS Lanka’s Sumanasiri Batuvita (left) handing over the cerftifi-cate to Noyon Lanka’s CEO Murad Rajudin.

Pic by W. D. Vithana, Delgoda Corr.