12PrinciplesofFireBehavioror roughly 1 in 1400 people will die by fire in the United States over yourlifetime.This fire fatalityfrequency is roughly10 times more than for auto-motivedeaths.As an alternativecheck on theseroughestimates,theNationalSafetyCouncil estimated for2007 that the chance of dying by fire inyourlifetime is 1in 1177, while dying in a motor vehicle is1 in 88.So with these current frequency estimates, you may have a neighborhoodfire (over roughly 200 households) about once a year, and you may know atleast one person who will diebyfire during your lifetime.These fire statis-tics relative to other threats topeople and propertydo not cry out for agreatconcernaboutfire.The causes of fire in dwellings for the United States are displayed inFigure1.2.The major causes are cooking and heating equipment.These aretechnological causes, except for the human role in cooking fires, and theyextend toareas ofelectricalappliances,lighting,and clothes washing anddrying appliances.Intentional is still significant,and could even be higher,asthisisnotaneasycall.The U.S. overall death rate due to all accidents since about 1900-2010 hassteadily dropped from about 80 per 100,000 of population to 40.8Figure 1.3shows the relative significance of fire with other accidental causes of death in2009.It clearlyshows that fireplaysa small rolecompared toother accidentalcauses.PlayingwithheatsourceExposure to other fireCandleClothes dryer/washerSmoking materialsElectrical and lightingIntentionalHeating equipmentCooking equipment01040502030Portion of fires (%)FIGURE1.2Causes of fire in homes in the United States 2005-2009. (From Accident Facts, National SafetyCouncil, Itasca, IL,1995.)
12 Principles of Fire Behavior or roughly 1 in 1400 people will die by fire in the United States over your lifetime. This fire fatality frequency is roughly 10 times more than for automotive deaths. As an alternative check on these rough estimates, the National Safety Council estimated for 2007 that the chance of dying by fire in your lifetime is 1 in 1177, while dying in a motor vehicle is 1 in 88. So with these current frequency estimates, you may have a neighborhood fire (over roughly 200 households) about once a year, and you may know at least one person who will die by fire during your lifetime. These fire statistics relative to other threats to people and property do not cry out for a great concern about fire. The causes of fire in dwellings for the United States are displayed in Figure 1.2. The major causes are cooking and heating equipment. These are technological causes, except for the human role in cooking fires, and they extend to areas of electrical appliances, lighting, and clothes washing and drying appliances. Intentional is still significant, and could even be higher, as this is not an easy call. The U.S. overall death rate due to all accidents since about 1900–2010 has steadily dropped from about 80 per 100,000 of population to 40.8 Figure 1.3 shows the relative significance of fire with other accidental causes of death in 2009. It clearly shows that fire plays a small role compared to other accidental causes. Playing with heat source Exposure to other fire Candle Clothes dryer/washer Smoking materials Electrical and lighting Intentional Heating equipment Cooking equipment Portion of fires (%) 0 10 20 30 40 50 FIGURE 1.2 Causes of fire in homes in the United States 2005–2009. (From Accident Facts, National Safety Council, Itasca, IL, 1995.)
13EvolutionofFireScienceOthersMechanical suffocationeaeaeosaoaeFireDrowningChokingFallsMotor vehiclePoisoning02468101214Death rate per100,000FIGURE1.3Death rate due to unintentional injuries 2009. (From Accident Facts, National Safety Council,Itasca, IL, 1995.1.5.2 United Statesand the WorldIt is of interest and curiosity to compare the U.S.fire statistics with the restof theworld.TheGeneva Association (www.genevaassociation.org)main-tains aprogram thattracks these statistics,and someadditional countrydatacame from Brushinsky.910 In Table 1.2, the death rate statistics are given asproduced in the first edition and amended to more recent times. China isupdated to 2004. It is difficult to draw generalities from the data, but therearesometrends.Cold weather countries tend to have generally high death rate from fire.China and Russia are at opposite ends, and one might wonder about thesedata. Statistical data for South America, the Mid-East,and Africa are not gen-erally available.It is a benefit to have these statistics,as they can set policyfor a country.Also, if we learn what underlies the statistics in one country,wemight benefit others. Social,culture, technology,climate,and preventionmeasuresallplaya roleinthesestatistics1.5.3U.S.FirePreventionInfrastructureFire events and statistics do move people to action. Throughout the twentiethcentury,mucheffort hasbeen put intothe prevention and protection fromfire.IntheUnited States,following theGreatFireof Baltimore(1904)and thefactthat thepropertyloss due to firewas then 10times that of Europe,anationalresearch program was initiated at the National Bureau of Standards (NBS)
Evolution of Fire Science 13 1.5.2 United States and the World It is of interest and curiosity to compare the U.S. fire statistics with the rest of the world. The Geneva Association (www.genevaassociation.org) maintains a program that tracks these statistics, and some additional country data came from Brushinsky.9,10 In Table 1.2, the death rate statistics are given as produced in the first edition and amended to more recent times. China is updated to 2004.11 It is difficult to draw generalities from the data, but there are some trends. Cold weather countries tend to have generally high death rate from fire. China and Russia are at opposite ends, and one might wonder about these data. Statistical data for South America, the Mid-East, and Africa are not generally available. It is a benefit to have these statistics, as they can set policy for a country. Also, if we learn what underlies the statistics in one country, we might benefit others. Social, culture, technology, climate, and prevention measures all play a role in these statistics. 1.5.3 U.S. Fire Prevention Infrastructure Fire events and statistics do move people to action. Throughout the twentieth century, much effort has been put into the prevention and protection from fire. In the United States, following the Great Fire of Baltimore (1904) and the fact that the property loss due to fire was then 10 times that of Europe, a national research program was initiated at the National Bureau of Standards (NBS) Others Mechanical suffocation Fire Drowning Choking Falls Motor vehicle Poisoning Death rate per 100,000 Categories of accidental death 02468 10 12 14 FIGURE 1.3 Death rate due to unintentional injuries 2009. (From Accident Facts, National Safety Council, Itasca, IL, 1995.)
14PrinciplesofFireBehaviorTABLE1.2AnnualFireDeathsper105PersonsCountry1992199420042008Country1992199420042008Russia10.6a1.260.98-France1.813.311.211.41HungaryCzech RepublicIndia2.20%Germany1.170.68-2.08Finland2.18Australia0.930.482.00aNew Zealand0.920.75Union So.Africa-1.951.210.860.58SpainUnited States1.641.280.80*1.56DenmarkPoland1.601.330.74NorwayAustria0.461.580.63Canada1.15Netherlands0.521.521.620.530.30JapanSwitzerland0.80United Kingdom1.49Italy0.300.461.470.1961.21China0.20aBelgium1.351.200.11SwedenSingaporeSource:World Fire Statistics Centre Bulletin 12 & 27,The Geneva Association,Geneva,Switzerland,1996/2011for1989-1992From Brushlinsky et al.9 for 1994.b.FromGuoandFu.11to investigate the consequences of fire on building construction materials.Steel and concrete buildings were not necessarily found to be"fireproof" TheNBSfireprogram in1913was established under SimonH.Ingbergwhowouldhead the Fire Resistance Section of the Heat Division for the next 40 years.In1914,duetoaCongressionalmandate,fundingandthechallengeofthecom-plexfireprobleminspiredmuchwork atNBS.NBShistory states"sobroadbecamethe scopeoftheinvestigationthat it soon involved almost everyoneofthe scientificand engineering laboratories of theBureau."12In addition,theNationalFireProtection Association(NFPA)was estab-lished in 1896 to provide a voluntary basis for technical information andstandards-recommended proceduresand-concerning firepractices-safety.In addition, in those early years, the Underwriters'Laboratory and theAmerican Society of Testing and Materials beganto contributestandard testmethodstoassessperformanceinfireconditions.Thisled tofireresistancetests thatenablethe measurementof theenduranceof structuralelements ofbuildingsand structuresinfire.Suchtests,conducted instandardfurnacesthroughout the industrialized world, help to ensure that structures do notcollapse because of fire. But all fires do not match the conditions of thestandard fire resistance furnace tests, and practices are not universal in theirattempts to match the testing results to actual anticipated fire conditions.More striking is the fact that "standard" furnaces do not always impart thesame fire heating conditions. Standard practices are not universal through-outtheworld,and theirapplication toreal fireconditions isfarfromperfect
14 Principles of Fire Behavior to investigate the consequences of fire on building construction materials. Steel and concrete buildings were not necessarily found to be “fireproof.” The NBS fire program in 1913 was established under Simon H. Ingberg who would head the Fire Resistance Section of the Heat Division for the next 40 years. In 1914, due to a Congressional mandate, funding and the challenge of the complex fire problem inspired much work at NBS. NBS history states “so broad became the scope of the investigation that it soon involved almost every one of the scientific and engineering laboratories of the Bureau.”12 In addition, the National Fire Protection Association (NFPA) was established in 1896 to provide a voluntary basis for technical information and standards—recommended procedures and practices—concerning fire safety. In addition, in those early years, the Underwriters’ Laboratory and the American Society of Testing and Materials began to contribute standard test methods to assess performance in fire conditions. This led to fire resistance tests that enable the measurement of the endurance of structural elements of buildings and structures in fire. Such tests, conducted in standard furnaces throughout the industrialized world, help to ensure that structures do not collapse because of fire. But all fires do not match the conditions of the standard fire resistance furnace tests, and practices are not universal in their attempts to match the testing results to actual anticipated fire conditions. More striking is the fact that “standard” furnaces do not always impart the same fire heating conditions. Standard practices are not universal throughout the world, and their application to real fire conditions is far from perfect. TABLE 1.2 Annual Fire Deaths per 105 Persons Country 1992–1994 2004–2008 Country 1992–1994 2004–2008 Russia 10.6a — France 1.26 0.98 Hungary 3.31 1.81 Czech Republic 1.21 1.41 India 2.20a — Germany 1.17 0.68 Finland 2.18 2.08 Australia 0.93 0.48 Union So. Africa 2.00a — New Zealand 0.92 0.75 United States 1.95 1.21 Spain 0.86 0.58 Denmark 1.64 1.28 Poland 0.80a 1.56 Norway 1.60 1.33 Austria 0.74 0.46 Canada 1.58 1.15 Netherlands 0.63 0.52 Japan 1.52 1.62 Switzerland 0.53 0.30 United Kingdom 1.49 0.80 Italy 0.30a 0.46 Belgium 1.47 1.21 China 0.20a 0.19b Sweden 1.35 1.20 Singapore — 0.11 Source: World Fire Statistics Centre Bulletin 12 & 27, The Geneva Association, Geneva, Switzerland, 1996/2011 for 1989–1992. a From Brushlinsky et al.9 for 1994. b From Guo and Fu.11
15Evolutionof FireScience1.5.4MotivationforImprovementIn theearly1970s,itwas acknowledged that the United States had thehighestannual death rate from fire of the world's industrialized nations.It had firedeaths peryearlisted at12,000.Once researchcommenced, thiswasquicklyreduced when it wasfoundthat an errorin compilingvehiclefiredeathshadbeen listed as 4000 instead of 400!Congress passed theFire Prevention and Control Act of 1974.Thisact structured the U.S.Fire Administration to enhance thepractice offirefighting,to improve education,to assess national fire statistics,and todevelop research. It focused research on the development of fire in build-ings: ignition, flame spread, smoke, and flashover (a sudden event in firegrowth that rapidly leads to full involvement of a room).The safety ofpeople rather than structures became the focus.This attitude of mandatedpublic safety,coupled with the threat of civil suits due to issues affectingfire safety,motivated the increasing use of innovativefire safety technolo-gies.These included residential smoke detectors, smoke control systems inlarge buildings, and the extension of sprinklers to public and residentialoccupancies. Indeed, many of these technologies have attributed the dropin annual U.S.fire deaths bymore than half of the 8000 in the early 1970s.Most of this drop is attributed to the widespread use of smoke detectors.Thisisremarkable.Changing technologies bring improvements in fire safety but can alsobring new risks. The high death rate due to fire in the United States and inother industrialized nations may be associated with the changing technolo-gies with which we live. Change brings risks, some unexpected. For exam-ple, in the 1970s, lightweight cellular plastics (such as foam polyurethaneand polystyrene)were seeing newinnovative applications,buttheirfirehazards were not fully appreciated. Standard tests suggested no problems,but accident scenarios showed a dramatically fast rate of fire spread. Theseincidents brought standard flammability tests into question.The FederalTrade Commission (FTC)enjoined the plasticindustryto take correctiveaction.TheProductResearchCommittee(PRC)was establishedbyindustryin1974 toexamine this issuefor cellularplastics asaresult of aconsent orderbetweentheFTCandtheindustry.131.5.5FlammabilityTestsAlthough the PRC group gained much insight into the issue of foamplastic flammability,it remains unresolved today.To mitigate concern,today lightweight cellular plastics are generally required to be covered bywallboard inbuildingconstructionapplications evenaftertheypassthetestrequirements for flammability. Confidence in their flammability ratings bystandard tests is low.But this issue of product flammabilityis not uniquetocellular plastics; it is widespread
Evolution of Fire Science 15 1.5.4 Motivation for Improvement In the early 1970s, it was acknowledged that the United States had the highest annual death rate from fire of the world’s industrialized nations. It had fire deaths per year listed at 12,000. Once research commenced, this was quickly reduced when it was found that an error in compiling vehicle fire deaths had been listed as 4000 instead of 400! Congress passed the Fire Prevention and Control Act of 1974. This act structured the U.S. Fire Administration to enhance the practice of firefighting, to improve education, to assess national fire statistics, and to develop research. It focused research on the development of fire in buildings: ignition, flame spread, smoke, and flashover (a sudden event in fire growth that rapidly leads to full involvement of a room). The safety of people rather than structures became the focus. This attitude of mandated public safety, coupled with the threat of civil suits due to issues affecting fire safety, motivated the increasing use of innovative fire safety technologies. These included residential smoke detectors, smoke control systems in large buildings, and the extension of sprinklers to public and residential occupancies. Indeed, many of these technologies have attributed the drop in annual U.S. fire deaths by more than half of the 8000 in the early 1970s. Most of this drop is attributed to the widespread use of smoke detectors. This is remarkable. Changing technologies bring improvements in fire safety but can also bring new risks. The high death rate due to fire in the United States and in other industrialized nations may be associated with the changing technologies with which we live. Change brings risks, some unexpected. For example, in the 1970s, lightweight cellular plastics (such as foam polyurethane and polystyrene) were seeing new innovative applications, but their fire hazards were not fully appreciated. Standard tests suggested no problems, but accident scenarios showed a dramatically fast rate of fire spread. These incidents brought standard flammability tests into question. The Federal Trade Commission (FTC) enjoined the plastic industry to take corrective action. The Product Research Committee (PRC) was established by industry in 1974 to examine this issue for cellular plastics as a result of a consent order between the FTC and the industry.13 1.5.5 Flammability Tests Although the PRC group gained much insight into the issue of foam plastic flammability, it remains unresolved today. To mitigate concern, today lightweight cellular plastics are generally required to be covered by wallboard in building construction applications even after they pass the test requirements for flammability. Confidence in their flammability ratings by standard tests is low. But this issue of product flammability is not unique to cellular plastics; it is widespread
16PrinciplesofFireBehaviorThe disparity amongflammabilitytests forconstruction materials isillustrated in Figure1.4 for six national European tests in the ranking of24materials.ProfessorHowardEmmonspublicized this chartafterhedis-covered these data in Europe during a world tour to reviewthe status offire science.l Perfect correlation among all of the six tests should producethe sameranking for the 24 materials; this would be a 45°straight-linecor-relation.For example, the number 6 material should be ranked as 6 byallthetestsforaperfectcorrelationofflammability.Thetestsdecidedlydonotcorrelate!Eachcountry'stestgivesadifferentmeasureofflammabilityforthesamematerial2422201816Mtsa1210426641012141618202224VarietiesofwallboardGermanyFranceOBelgiumNetherlandsDenmarkEnglandFIGURE1.4Disparities among fire tests-rankings of 24 materials by six national flammability testmethods. (From Emmons,H.W., Fire Res. Abstr. Reu., 10(2), 133, 1968.)
16 Principles of Fire Behavior The disparity among flammability tests for construction materials is illustrated in Figure 1.4 for six national European tests in the ranking of 24 materials. Professor Howard Emmons publicized this chart after he discovered these data in Europe during a world tour to review the status of fire science.14 Perfect correlation among all of the six tests should produce the same ranking for the 24 materials; this would be a 45° straight-line correlation. For example, the number 6 material should be ranked as 6 by all the tests for a perfect correlation of flammability. The tests decidedly do not correlate! Each country’s test gives a different measure of flammability for the same material. 2 10 0 2 4 6 8 10 12 Test rating14 16 18 20 22 24 4 6 8 12 14 16 18 20 22 24 Varieties of wallboard Denmark England Netherlands Germany France Belgium FIGURE 1.4 Disparities among fire tests—rankings of 24 materials by six national flammability test methods. (From Emmons, H.W., Fire Res. Abstr. Rev., 10(2), 133, 1968.)