Reporting of Fire Incidents in Heavy Timber Structures

Transcription

1 United States Department of Agriculture Forest Service Forest Products Laboratory Research Paper FPL 464 Reporting of Fire Incidents in Heavy Timber Structures Robert H. White

2 Abstract This investigation of fire in heavy timber construction is based solely on the data files of the National Fire Incidents Reporting System (NFIRS) of the Federal Emergency Management Agency. Buildings of heavy timber construction usually consist of interior columns, beams, and floors of wood and exterior walls of noncombustible construction. About half of the reported involved one of two types of fixed property use which present different types of fire problems: either one- and two-family dwellings or agricultural products storage structures (barns and stables). Both types of structure are likely not to meet the-building code definition of heavy timber or type IV construction, although they have heavy timber members. Our main conclusions are (a) there is a need to clarify and improve the coding both for type of construction and for extent of fire damage; (b) solid fuel heating systems are the major cause of fires in the residential heavy timber structures; (c) fires of incendiary or suspicious origin are a significant portion of the agricultural product storage fires. Keywords: Fire, heavy timber, dwellings, barns, stables. December 1985 White, Robert H. Reporting of fire in heavy timber structures. Res. Pap. FPL 464. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory; p. A limited number of free copies of this publication are available to the public from the Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI Laboratory publications are sent to over 1, libraries in the United States and elsewhere. The Laboratory is maintained in cooperation with the University of Wisconsin.

3 Reporting of Fire Incidents in Heavy Timber Structures Robert H. White, Research Forest Products Technologist, Forest Products Laboratory, Madison, WI Introduction Methodology Heavy timber construction is widely recognized as having a high level of firesafety, based on its performance in actual fires. The objective of the present study was to gain insight into the firesafety performance of buildings of heavy timber construction, as recorded in-the files of the National Fire Incidents Reporting System (NFIRS), and the frequency of fires in such buildings. These buildings usually consist of interior columns, beams, and floors of wood and exterior walls of noncombustible construction. As will appear in this report, attainment of our objective was not possible. National Fire Incidents Reporting System The investigation was based solely on data obtained from the files of NFIRS. The NFIRS is the collection of fire, fire casualty data, and other fire department responses established by the Federal Emergency Management Agency (FEMA) (Kraft and Collins 196). The coded fire incident and casualty reports are voluntarily filled out by local fire departments and compiled at the state and federal levels. For each fire, the incident reports consist of 59 items, including data on the building characteristics; the location, ignition and spread of the fire; the extent of flame, smoke, and water damage; the amount of dollar loss; and the number of casualties. Included in the building characteristics is the type of construction (fire resistive, heavy timber, etc.). For this study, we selected those that involved structures classified as heavy timber construction. These we have analyzed as they relate to the NFIRS codings for selected items including fixed property use, type of structure, and extent of damage. The coding for the different items is found in the NFIRS Handbook (National Fire Data-Center 1978b) and is generally consistent with the 1976 edition of the National Fire Protection Association (NFPA) No. 91, Uniform Coding for Fire Protection (NFPA 1976). We studied data files for the 5 years 1977 to During this period, were reported from fire departments in 9, 16, 23, 32, and 33 states, respectively, and in 1981 also from the District of Columbia. Incidents include structure fires, vehicle fires, and outdoor fires. The total number of ranged from 43, in 1977 to 68, in For each of the years, about 2, of the were from California. California uses a different coding for type of construction which does not permit the selection of heavy timber structures. As a result, California data were excluded from this study. The NFIRS data have previously been used to examine the fire experience of building material distributors and dealers (Penoyar 198) and the solid wood products industry (Penoyar 1981). The data have also been used to study mobile home, wood roof, and garden apartment fires (Glowinski 198). Annual reports based on the data have been published (Federal Emergency Management Agency 1982 and later, National Fire Data Center 1978a). The NFIRS data and software are available from the National Technical Information Service (NTIS) Computer Products Division.

4 Data Selection We selected records from the master files referring to one type of situation (structure fires (11) 1 ) and one type of construction (heavy timber (2)). Structure fires include any fires inside a building or structure, whether or not the fire causes structural damage to the building or is out on arrival of firefighters. Heavy timber is described as a typical mill-constructed building in which the load-bearing walls or columns are masonry or heavy timber, and all exposed wood members have a minimum dimension of 2 inches (National Fire Data Center 1978b). The three model codes include heavy timber in the following categories: Basic Building Code type 3A, Standard Building Code type III, and Uniform Building Code type III (HT). Construction types not selected are: fire resistive (1) protected noncombustible or limited combustible (3) unprotected noncombustible or limited combustible (4) protected ordinary (5), unprotected ordinary (6) protected wood frame (7), unprotected wood frame (8) not classified above (9) and undetermined or not reported (). These categories are based on the editions of the model codes current in Different names and categories are used in the current editions of the codes and the 1981 edition of NFPA 91. An exposure fire occurs as a result of another fire. When exposure fires occur, separate incident reports are made out for each exposure. In the analysis of the data, we treated each exposure as a separate occurrence. Thus, exposure fires may possibly have resulted in our inclusion of multiple records for the same incident. For selected items, including fixed property use, structure type, and extent of damage, we calculated the number of occurrences, total number of injuries, total number of deaths, and total dollar loss for each of the 5 years (table 1). 1 Number in parenthesis is the numerical code for the item (e.g., the type of situation found or type of construction) given in the NFIRS incident report. Dollar loss is recorded in two ways: as an estimated dollar loss and/or by property damage classification. There are 1 classes of property damage: $1 to $99 (1) $1 to $999 (2), $1, to $9,999 (3), $1, to $24,999 (4) $25, to $49,999 (5) $5, to $249,999 (6). $25, to $999,999 (7) $1 million or more (8) no dollar loss (9) and undetermined or not reported (). Our summary of dollar loss was based on the estimated dollar loss. When no estimated dollar loss was given, an average value based on the property damage classification was used instead, except for class (8) ($1 M or more) for which $1 million was used. In the statistical analysis of the data, we considered the data for each year as an independent data set. We calculated the rate of occurrence for each division of the item, coded through 9, omitting class () ( undetermined or not reported ) from the denominator (table 2). This assumes that in class () were distributed proportionately over the other classes. The omission was made to minimize the effect of variations in class () on the percentages reported for the different years. We calculated the means and standard of the means and evaluated the significance of differences in the means. The percentage of all that were undetermined or not reported was also calculated. Table 1. Overall summary of all fire Total Number per 1, Yearly total Mean 1 Standard 1 Incidents (records) ,248 1,331 1,84 2,31 7,265 Exposures Fire service injuries Other injuries Fire service deaths Other deaths Dollar loss ($1,,'s) Mean and standard of the five yearly data sets. 2 Excludes all of Michigan data since type of situation found was coded "Fire explosion; insufficient information available to classify further" (1). Table 2. Major divisions of fixed property use Rank Fixed Property Use Total number of Mean Percentage of 1 Standard 1 Residential property (4) 2 2, storage property (8) 2, Manufacturing property (7) Special property (9) Store, office property (5) Public assembly property (1) Basic industry, utility, defense property (6) Educational property (2) lnstitutional property (3) Undetermined or not reported () Values for ranked items are percentages of all for which fixed property use was determined: and for class (), unranked, are Percentages of all. Mean and standard values are based on the data for each of the 5 years. 2 Numbers in parentheses are NFIRS codings for categories of fixed property use. 2

5 Results and Discussion A total of 7,265 of the selected records, coded as heavy timber (type of construction 2), were obtained from the NFIRS 1977 to 1981 data files. Table 1 gives an overall summary of the data. The number of increased with the years, as more states participated in NFIRS. Of these 7,265 records, 3 percent were for exposure fires. Of the 715 injuries, 72 percent were suffered by firefighters. In contrast, 89 percent of the 44 fatalities were civilians or other emergency personnel. On the average, there were 12 injuries and 6 deaths per 1,. The total dollar loss reported for the 5-year period was $133 million. On the average, each fire resulted in an $18, loss; 27 percent of the fires involved dollar losses less than $1,, and about 1 percent resulted in dollar losses in excess of $25,. The reported dollar loss is the total loss of contents and structure in terms of the cost of replacement in like kind and quality. The loss does not include indirect monetary costs such as medical costs and lost time at work nor the many nonmonetary costs of a fire. Indirect costs of medical care and temporary shelter can be substantial in residential fires (Munson and Ohls 1979). Our figures are based only on reported. The per incident value is generally lower when estimates for unreported are included. Fixed Property Use There are nine categories, called major divisions, of fixed property use (table 2). Percentages reported in tables 2 and 3 do not include in which the fixed property use was undetermined or not reported. Percentages are the average of the percentages for each of the 5 years. We found two major divisions, together, accounted for 69 percent of the reported : residential property (4) and storage property (8). Manufacturing property (7) accounted for 9 percent of, store or office property (5), and special property (9) for about 5 percent each. Special properties are mainly outdoor properties such as construction, bridges, outbuildings, and railroad properties. Residential property and storage property account for 68 percent of injuries, about the same proportion as for. Fires in residential property accounted for 65 percent and those on storage property for only 6 percent of the fatalities. In contrast, storage property accounted for 41 percent and residential property for about 18 percent of the total dollar loss. The nine major divisions for fixed property use are subdivided into divisions. These divisions are then subdivided (table 3). Over 5 percent of the were either one- and two-family dwellings (41) or agricultural products storage (81). Eighty-eight percent of the agricultural products storage (81) were barns and stables (815). No other division had more than 5 percent of the. Fires in agricultural products storage and one- and two-family dwellings are discussed in more detail in the appendix. Type of Structure Table 3. Divisions of fixed property use reported most frequently Rank Fixed Property use of The NFIRS classification by structure type is coded from (1) to (9). In 97 percent of the, the structure type was a building (1 or 2). In 12 percent of the buildings, there were two or more fixed property uses (2). The heavy timber structure was an open structure (3) in 2 percent of the. Open structures include roofs with no walls, bridges, and trestles. The remaining 1 percent of the include air-supported structures (4), tents (5), open platforms (6), and underground structures (7). The construction method for the structure in 97 percent of the was site built (1). In 2 percent of the, it was a factory-built, site-assembled structure (2). The remaining 1 percent include factory-built modular structures (3), factory-built mobile structures (4), and those not classified above (9). Percentage of Number 1 Mean Standard 1 One- and two-family dwelling 2, (41) 2 2 Agricultural products storage 1, (81) 3 Apartments, tenements, flats (42) 4 Construction, unoccupied property (91) 5 Wood, furniture, paper printing, manufacturing (75) 6 Vehicle storage (88) Agriculture (65) Metal, metal products manufacturing (77) 9 Eating, drinking places (16) General item storage (89) Special structures (92) Care of the sick, injured (33) Unclassified () Values for ranked items are percentages of all for which fixed property use was determined; and for class (), unranked, are percentages of all. Mean and standard values are based on the data for each of the 5 years. 2 Numbers in parentheses are NFIRS codings for subcategories of fixed property use. 3

6 Classification of Heavy Timber Construction The large number of heavy timber fires in agricultural products storage and one- and two-family dwellings raises a question as to what are being classified as heavy timber structures. As mentioned above, the NFIRS Handbook (National Fire Data Center 1978b) describes heavy timber as a typical mill-constructed-building in which the load-bearing walls or columns are masonry or heavy timber. and all exposed wood members have a minimum dimension of 2 inches. Using this definition, many people classify such structures as log cabins and pole frame buildings as heavy timber. Most of the agricultural products storage buildings were barns and stables. Poles in farm service building construction amounted to approximately 72 million linear feet in 1975 (Reid and Baumgartner. 1977). Based on a 1968 to 197 survey, about one-third of all farm service buildings were of pole construction (Reid and Baumgartner 1977). Pole structures are also used for multifamily and single-family residences. It is estimated that 3, to 4, log homes were built in 1983 (Anonymous 1984). The definition of heavy timber construction in NFPA 22 (NFPA 1979) is somewhat narrower. Type IV construction (formerly heavy timber) is defined as:... that type in which exterior and interior walls and structural members which are portions of such walls are of approved noncombustible or limited-combustible materials. Other interior structural members including columns, beams, arches, floors, and roofs are of solid or laminated wood without concealed spaces and comply the provisions of through In addition, structural members have fire resistance ratings not less than those set forth in table Table 3 of NFPA 22 lists 1 and 2 hours fire resistance requirements for the interior and exterior bearing walls. Provisions through give the minimum dimensions required for the structural wood members. Log homes and pole frame construction would not satisfy this definition of heavy timber construction. We consider it highly unlikely that there are sufficient agricultural products storage and one- and two-family dwelling structures meeting the NFPA 22 definition to result in the large proportion of fires recorded for these two fixed property uses. The data for the different states suggest that different definitions for heavy timber construction are being used in the various States participating in the NFIRS (table 4). For example, both Minnesota and Oregon reported about 8, in the 5-year period. In Minnesota,.49 percent of the were classified as heavy timber structure fires. Of these 397 heavy timber structure fires, 38 percent were either one- and twofamily dwellings or agricultural products storage. In Oregon,.14 percent of the were heavy timber structure fires. None of the Oregon fires were one- and twofamily dwellings or agricultural products storage facilities. Demographic differences between Minnesota and Oregon are unlikely to account for the differences in reported heavy timber structure fires. Other States with 11 percent or less of heavy timber fires in one- and twofamily dwellings or agricultural products storage include Colorado, Hawaii, Massachusetts, Washington, and Wisconsin. States in which heavy timber structure fires in one- and twofamily dwellings or agricultural products exceeded 58 percent included Maryland, Michigan, Montana, Ohio, North Carolina, Texas, and Tennessee. Clarification of the criteria for classifying a structure as heavy timber is needed to improve uniformity in future fire records. One possibility is to add subdivisions to construction-type coding. For heavy timber, the sub- divisions needed include type IV construction, pole structures, log cabins, and other structures with large wood members. Other Considerations Annual Variations The mean results presented in this paper assume that the data for each year represented the same population. Because States were added in the-later years and other things changed over time, this assumption is not completely accurate. In 1977, Ohio accounted for 64 percent of the heavy timber. By 1981, the contribution from Ohio had dropped to 2 percent, and the States of Michigan, Illinois, Minnesota, New York, Ohio, and Washington together accounted for 63 percent of the. Small standard s in the means indicate that either the changes did not affect the results or that the changes tended to balance out. Large standard s may represent true large random variations, trends in the results, or simply differences in the data base for the 5 years. Generally, the standard s were large relative to the mean only when the number of was small. Extent of Damage The classification of the extent of flame damage consists of 1 items: (1) confined to the object of origin, (2) confined to part of room or area of origin, (3) confined to the room of origin, (4) confined to fire-rated compartment of origin, (5) confined to floor of origin, (6) confined to structure of origin, (7) extended beyond structure of origin, (8) not a structure fire, (9) no damage of this type, and (1) undetermined or not reported. In 58 percent of the involving one- and twofamily dwellings, the flame damage was confined to the room of origin (1,2,3), in 21 percent it was confined to structure of origin (6), in 13 percent to floor of origin (5), and in 3 percent to fire-rated compartment of origin (4). 4

7 Table 4. Numbers of heavy timber by state Number of heavy timber Dwelling or State 1 Years Per 1, One- and Agricultural agriculturai reporting Total total two-family- Products products dwelling Storage storage 2 reported Pct AK AZ CO CT DC DE GA HI IA IL KS LA MA MD ME Ml , MN MO MT NC NE NH NY OH , OR RI SD 1978, TN TX UT VA WA WI WV WY All , ,361 1, Including the District of Columbia (DC). States reporting no heavy timber included AR, ID, and CA. California uses a different coding that does not permit the selection of heavy timber. 2 Percentages of heavy timber for either one- and two-family dwellings or agricultural products storage. Percentages are based on the sums rather than the yearly data. 3 Excludes 1977 data for Michigan because type of situation found was coded fire explosion. insufficient information available to classify further (1) for all. Damage extending beyond the area of origin in a one-room building is recorded as confined to the structure of origin. Also, a fire on the roof or outside wall of a building is recorded as confined to structure of origin (National Fire Data Center 1978b). In many one- and two-family dwellings, there is only one floor and no firerated compartment of origin. Fires in these structures are all listed as confined to structure of origin once the fire extends beyond the room of origin. Thus, the high percentage for confined to structure of origin (6) does not necessarily reflect fires extending beyond the floor of origin or even the room of origin. Also, the no damage of this type (9) for smoke, water, and fire control damage is used when the structure is burned to the ground. Population at Risk An evaluation of the safety of heavy timber structures or safety of different occupancies could not be made using the data in this study because there is no measure of the population at risk. The frequent occurrence of residential and agricultural products storage fires is quite likely to result from the relatively large number of these occupancies rather than from any inherent fire hazard. In addition, lack of information on the number of properties at risk makes it difficult to use the extent-of-damage data. As mentioned previously, a fire in a oneroom building will be recorded as confined to the structure of origin once the fire extends beyond the area of origin. In contrast, a multiroom, multifloor structure requires the fire penetration of walls and floors before a fire in it is recorded as confined to the structure of origin. Furthermore, it is difficult to measure the population at risk when the exact types of structure being classified as heavy timber are not known. As a result of these unknowns, it wag not possible to achieve the objective of this study. Because a large, portion of the data was one- and two-family dwellings and agricultural products storage, some of the findings on these are reported in the appendix. 5

8 Conclusions Literature Cited Based on the data reported in this paper, we reach several conclusions regarding the reporting of heavy timber fires in the National Fire Incident Reporting System. We concluded that: 1. The coding for type of construction needs to be clarified and improved. In particular, the requirements for a structure to be coded heavy timber should be more clearly specified or modified to differentiate between Type IV buildings and other structures with large wood members. 2. The coding for the extent of damage needs to be improved so the frequency of wall and/or floor penetration can be obtained from the data. 3. Guidelines for users of the data should be developed so users have an understanding of the limitations and peculiarities of the data. 4. Most NFlRS fires reported as involving heavy timber structures occur in one- and two-family dwellings and agricultural products storage structures (barns and stables). These structures probably do not meet the building code, or NFPA 22, definition of heavy timber (Type IV construction). 6

9 Appendix As discussed in the report, the heavy timber reported as one- and two-family dwellings and agricultural products storage fires probably do not involve Type IV heavy timber structures. They probably represent fires in other types of structures with heavy timber members, such as pole structures, post and beam structures, and log cabins. Since the data provide some information on fires in one- and twofamily dwellings and agricultural products storage buildings, a summary of the findings are given in this appendix of the report. One- and Two-Family Dwellings In the 5-year period, there were 2,361 reported involving one- and two-family dwellings (table Al). Of these, 2 percent were exposure fires. The injuries were about half civilian and half fire service. There were an average 42 civilian injuries per 1,. For all reported NFIRS dwelling fires (FEMA n.d. a, n.d. b), there were 38 injuries per 1,. Only one of the 27 deaths in coded as heavy timber was a fire service death. On average, there were 11 civilian deaths per 1, coded as heavy timber. For all reported NFIRS dwelling fires (FEMA n.d. a, n.d. b), there were 8 civilian deaths per 1,. On the average, the dollar loss reported was $8,8 per incident coded as heavy timber. For all reported NFIRS dwelling fires (FEMA n.d. a, n.d. b), the average dollar loss was $4,96 per incident. These values for injury, death, and dollar loss are for reported fires. Generally, lower numbers per incident are reported when estimates for the unreported fires are included in the calculations. Heating was the major cause of fire in the one- and two-family dwellings (table A2). In addition, heating caused most dollar loss, most injuries, and most fatalities. Our determination of the cause of the fire is based on the NFIRS coding for equipment involved in ignition, form of heat of ignition, type of material ignited, ignition factor, and exposure number (Kraft and Collins 198). In a common scenario of fire involving a heating system, the cause was a mechanical failure or malfunction, or a deficiency of design, construction, or installation, as a result of which the heat from the fuelfired, fuel-powered object ignited the wood structural component or finish. Apart from heating-system fires, a common scenario was mechanical failure or malfunction resulting in heat from electrical equipment arcing or overloaded electrical equipment igniting wood structural component or finish. Incendiary or suspicious fires, electrical distribution fires, and cooking fires were the other leading types of fire. Based on these data, smoking was only the fifth leading cause of fire in the one- and twofamily dwellings. Residential fires are the number one fire problem in the United States. In 1978, residential fires were responsible for about 88 percent of all structure fires and 88 percent of the civilian deaths in structure fires (FEMA 1982). Based on the data for all residential fires, smoking is the leading cause of civilian fire deaths and heating is second (National Fire Data Center 1978a). As with one- and two-family dwellings coded as heavy timber, heating is the dominant cause of fires in all residential fires. Fire caused by heating equipment was also the main cause of injuries and fatalities in the one- and twofamily dwelling fires coded as heavy timber. Given that these heavy timber structures are probably log cabins, pole structures, and other similar types of building, there is probably a greater proportion of alternative or auxiliary heating devices in these structures than in wood frame one- and two-family dwellings. Although the point was not investigated, it is at least possible that the one- and two-family dwellings coded as heavy timber occur predominantly in rural areas. Evidence indicates a higher fire death rate in rural areas than in nonrural areas. Klem (1984) considers that the higher death rate from heating equipment than from other fires largely explains the higher rural death rate from fire. The rural heating fire fatalities are associated predominantly with solidfueled heating equipment (Gomberg and Clark 1982). The death rates due to smoking or open flame are only slightly higher in rural than nonrural areas. In 51 percent of the, the method of extinguishment was with preconnected hose line(s) with water carried in apparatus tanks (5), as would be required in rural areas. In only 16 percent of the, the water for the preconnected hose line(s) was from hydrant, draft, or standpipe (6). The possibly greaterthan-average proportion of rural offers one explanation for the higher death and injury rates, and average dollar loss, for the coded as heavy timber compared with the average for all dwelling. Because the coded as heavy timber come predominantly from certain States, we must consider differences in the geographical distribution of the among the reporting States. We do not know whether the States reporting coded as heavy timber are representative of States that reported dwelling fires. Any differences in the distribution of the reported causes of fire affect the averages because rates of death, injury, and dollar loss are correlated with the cause of fire. In a study of a limited sample of fires involving alternative- or auxiliaryheating equipment, the fires most commonly involved solid- fuel heaters (Jones and Heck 1983). These heaters included fireplaces, fireplace inserts, wood-burning and coalburning stoves. In most of these fires, improper inspection and/or lack of cleaning of the stove pipe and chimney led to an accumulation of creosote which ignited. Peacock (1979) reviewed reported fire involving wood-burning appliances and concluded that the major risks associated with the equipment were attributable to improper installation of woodburning appliances and insufficient care in their use. Heating fires in one- and two-family dwellings are steadily increasing in number and are responsible for a percentage of the fires in these dwellings that has increased from 22 percent in 1977 to 31 percent in 1981 (Jones 1982). 7

10 Table A-1. Overall summary for one- end two-family dwelling Number per 1, Yearly totals Total number Mean Standard Incidents Exposures Fire service injuries Other injuries Fire service deaths Other deaths Dollar loss , ,888,688 3,65,379 4,193, ,738 6,56,911 21,516,656 8,799, 661, Table A-2. Causes of fires in one- and two-family dwellings Number Rank Cause o f Mean Percentage of 1 Standard Total dollar loss $1, Number of injuries Number of fatalities 1 Heating , Incendiary, suspicious , Electrical distribution , Cooking Smoking Children playing Natural Exposure Appliances, air conditioning Other heat, flame, spark Open flame, ember, torch 12 Other equipment Unknown $7, Values for ranked items are percentages of all whose cause was determined and reported; and for those of unknown cause are percentages of all. Mean and standard values are based on the data for each of the 5 years. Solid-fuel heating equipment was the sprinkler equipment limits the extent Agricultural Products Storage main factor also in the 1977 to 1981 increase in the number of heating fires. In the one- and two-family dwelling fires coded as heavy timber discussed here, the percentage of fires in which heating was the cause increased from 38 percent in 1977 to about 48 percent in 1979, 198, and Active fire prevention education regarding wood-burning equipment operation and enforcement of code requirements for their installation will help to reduce the number of heating fires. Data on sprinklers and smoke detectors were limited because of the large number of fires in which no detector or sprinkler equipment was present. The available data were consistent with the hypothesis that the presence of smoke detectors and of damage when there is a fire. An assessment of the impact of using detectors and sprinklers in residential occupancies (Budnick 1984) concluded that their use is of significant benefit in terms of life and safety. In a 1977 survey, 2 percent of households had smoke detectors (Hall 1982). In a 1982 survey, more than two-thirds of the nation s households had smoke detectors (Jones 1982). With increased use of smoke detectors and the introduction of sprinkler technology to residential occupancies, the actual benefits of sprinklers and detectors should become more apparent in future fire incident data. However, increased use of detectors may be increasing the number of unreported (FEMA n.d. b). There were 1,499 of fire in agricultural products storage reported in the 5-year period (table A3). Of these, 4 percent were exposure fires. Of the 169 injuries, 67 percent were suffered by firefighters. Three of the four deaths were civilian. On the average, there was a $22,3 loss for each incident. Barns and stables (815) accounted for 88 percent of the-agricultural products storage structures. The remaining 12 percent consisted mainly of bulk storage of seeds, beans, nuts, and silage (811), and storage of materials for agricultural purchase (818). 8

11 The cause was deemed incendiary/ suspicious in 41 percent of the fires in agricultural products storage structures coded as heavy timber (table A4). Fires started by electrical distribution were responsible for the highest total dollar loss while those started by electrical distribution and natural causes resulted in most injuries. Commonly, ignition of structural wood component or finish occurred either in suspicious circumstances, or by misuse of heat of ignition, or by natural causes (lightning or spontaneous ignition). Heat resulting from mechanical failure of electrical distribution equipment caused the ignition of agricultural products in a number of fires. In 64 percent of the for which method of extinguishment was reported, the fires were extinguished with water carried in apparatus tanks using preconnected hose line(s) (5) and in 12 percent of the with water from hydrant, draft, or standpipe (6). For all nonresidential structures, more fires, deaths, injuries, and property loss were attributed to incendiary/suspicious than to any other cause (FEMA 1982). Storage fires represent only 2.5 percent of all structure fires (FEMA 1982). The major causes of storage fires are incendiary/suspicious (29 pct), open flame, heat (14 pct), and electrical distribution (1 pct). While the use of detectors and sprinklers has increased in one- and two-family dwellings, there has been no increase in the very small number of involving detectors or sprinkler equipment in agricultural products storage structures. Based on 1978 data, the average reported loss per fire for all storage property with spinklers was one-half of the loss for storage property without sprinklers (FEMA 1982). The data suggest possible ways to reduce fire losses in agriculturalproducts storage structures (barns and stables). The potential benefit of sprinklers and/or detectors should be investigated. Greater emphasis should be given to inspecting equipment for mechanical and electrical failures in agricultural storage facilities, as in storage facilities in general (FEMA 1982). Lightning protection also needs to be properly maintained in agricultural storage structures to reduce lightning-caused fires. Thorough investigations of incendiary/ suspicious fires are necessary to reduce their number. Table A-3. Overall summary for agricultural products storage Incidents Exposures Fire service injuries Other injuries Fire service deaths Other deaths Dollar loss Yearly totals Number per 1, Total number Standard Mean , ,65,974 5,567,714 4,898,462 9,294,313 1,214,964 34,41,428 22,34, 3,365, Table A-4. Causes of fires in agricultural products storage structures Percentage of Number 1 Total Number Number Rank Cause of dollar of of Standard Mean loss injuries fatalities $1, 1 Incendiary, suspicious , Electrical distribution , Natural , Exposure Heating , Children playing Smoking Other heat, flame, spark Appliances, air conditioning Cooking 11 Open flame, ember, torch 12 Other equipment Unknown , Values for the different ranked items are percentages of all whose cause was determined and reported; and for those of unknown cause are percentages of all. Mean and standard values are based on the data for each of the 5 years /85 9

12 The Forest Products Early research at the Laboratory (USDA Forest Laboratory helped establish Service) has served as the U.S. industries that produce national center for wood pulp and paper, lumber, utilization research since structural beams, plywood, 191. The Laboratory, on the particleboard and wood University of Wisconsin- furniture, and other wood Madison campus, has products. Studies now in achieved worldwide progress provide a basis for recognition for its more effective management contribution to the knowledge and use of our timber and better use of wood. resource by answering critical questions on its basic characteristics and on its conversion for use in a variety of consumer applications. Unanswered questions remain and new ones will arise because of changes in the timber resource and increased use of wood products. As we approach the 21st Century, scientists at the Forest Products Laboratory will continue to meet the challenge posed by these questions.