National Fire Incident 

Reporting System 

Version 5.0 

Fire Data Analysis 

Guidelines and Issues

July 2011
National Fire Incident 

Reporting System Version 5.0 

Fire Data Analysis 

Guidelines and Issues

July 2011

U.S. Department of Homeland Security

United States Fire Administration

National Fire Data Center
NFIRS 5.0 Fire Data Analysis Guidelines and Issues iii

TABLE OF CONTENTS

INTRODUCTION...................................................................................................................................... 1

NFIRS 5.0 DATA STRUCTURE............................................................................................................... 1

MODULE-BASED SYSTEM...................................................................................................................................................... 1

NFIRS PDR FILES................................................................................................................................................................... 2

EARLIER VERSION DATA ........................................................................................................................................................ 3

DATA MANAGEMENT............................................................................................................................. 3

SUGGESTED SOFTWARE/DATABASE SYSTEMS................................................................................................................... 3

CREATING IDENTIFICATION KEYS AND SETTING REFERENTIAL INTEGRITY FOR RELATIONAL DATABASES .................... 3

UNIQUE IDENTIFIERS ............................................................................................................................................................ 3

ISSUES ................................................................................................................................................................................... 5

Referential Integrity................................................................................................................................................................................5

Numeric Data Conversion......................................................................................................................................................................5

DATA QUALITY ....................................................................................................................................... 6

NULL VALUES IN REQUIRED FIELDS..................................................................................................................................... 6

FACTOR FIELDS...................................................................................................................................................................... 6

IDENTIFYING LARGE OUTLIERS ............................................................................................................................................ 7

NFIRS 5.0 ANALYSIS CONSTRAINTS AND CONSIDERATIONS............................................................ 7

MUTUAL AID........................................................................................................................................................................... 7

CASUALTY CONSIDERATIONS................................................................................................................................................ 8

Civilian Casualties ..................................................................................................................................................................................8

Firefighter Casualties .............................................................................................................................................................................9

EMS Casualties Occurring at Fire Incidents .........................................................................................................................................9

CONFINED FIRES................................................................................................................................................................. 10

COUNTING FIRES VERSUS COUNTING FIRE-RELATED STATISTICS................................................................................... 10

TRENDS AND MULTIYEAR ANALYSES.................................................................................................................................11

NATIONAL ESTIMATES .........................................................................................................................................................11

ANALYSIS OF NFIRS 5.0 DATA............................................................................................................11

STATISTICAL CONSIDERATIONS FOR NFIRS DATA..............................................................................................................12

NULL, BLANK, AND UNKNOWN ENTRIES...........................................................................................................................12

Evaluating Fields with NULL Values ................................................................................................................................................... 12

FIRE RUNS............................................................................................................................................................................12

TOTAL FIRES.........................................................................................................................................................................13

TYPES OF FIRES BY INCIDENT TYPE ..................................................................................................................................13

Structure Fires ......................................................................................................................................................................................14

Confined Structure Fires ................................................................................................................................................................14

Nonconfined Structure Fires ..........................................................................................................................................................14

Vehicle Fires/Mobile Properties ..........................................................................................................................................................15

Outdoor Fires ........................................................................................................................................................................................15

Other Fires ............................................................................................................................................................................................15

Building Fires ........................................................................................................................................................................................16

Confined Building Fires ..................................................................................................................................................................17

Nonconfined Building Fires ............................................................................................................................................................17

TYPE OF FIRE BY PROPERTY USE.......................................................................................................................................18

Property Use Issues............................................................................................................................................................................. 18

Residential Fires.................................................................................................................................................................................. 18

Residential Property Fires ............................................................................................................................................................. 19

Residential Structure Fires............................................................................................................................................................ 19

Residential Building Fires.............................................................................................................................................................. 19

Nonresidential Fires ............................................................................................................................................................................ 19

Nonresidential Property Fires ....................................................................................................................................................... 20

Nonresidential Structure Fires...................................................................................................................................................... 20

Nonresidential Building Fires........................................................................................................................................................ 20
iv NFIRS 5.0 Fire Data Analysis Guidelines and Issues

TABLE OF CONTENTS

OTHER PROPERTY DEFINITIONS ........................................................................................................................................20

Manufactured Homes ......................................................................................................................................................................... 20

Vacant/Under Construction Buildings, Nonconfined Fires................................................................................................................21

Occupied Buildings, Nonconfined Fires..............................................................................................................................................21

CASUALTIES..........................................................................................................................................................................22

Civilian Casualties ............................................................................................................................................................................... 22

Civilian Fire Injuries (from Civilian Fire Casualty Module)........................................................................................................... 22

Civilian Fire Deaths........................................................................................................................................................................ 22

Firefighter Casualties .......................................................................................................................................................................... 23

Firefighter Injuries.......................................................................................................................................................................... 23

Firefighter Deaths. ......................................................................................................................................................................... 23

DETERMINING CAUSE .........................................................................................................................................................23

Structure Fires ..................................................................................................................................................................................... 23

Three-Level Structure Fire Cause Hierarchy................................................................................................................................. 25

Mid-Level Structure Fire Cause Hierarchy in Hierarchical Order ................................................................................................ 26

Using the NFIRS Cause Categories .....................................................................................................................................................27

Vehicle, Outside, and Other Fires....................................................................................................................................................... 28

Cause of Fire Versus Cause of Fire Death/Fire Injury ...................................................................................................................... 28

Children Playing................................................................................................................................................................................... 29

Smoking-Related (Smoking) Versus Smoking Materials .................................................................................................................. 29

LOSS MEASURES.................................................................................................................................................................29

ANALYSIS OF COMMON DATA ELEMENTS..........................................................................................................................30

Deaths and Injuries............................................................................................................................................................................. 30

Civilian. ........................................................................................................................................................................................... 30

Firefighter. ...................................................................................................................................................................................... 30

Property and Contents Loss ............................................................................................................................................................... 30

Time of Alarm........................................................................................................................................................................................31

Month and Day .....................................................................................................................................................................................31

Time, Month, and Day of Death or Injury............................................................................................................................................31

Day of Week ..........................................................................................................................................................................................31

Elapsed (Response) Time ....................................................................................................................................................................31

Equipment Involved in Ignition ........................................................................................................................................................... 32

Fire Spread .......................................................................................................................................................................................... 32

Data Elements with Grouped Code Lists ........................................................................................................................................... 32

Multiple Entry Data Elements............................................................................................................................................................. 33

Smoke Alarms...................................................................................................................................................................................... 34

Smoke Alarms in Confined Fires................................................................................................................................................... 35

Smoke Alarms in Nonconfined Fires ............................................................................................................................................ 36

Automatic Extinguishing Systems .......................................................................................................................................................37

APPENDIX A: HIERARCHICAL CAUSE MATRIX ...............................................................................A-1

APPENDIX B: GENERAL INCIDENT GROUPING BY INCIDENT TYPE AND PROPERTY USE............B-1

APPENDIX C: NFIRS PDR FILE LAYOUTS..........................................................................................C-1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 1

NFIRS 5.0 DATA STRUCTURE

INTRODUCTION

This document discusses analytic considerations and methods of analyzing fire incident data using the U.S. Fire 

Administration’s (USFA’s) National Fire Data Center’s (NFDC’s) National Fire Incident Reporting System (NFIRS), 

Version 5.0. The topics include the NFIRS 5.0 data structure, general quality assurance (QA) issues, and definitions and parameters of common fire analyses (e.g., residential structure fires or fires by a specific cause). 

The methods, techniques, and considerations discussed are those used by USFA analysts and do not necessarily 

reflect methods, techniques, and considerations used by fire data analysts from other agencies and organizations. 

NFIRS data partners may (and do) employ their own methods for analyzing the data and may make differing assumptions when encountering data issues.

NFIRS 5.0 DATA STRUCTURE

This section notes some elements of the NFIRS 5.0 data structure that must be understood for general analysis. 

The complete structure of NFIRS 5.0 is detailed in the NFIRS Version 5.0 System Documentation. The most recent version 

of the system documentation is on the USFA NFIRS website, at http://www.nfirs.fema.gov/documentation/.

NFIRS has undergone several major changes in its 35 years of existence. Originally designed to collect fire incident 

data, the current version is an “all incident” reporting system. Fire departments can report on the full range of 

their activities, from fire to emergency medical services (EMS) to equipment involved in the response.

Module-Based System

There are currently 11 modules in NFIRS. The Basic Module is the main module, which is completed for every 

incident. The other modules are filled out, when appropriate, to provide additional information on an incident. 

All 11 modules are listed below:

Module Description

Basic Module General information for each incident

Fire Module Fire incident information 

Structure Fire Module Information on structure fires

Civilian Fire Casualty Module Fire-related injuries or deaths to civilians

Fire Service Casualty Module Injuries or deaths to firefighters

EMS Module Medical incidents

Hazardous Materials Module Hazardous materials incidents

Wildland Fire Module Wildland or vegetation fires

Apparatus/Resources Module Apparatus-specific information

Personnel Module Personnel associated with apparatus 

Arson Module Intentionally-set fire information

Data from the modules are grouped together each calendar year to create the Public Data Release (PDR) files 

which are then released annually. The PDR files consist of a subset of the data fields contained within the NFIRS 

national production database. For example, data elements with sensitive or identifying information are removed 

as are data elements that are wholly used for maintenance or production purposes. The PDR files’ data structure 

has been considerably simplified from the production database for ease of use. The PDR files from 2004 to the 

present only include fire and hazmat incidents and their related data tables. Prior to 2004, all incidents were 

included in the PDR files.
2 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

NFIRS 5.0 DATA STRUCTURE

In its basic form, the NFIRS PDR files have a relational data structure where data from each incident module 

is represented by a row in a data table. The primary tables (basic incident and incident address) contain most 

of the Basic Module data. There is exactly one record in the basic incident table for every incident reported to 

NFIRS. All other modules, represented by data tables with similar names (fire incident, civilian casualties, etc.), 

have records that are linked to the basic incident table through unique incident identification key fields (e.g., 

STATE, FDID, INC_DATE, INC_NO, and EXP_NO). Some module data are split across several tables (e.g., basic 

incident, incident address, and basic aid tables); one table (fire incident) combines data from two modules (i.e., 

Fire Module and Structure Fire Module). Some tables, such as fire incident, will only have one record for each 

relevant incident in the basic incident table, while tables such as civilian casualty may have several records 

linked to a single incident in the case where multiple injuries and/or deaths occur in the same incident. The 

Apparatus/Resources and the Personnel Modules are not available for public release and are not represented in 

the PDR files.

The NFIRS PDR files contain the NFIRS 5.0 PDR data table relationship diagram which details the relationships 

between the data files.

NFIRS PDR Files

Currently, 19 data tables (files) in .dbf format are included in the NFIRS PDR files. The tables are generally 

known by their common name/description. As each table is introduced, the database filename is included in 

parentheses. The common names and database table file names are used interchangeably.

The table below should be used as the reference between the common names and the database table file names.

PDR Database File Description NFIRS Module(s)

arson.dbf

arsonagencyreferal.dbf

arsonjuvsub.dbf

basicaid.dbf

basicincident.dbf

civiliancasualty.dbf

codelookup.dbf

ems.dbf

fdheader.dbf

ffcasualty.dbf

ffequipfail.dbf

fireincident.dbf

hazchem.dbf

hazmat.dbf

hazmatequipinvolved.dbf

hazmobprop.dbf

incidentaddress.dbf

legacyfields.dbf

wildlands.dbf

Arson incident

Arson agency referral

Arson juvenile subject

Basic incident aid (given/received)

Basic incident (primary data file)

Civilian casualty

Code descriptor lookup

Emergency medical service incident

Fire department information

Firefighter casualty

Firefighter equipment failure

Fire incident

Hazardous material chemical involved

Hazardous material incident

Hazardous material equipment involved

Hazardous material mobile property type

Basic incident address

NFIRS 4.1 legacy field

Wildland fire incident

Arson

Arson

Arson–Juvenile Firesetter

Basic

Basic

Civilian Fire Casualty

Reference

EMS 

Reference

Fire Service Casualty

Fire Service Casualty

Fire and Structure

Hazardous Materials

Hazardous Materials

Hazardous Materials

Hazardous Materials

Basic

Reference

Wildland Fire

The dBASE (.dbf file) format is the only format available for the PDR files.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 3

DATA MANAGEMENT

Earlier Version Data

During the transition from the previous version, NFIRS included data collected in the previous format (NFIRS 

4.1) and then converted to NFIRS Version 5.0 by the system. For many 4.1 fields and codes, there are oneto-one code conversions that did not change the nature of the original data. However, the analyst should be 

aware of data that cannot be converted directly, or where 4.1 data are interpreted rather than directly converted. The 4.1 to 5.0 conversion rules are documented within the National Fire Incident Reporting System Version 5.0 Design 

Documentation, (http://www.nfirs.fema.gov/documentation/design/NFIRS_Spec_2009.pdf).

As of January 1, 2009, NFIRS no longer accepts converted 4.1 data.

The USFA has recommended that where a specific research question rests on the correct interpretation of these 

specific codes, the analyst should restrict the analysis to NFIRS Version 5.0 data. Incident Type (INC_TYPE) 

110, undefined structure fire, is a 4.1 conversion code. Incidents in the NFIRS 5.0 database with a 110 Incident 

Type are incidents collected under the NFIRS 4.1 system and are converted to NFIRS 5.0 compatible data. Beginning with the 2002 NFIRS data, USFA staff uses only Version 5.0 in their analyses. Therefore, Incident Type 

110 is excluded. These codes are documented in the NFIRS 5.0 Design Document data dictionary section and 

designated there as “conversion only” codes.

The original 5.0 and converted 4.1 data could be aggregated with the caveats above and with an understanding 

of the code conversions for users interested in broader research inquiries.

DATA MANAGEMENT

This section presents an overview of NFIRS data import issues, use of software/database systems, and ideal 

software requirements. 

Suggested Software/Database Systems

Database software, system, or statistical software packages for large database manipulation are required to 

import and use the NFIRS PDR files since the data files are extremely large and are released in dBASE format 

(.dbf). Some candidates for use are MySQL, Microsoft® SQL Server, Statistical Analysis Software (SAS), Statistical Package for the Social Sciences (SPSS), Microsoft® Access, and Oracle.

While current Excel or other spreadsheet programs can be used to open the data files, the use of Excel is not 

optimal for manipulating the data.

Creating Identification Keys and Setting Referential Integrity 

for Relational Databases

If a relational database is chosen as the preferred system, the user needs to be aware that the PDR files do not 

contain a preset identification (ID) key. Relational database systems use ID keys to match records from table 

to table. For instance, a basic incident (basicincident.dbf) record may have a related fire incident (fireincident.

dbf) record and multiple civilian (civiliancasualty.dbf) or firefighter casualty (ffcasualty.dbf) records. To match 

all of these records together in one query, all of the tables must have ID keys set to link them together.

Unique Identifiers

Records in the PDR files have unique identifiers that follow the pattern in the NFIRS 5.0 PDR Table Relationship Diagram as follows.
4 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

DATA MANAGEMENT

NFIRS 5.0 PDR Table Relationship Diagram 8/26/2004

FDHeader.dbf

1 to Many BasicIncident.dbf

1 to 1 FireIncident.dbf

1 to Many CivilianCasualty.dbf

1 to Many HazChem.dbf

1 to Many HazMobProp.dbf

1 to Many HazMatEquipInvolved.dbf

1 to Many ArsonJuvSub.dbf

1 to Many ArsonAgencyReferal.dbf

1 to 1 EMS.dbf

1 to 1 Wildlands.dbf

1 to 1 HazMat.dbf

1 to 1 Arson.dbf

1 to 1 IncidentAddress.dbf

1 to Many BasicAid.dbf

1 to Many FFCasualty.dbf

1 to Many FFEquipFail.dbf

The fire department header table (fdheader.dbf) unique identifier is the combination of the State and fire department ID (STATE, FDID):

Key Field Description Data Type Length

STATE Fire Dept. State C 2

FDID Fire Dept. ID X 5

Source: Public Data Release Format v1_5. 

Note: C = character; X = mixed character and numeric; N = numeric.

The next level of tables—basic incident (basicincident.dbf), fire incident (fireincident.dbf), emergency medical 

services incident (EMS.dbf), wildlands (wildlands.dbf), hazmat (hazmat.dbf), arson (arson.dbf), and incident 

address (incidentaddress.dbf)—all share the same unique identifier format. These tables have a one-to-many 

relationship with the fdheader table. The unique identifier for these incident-associated records is the combination of the State, fire department ID, incident date, incident number, and exposure number (STATE, FDID, 

INC_DATE, INC_NO, and EXP_NO). This combination of fields ensures that every incident has a unique 

reference regardless of differences in recordkeeping between fire departments across the country. For example, 

the basic aid (basicaid.dbf), hazmat mobile property (hazmobprop.dbf), and hazmat equipment involved 

(hazmatequipinvolved.dbf) tables also share this key, but it is not a unique key.

The ID key is used to join different tables in the database together. In some tables, there is a one-to-one match. 

In others, there is a one-to-many match. For these tables (one-to-many), there are additional sequence fields 

that need to be included as part of the ID key as shown below.

Key Field Description Data Type Length

STATE Fire Dept. State C 2

FDID Fire Dept. ID X 5

INC_DATE Incident Date N 8 (MMDDYYYY)

INC_NO Incident Number X 7

EXP_NO Exposure Number N 3

Source: Public Data Release Format v1_5. 

Note: C = character; X = mixed character and numeric; N = numeric.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 5

DATA MANAGEMENT

The following tables require an additional field(s) to create a unique identifier: 

Table Additional Key Field Data Type Length

civiliancasualty.dbf SEQ_NUMBER N 3

hazchem.dbf SEQ_NUMBER N 3

ems.dbf PATIENT_NO N 3

arsonjuvsub.dbf SUB_SEQ_NO N 3

arsonagencyreferal.dbf AGENCY_NAM X 30

firefightercasualty.dbf FF_SEQ_NO N 3

ffequipfail.dbf CAS_SEQ_NO

EQP_SEQ_NO

N

N

3

3

Source: Public Data Release Format v1_5. 

Note: C = character; X = mixed character and numeric; N = numeric.

The key fields are also identified in the NFIRS Public Data Release Format (Version 1.5) that accompanies the 

PDR files. This format is also included as Appendix C.

Issues

Referential Integrity

Data cannot be imported directly into an existing NFIRS relational database with established referential integrity because the NFIRS .dbf data tables do not contain ID keys. A relational database with referential integrity 

requires that the primary table, basic incident, contain unique ID keys and all records in related tables (e.g., 

fire, casualties) have ID keys that exactly match one record in the basic incident table. USFA does not currently have a QA process to check for inconsistencies in the key fields in the NFIRS basic incident table or in 

related tables.1 Therefore, if the data are to be imported into a database, it is suggested to import the data into 

a secondary or test database to create and confirm the uniqueness of the keys and resolve any duplicate or mismatched ID keys. A case sensitive collating sequence must be used as upper and lower case letters can appear 

in the incident number field. Once the ID keys are established and verified, the tables can then be imported or 

copied into the primary database without causing referential integrity errors. 

Setting referential integrity is not required to create the database or to do analysis of the NFIRS data. However, 

without it, analysts will need to conduct a QA check of the data for mismatched records. Referential integrity is 

therefore a useful step in ensuring the quality of the data. Most database systems have tools for setting referential integrity between tables, often using a graphic interface to visually depict the database model.

If other packages (e.g., SAS) are chosen, this step may not be necessary.

Numeric Data Conversion

Data conversion from numeric to date-time data may be necessary for the various date-time data elements. Automatic conversion of numeric data to a text field may convert the data to an integer type, which will truncate 

the leading zero and additional data massaging may be necessary.2

1 Depending on the database system, these records may need to be removed or the entire import process may fail. 2 For example, an alarm on 01/01/03 at 13:15 (1:15 p.m.) would be formatted as “010120031315” in a text field. Converting this date-time 

data to an integer type would truncate the leading zero to produce the number 10,120,031,315.
6 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

DATA QUALITY

Depending on the database environment, other numeric elements may need to be reviewed for appropriate 

data type matches.

Care needs to be taken to ensure the proper importation of fields with null (blank) values. Null values exist in 

NFIRS and are not equivalent to zero. Some database products will automatically convert null values to zeros if 

care is not taken on the import of data. This will be disastrous for the dollar-loss fields and any other numeric 

field where a null value represents “unreported” and a zero means “there were none.”

DATA QUALITY

The USFA does not currently have a QA system in place to check for codes that are not in the current data dictionary. The NFIRS PDR database, as a result, contains invalid codes and may exhibit data inconsistencies that 

violate published documentation. 

The code lookup table (codelookup.dbf), which is based on the data dictionary (http://www.nfirs.fema.gov/

jsps/nfirsdownload.jsp?url=/documentation/design/NFIRS_Spec_Tables_2009.xls) can be used to validate data 

codes. Some codes are added over time, so it is important to use the most recent code lookup table.

Note that hierarchical code placeholders are used for the numeric code values in the data dictionary and in 

the code lookup table. These placeholders are not themselves valid codes used for data entry. Instead, they are 

used as section titles for code groups and are intended for use in automated pick-lists and database groupings 

used by data analysts. They should never be allowed as valid code choices for data entry and should be rejected 

as invalid by the NFIRS 5.0 edits. Some examples of code placeholders are “1 Fire” and “10 Fire, other” in the 

Incident Type (INC_TYPE) field. These placeholders, however, are not noted in either the data dictionary or 

the code lookup table. When in question, refer to the National Fire Incident Reporting System 5.0 Complete Reference Guide

(CRG) (http://www.nfirs.fema.gov/documentation/reference/). If the code in question is not in the CRG, it is 

not valid.

Null Values in Required Fields

There remain instances of null values in required fields. As NFIRS 5.0 matures, more and more of these issues 

surface and are corrected. Nonetheless, analysts should be aware that null values may occur in required fields 

and that a work-around will be necessary. Heat source and structure type are examples where null values have 

been an issue. In the case of heat source, null values typically occur in fire incidents where the Fire Module, 

that is, detailed fire-related data, is not required (confined fires and outside rubbish fires) and in vegetation, 

special outside fires, and crop fires where the Wildland Fire Module can be submitted (and heat source is not 

required). In the case of structure type, null values typically occur in fire incidents where the Fire Module is 

not required (confined fires).

If null values are found in a required field in the 5.0 data, notify the USFA NFIRS manager of the issue and the specific query or section of a 

program that was used to find the error or the specific record (noting the ID key fields) that contains the error.

Factor Fields

Several data items allow multiple entries, such as “factors contributing to ignition” and “human factors contributing to ignition.” In these cases, each entry is distinct. That is, for example, FACT_IGN_1 <> FACT_IGN_2, 

where ‘<>’ means not equal. There have been instances when this rule has not been applied correctly or the 

edit check to catch the error has not worked properly. Again, if errors are found, notify the USFA NFIRS manager of the 

issue and the specific query that was used to find the error or the specific record (noting the ID key fields) that contains the error.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 7

NFIRS 5.0 ANALYSIS CONSTRAINTS AND CONSIDERATIONS

When analyzing the frequency of these factors, the convention established has been to include all factors 

mentioned in the data in the frequency distribution. That means the total number of factors (the denominator) 

may exceed the number of incidents (or casualties, depending on the factor series under analysis).

The analyst has several choices for techniques:

•	 Query the data for the distribution of each subfactor variable where the factor is specified. For the example 

above, this constraint is where FACT_IGN_X is between 00 and 75 and ensuring no duplicates exist between the factors in an incident. Then, add the results of the queries together. The results from each query 

are appended in an Excel spreadsheet, sorted by the FACT_IGN_X column and subtotaled for each factor 

value. Because the total number of factors may exceed the number of incidents, the percentage distribution 

for the sum of the factors will exceed 100 percent. Percentages can then be derived using the sum of the 

first factor as the denominator. (Other methods can be used to achieve the same result.)

•	 Write code to capture and count each occurrence of the factor code across the variable. 

•	 Manipulate the input data to create a new data table, file, data vector, or other schema that collapses the 

multiple fields. Perform the analysis on this user-created schema.

This topic is addressed further in a later section, Analysis of Common Data Elements, that addresses specific data (i.e., 

Multiple Entry Data Elements) elements and how USFA analyzes and interprets the results of the analyses.

Identifying Large Outliers

If the record clearly contains bad data, use a unique value (such as the ID key) to exclude the record from the 

query. Before excluding such records, however, it is suggested that a quick search be conducted to see if some 

unusual fire did occur. Searching a reputable Internet search engine by the date, State, and the word “fire” will 

usually produce a news account if a large fire did, in fact, occur.

NFIRS 5.0 ANALYSIS CONSTRAINTS 

AND CONSIDERATIONS

The following sections discuss constraints and issues related to querying and analyzing NFIRS 5.0 data.

Mutual Aid

Some records in NFIRS refer to aid provided to another fire department, either mutual aid given to an outside fire service entity upon request of the outside entity (AID = 3) or automatic aid given through mutual-aid 

agreements (AID = 4). To isolate individual fire incidents, only records of the primary fire department are 

included. This is achieved by excluding records reflecting aid provided, i.e., excluding records with AID = ‘3’ 

or ‘4.’ In essence, not excluding aid incidents when analyzing incidents will result in the double counting of those 

incidents where both the giving and receiving departments report to NFIRS. 

Mutual-aid given incidents (AID = 3 or 4) should always be excluded from all queries with one major 

exception: when counting firefighter casualties. Fire departments report only their own firefighter casualties 

and not those of a mutual-aid department. Thus, to capture all firefighter injuries, both the incident where the 

department received aid and the incident where the department provided aid must be included.

To reiterate, if counting fire service casualties, include aid-given incidents since each fire department (regardless of giving or receiving aid) responding to an incident reports its own firefighter casualties; for everything 

else, exclude them.
8 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

NFIRS 5.0 ANALYSIS CONSTRAINTS AND CONSIDERATIONS

Other aid-given (AID = 5) incidents should always be included in all analyses. This code is for incidents 

where the aid-giving department is responding to an area that has no fire department of its own (for example, 

west Texas). The giving department completes the entire incident report just as if it had occurred in its own 

jurisdiction. That incident report is the one and only copy of the incident reported in NFIRS since there is no 

aid-receiving department. For that reason, other aid-given (AID = 5) incidents must always be included in 

queries. Only mutual aid-given (AID = 3 or 4) incidents must be excluded (again, except when counting firefighter casualties).

Casualty Considerations

Civilian Casualties

Civilian casualties (i.e., injuries and deaths) are tallied in the basic incident table and the details of each casualty are reported in the civilian fire casualty table. To indicate the type and level of the casualty, a 6-level severity 

scale (SEV) is used. While civilian injuries have severity values of 1-4, undetermined (U) entries in severity are 

also included in the analysis of civilian injuries. Null entries in severity are excluded in analyses of civilian fire 

injuries as SEV is a required field. Civilian deaths are noted as SEV = 5. The civilian casualty severity codes are 

shown below:

Severity Scale Definition

1 Minor

2 Moderate

3 Severe

4 Life Threatening

5 Death

U Undetermined

While the CRG instructs a department completing the Basic Module to include only civilian casualties that are 

fire-related, there is a potential issue with counting EMS casualties as civilian fire casualties (see “EMS Casualties Occurring at Fire Incidents”). There are two methods that can be used to derive the number of actual 

civilian fire-related casualties:

•	 Where the incident type is “fire” (i.e., INC_TYPE in the 100 series), the civilian death (OTH_DEATH) and 

injury (OTH_INJ) fields from the basic incident table can be summed, or 

•	 The number of civilian fire casualty records for each incident can be totaled from the civilian casualty table. 

Each of these methods has drawbacks. The first method is the most straightforward, but there is a chance that 

the fire incident may also have nonfire-related EMS casualties which are also included in the total—most likely 

a small number, especially since the NFIRS training at the National Fire Academy (NFA) and the National Fire 

Information Council (NFIC) reinforces the CRG directions by instructing firefighters and other personnel to 

record only civilian fire casualties on the Basic Module Form. To ensure that only fire-related casualties are 

included, only fire incidents (i.e., INC_TYPE in the 100 series) are considered.

The second method ensures that only true civilian fire casualties are included in the total but may exclude 

some fire casualties because the casualty was reported in the Basic Module but no matching Civilian Fire Casualty Module entry was completed. NFIRS does not require a Civilian Fire Casualty Module to be completed 

for each casualty reported on the Basic Module because it may be EMS-related, not fire. Analysts have a choice 

between a number that may be slightly high but includes all civilian fire casualties, or a number that may be 

low because not all casualties reported on the Basic Module have a matching civilian fire casualty record.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 9

NFIRS 5.0 ANALYSIS CONSTRAINTS AND CONSIDERATIONS

Firefighter Casualties 

As a reminder, unlike civilian casualties and fire counts, mutual aid-given incidents must be included when 

using the basic incident table to identify fire service casualties. See the section above on Mutual Aid.

Fire service casualties are tallied in the Basic Module and the details of each casualty are reported in the Fire 

Service Casualty Module (regardless of incident type). The SEVERITY field (1-7) is used to indicate the type and 

level of the casualty. Fire service deaths in the firefighter casualty file are those with SEVERITY = 7. 

NFIRS 5.0 fire service incidents with SEVERITY = 1 are not casualties. This code indicates a report that the 

firefighter has been exposed to something that might be harmful to his health at some point in the future 

(asbestos, for example). As such, SEVERITY = 1 records are only intended for local fire department documentation of such exposures and are not included as firefighter injuries in data analyses at the national level.

All other SEVERITY entries are considered injuries with the follow exception:

Prior to 2005 NFIRS data, firefighter injuries with null SEVERITY values are included as injuries. Starting 

with 2005, firefighter injuries with null severity values are excluded in the injury analyses. SEVERITY became 

a required field as of 2005; null values are considered to be invalid entries.

Reported firefighter deaths in NFIRS are fairly rare compared to reported injuries. The valid firefighter casualty 

severity codes are shown below:

Severity Scale Definition

1 Report only, including exposure

2 First aid only, no lost time

3 Treated by physician, no lost time

4 Moderate severity, lost-time injury

5 Severe, lost-time injury

6 Life threatening, lost-time injury

7 Death

EMS Casualties Occurring at Fire Incidents

As NFIRS 5.0 does not have EMS-specific casualty fields on the Basic Module, it is possible that the civilian 

casualty counts and fire casualty counts include some EMS casualties, even when the incident type is ‘fire.’ This 

is only possible when a fire incident also includes EMS casualties. This is thought to be a rare event.

Since some EMS fatalities may be included in the Basic Module counts in NFIRS 5.0, there may not be one-toone comparisons with the counts in the Basic Module and the number of records in the civilian fire casualty 

table or the fire service casualty table. However, there cannot be more injuries or more deaths in the casualty 

modules than the counts in the Basic Module.

Therefore, the counts on the Basic Module may be high due to the inclusion of EMS casualties in the casualty 

counts and the number of casualty table records (both in the civilian and firefighter casualty tables) may be 

less because its completion is no longer enforced.

USFA recommends the use of the basic incident table casualty counts for the following reasons:

1. The NFIRS training classes teach departments only to report fire casualties on the Basic Module, so theoretically, most will be doing it correctly.
10 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

NFIRS 5.0 ANALYSIS CONSTRAINTS AND CONSIDERATIONS

2. The cases where fire and EMS casualties coexist should be fairly rare.

3. It is less likely that the casualty module will be completed and that may represent a substantial undercount.

Confined Fires

Confined fires (Incident Type, INC_TYPE, codes 113–118) do not require a Fire Module and often have no 

civilian casualty modules. This results in an increase in the proportion of unknown values when distributing 

queries by fire incident or civilian casualty fields (see the later section Null, Blank, and Unknown Entries). There are 

two options that could be pursued to ensure that the confined fire null values do not have an undue influence 

on the unknown values:

•	 Limit the analysis to nonconfined fires or to only fires that have a Fire Module (some confined fires do 

have fire incident records).

•	 Separate the analyses into a confined fires version and a nonconfined fires version. The resulting analysis 

will be very generic but there are instances where this is reasonable.

USFA generally uses the second option. The exception is when the number of confined fires is very small and 

the inclusion or exclusion of them does not significantly change the analysis. In this case, the analysis may or 

may not include the confined fires, depending on the judgment of the analyst.

Note that while the NFPA survey includes a category for confined fires, NFPA does not publish estimates of 

confined fires. It is unclear what the effect of this has on estimates derived from NFIRS datasets that include 

confined fires. An example of one such estimate would be on the number of fires with smoke alarms present, 

but not working. The Basic Module gives some information on smoke alarm presence and operation, but not 

complete information. The Fire Module gives additional information such as operational status, effectiveness, 

power supply, type of alarm, and detector failure reason. 

Counting Fires Versus Counting Fire-Related Statistics

When the variable in question is a fire-related variable (i.e., captured under the fire modules—fire, structure 

fire, wildland, etc.), fires are counted. When the variable in question is in the casualty modules, casualties are 

counted. Even the most seasoned fire data analyst may overlook this distinction from time to time. The proper 

phrasing/analysis for casualties counted from fire variables is “fires with casualties/injuries/deaths” or an 

equivalent statement. 

An example of this is when looking at fatal fires (those fires that result in fatalities) and the fatalities themselves. These two types of analyses are very different. Fatal fires investigate the fire-related variables to analyze 

information about the fires that resulted in fatalities. The variables used in the analyses are from the Fire Module. Whereas when analyzing fatalities, the casualties are examined, not the fire. The variables in question are 

contained in the casualty modules. As there is a one-to-many relationship between fires and casualties, the 

distinction between the analysis of the fire and the analysis of the result of the fire is an important one.

In this vein, analyses such as fires with deaths/injuries, fires causing/resulting in deaths/injuries, and the like 

focus on the fire. Analyses such as “fatalities” and “injuries” focus on the casualty.

Fires with loss—property and contents—can also be analyzed separately from fires with no loss reported. Loss 

is often difficult to quantify at the incident scene. Often, it may be estimated or not reported at all. As a loss report is not required for all fires, there is some debate whether the appropriate analysis is to treat loss across all 

fires, only for those fires where loss is specified, or to derive an average loss and apply it to fires with no loss 

reported. The latter analysis assumes that, except in the instances of trash fires that do not burn items of value 
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 11

ANALYSIS OF NFIRS 5.0 DATA

(including the trash container) and some outdoor vegetation fires, any fire exacts some monetary toll associated with what was lost. 

As noted earlier, null values must be carefully imported. As well, analysts need to be aware of their system use 

of null values as some systems may produce unusual results when null values are added to numeric values. As 

well, there is an issue with the reporting of extremely small losses under the assumption that a value has to be 

reported for every fire. In short, dollar-loss analyses must be treated with extreme caution.

For instance, in 2008, a total of 368,232 fires were reported on residential properties. The total loss across these 

properties was reported as $4,654,041,727 (property and contents). Not all of the fires reported loss; this loss 

was reported from 126,001 of the fires. While the average loss reported across all residential property fires is 

$12,639, the average loss for the fires that reported a loss is $36,937—a substantial difference. Loss is considered to be 

one of the less reliable data elements in NFIRS, as it is difficult to establish dollar loss without sufficient information or records.

Trends and Multiyear Analyses

It is important to note that NFIRS data may fluctuate from year to year, resulting in variability. It is possible 

that any given year may be an anomalous year for a subset of fire data or for the data overall. Statistically rare, 

but real-world incidents do occur. Large conflagrations such as the various California wildfires, large petrochemical plant fires such as the 1989 Houston Ship Channel fire, and large multifatality, multiinjury fires such 

as the 1980 MGM Grand Hotel fire or the 2003 fire at The Station Nightclub can have one-time effects on fire 

analyses for that year.

For these reasons—yearly fluctuation and single-event spikes—it is often preferable to aggregate several years’ 

data for analyses. USFA uses 3-year averaged data and, where possible, analyzes trends of 5 or more years’ data. 

Trends are usually described by the change in the linear best fit. Moving averages are another avenue of trend 

analyses available. 

National Estimates

National estimates are estimates of the numbers of fire losses (fires, deaths, injuries, dollar loss) associated 

with a subset of the fire data. They are not the raw totals from NFIRS. These estimates are based on a method 

of apportioning the NFPA estimates for total fires and for vehicle, outside, and other fires. Generally speaking, 

national estimates are derived by computing a percentage of fires, deaths, injuries, or dollar loss in a particular NFIRS category and multiplying it by the corresponding total estimate from the NFPA annual survey. This 

methodology is the accepted practice of national fire data analysts. The specifics of the methodology are not 

discussed here but the methodology may be downloaded from the following NFPA webpage: http://www.

nfpa.org/assets/files/PDF/Research/Nationalestimates.pdf.

ANALYSIS OF NFIRS 5.0 DATA

The following section lists the parameters of common fire analyses. Each type of analysis typically involves 

multiple fields and often multiple tables. The values to search for in each field are listed individually, as a 

range of inclusive values (e.g., “100–199”), or in some cases a mix of individual values and ranges, separated 

by commas (e.g., “100, 140–199,” meaning the individual value 100 and the inclusive range of 140–199). In 

some cases, an analysis will look at most of the data in a given field, with the exception of a specific value or 

a small range of values. For example, when analyzing nonresidential properties, it is easier to simply exclude 

the residential range rather than trying to define everything else. In these examples, the excluded range will 

be prefaced with “not” (e.g., “NOT 400–499, exclude NULL”), meaning all values except the inclusive range of 

400–499 and nulls. Null values are often treated separately as noted in each section.
12 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Statistical Considerations for NFIRS Data

Any analysis of the NFIRS data should note that NFIRS is neither a random sample nor a census of fire incidents or casualties in the United States. As such, the analyst may not accurately make estimates of total fires, 

fire losses, or fire casualties in the United States from NFIRS data alone. Similarly, statistical means (averages) or 

standard error measurements taken from NFIRS describe the population of fire incidents related to fire departments that participate in NFIRS, but do not describe the population of fire incidents in the Nation as a whole.

However, the proportion of fire incidents reported to NFIRS is large enough that reasonable inferences can be 

made that the proportions of fires in NFIRS are similar to the true national measurements.

Null, Blank, and Unknown Entries

On a fraction of the incident reports or casualty reports sent to NFIRS, the desired information for many data 

items either is not reported or is reported as “unknown.” For most coded fields, ‘U,’ ‘UU,’ and ‘UUU’ are 

codes available in NFIRS 5.0 to indicate “unknown.” The total number of null, blank, or unknown entries can 

be larger than some of the important subcategories. The lack of data masks the true picture of the fire problem. 

In some cases, even after the best attempts by fire investigators, the information is truly unknown. In other 

cases, the information reported as unknown in the initial NFIRS report is not updated after the fire investigation is completed. When the unknowns are large, the credibility of the data suffers. 

In the standard analysis of NFIRS data, the approach taken is to compute two distributions: one that includes all 

entries (“raw” distribution) and one that includes only those entries for which data were provided (“known” 

distribution). This latter calculation, in effect, distributes the fires for which the data are unknown in the same 

proportion as the fires for which the data are known, which may or may not be approximately right. 

Null and blank values differ from the variously coded ‘U’ entries in several ways and, depending on the database system used, the accounting of null and blank values may need to be taken into consideration as noted. 

It is important to note that null and blank values are considered unreported data and differ in meaning and 

substance from “unknown” data. In data elements where information is required, a null or blank value may 

invalidate the record.

Evaluating Fields with NULL Values

In the Microsoft® SQL Server environment, a field must have a value to be evaluated in a query expression. 

Other platforms may not impose this requirement. This need becomes an issue when the analyst needs to 

exclude a range of values from a query. For instance, if one is counting nonresidential incidents and wishes to 

exclude the property use range 400–499, then an additional condition needs to be included (when using 2006 

to present NFIRS data) to also remove null values. 

Fire Runs

The following parameters provide the total number of NFIRS 5.0 fire runs in the database:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident INC_TYPE Type of incident 100–109, 111–199

Note that mutual-aid incidents are counted as fire runs.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 13

ANALYSIS OF NFIRS 5.0 DATA

Total Fires

Fires are designated by the 100 series Incident Type. Note again that incident type 110 is not a Version 5.0 incident type (INC_TYPE). The following parameters provide the total number of NFIRS 5.0 fires in the database:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 100–109, 111–199

Mutual-aid runs are eliminated to avoid double counting of fire incidents.

Types of Fires by Incident Type

The general categories of fire incidents are broadly defined by the type of incident. The table that follows 

shows the current designation of general fire incident categories. Parameters specific to each fire incident category (structure, vehicle, outside, and other) are discussed separately in later sections. Fires with undesignated 

incident type (INC_TYPE) codes are included in “other” fires.

Note that Incident Type 110 is not included in the following table as it is not a Version 5.0 incident.

Building fires, a subset of structure fires, are discussed in the section Building Fires.

Incident Type Incident Type Code

Structure Fires 111–123

Confined Fires 113–118

Mobile Structure Fires 120–123

Mobile Property/Vehicle Fires 130–139 (with mobile property 

involved (MOB_INVOL) of 1, 3)

Outside Fires 140–179 less 163

Natural Vegetation Fires 140–149

Outside Rubbish Fires 150–159

Special Outside Fires 160–169 less 163

Cultivated Vegetation Fires 170–179

Other Fire 100–109, 130–139 (MOB_INVOL not 1, 3), 

163, 180–189, 190–199

Other Fires 100

Undesignated 101–109

Vehicle-Related Fires Where Vehicle Itself Did Not Burn 130–139 (MOB_INVOL is NULL 

or is not 1, 3)

Outside Gas or Vapor Combustion Explosion 

Without Sustained Fire 163

Undesignated 180–189

Undesignated 190–199
14 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Structure Fires

NFIRS 5.0 has an inclusive definition of structure. A structure is a built object and can be a bridge, tower, tunnel, fence, telephone pole, building, or some other built object. Incidents related to structure fires have Incident Types in the range 111–123. The overall structure fires group includes both fixed structures (111–118) and 

mobile properties used as fixed structures (120–123). 

Note that this category also includes confined fires (INC_TYPE 113–118), which may not always occur in a 

structure or building. The following parameters provide the total number of NFIRS 5.0 structure fires:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 111–123

When analyzing structure fires, it is necessary to examine what is meant by structure. If the analysis is actually 

based on “buildings,” then the structure-type variable needs to be considered in addition to the structure fire 

incident types above. The analysis of buildings is discussed in a later section on Building Fires.

Confined Structure Fires3

NFIRS-defined confined structure fires are those fires that did not spread beyond the container of origin (e.g., 

a cooking pan fire that is put out on the stove) and are in the Incident Type (INC_TYPE) range 113–118. Confined fires rarely result in serious injury or large content losses and are expected to have no significant accompanying property losses due to flame damage. NFIRS allows abbreviated reporting for confined structure fires 

(as well as some types of confined outdoor fires) and many reporting details of these fires are not required, 

nor are they reported (not all fires confined to the object of origin are counted as confined fires). The following parameters provide the number of NFIRS 5.0 confined structure fires:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 113–118

NFIRS 5.0 is designed to encourage the reporting of small fires, such as those confined to a stove top or a trash 

can. However, it appears that fires with these codes may not be exclusively structure fires nor exclusively confined to object of origin fires. Although they are included in the structure fire range of 111–123, confined fires 

may or may not occur in a structure, e.g., confined cooking fires may occur on an outdoor patio. 

There are analytic considerations associated with confined fires. These considerations are discussed in the section Building Fires. 

Nonconfined Structure Fires

Nonconfined structure fires are those incidents typically associated with larger, more serious fires that progress beyond control and often result in substantial loss and/or casualties. The following parameters provide the 

number of NFIRS 5.0 nonconfined structure fires:

3 See also USFA’s report on Confined Structure Fires, February 2006.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 15

ANALYSIS OF NFIRS 5.0 DATA

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 111, 112, 120–123

Vehicle Fires/Mobile Properties

Vehicle fire incidents (also known as Mobile Property fires) are generally coded with an Incident Type (INC_

TYPE) in the 130 series. Additional criteria must be included to separate those incidents where the vehicle was 

involved in ignition, but did not itself burn (MOB_INVOL = 2) as well as those incidents, coded as a vehicular 

fire, but do not indicate that mobile property was involved (MOB_INVOL = N). This latter category is unusual 

and likely an error. These are fires, but the incident type is most likely miscoded as vehicle fire incidents. The 

following parameters provide the total number of NFIRS 5.0 vehicle fires:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 130–139

Basic Incident MOB_INVOL Mobile property involved 1, 3

Outdoor Fires

Outdoor fire incidents are generally coded in the INC_TYPE 140–170 ranges. The exception is INC_TYPE 163, 

“outside gas or vapor combustion explosion without sustained fire,” which is considered an “other” fire. The 

following parameters provide the total number of outdoor fires in the NFIRS database:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 140–179, less 163

For purposes of analysis, Incident Types (INC_TYPE) 154 (dumpster or other outside trash receptacle fire) and 

155 (outside stationary compactor or compacted trash fire) are considered as “confined” fires. In addition, Incident Types in the 150 series are not required to complete the Fire Module.

Other Fires

“Other” fire incidents are those miscellaneous fires that do not neatly fit into the major categories. The parameters are detailed in Appendix B, General Incident Grouping by Incident Type and Property Use and the above section, Types 

of Fires by Incident Type. The following parameters provide the total number of other fires in the NFIRS database:
16 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 100–109, 163, 

180–189, 190–199

Basic Incident INC_TYPE Type of incident 130–139

 AND

Fire Incident MOB_INVOL Mobile property involved NOT 1, 3

Building Fires

By and large, most of the structure fire incidents occur in buildings. Analysis of purely building variables, such 

as sprinklers or smoke alarms, however, require that only Structure Types 1 (enclosed building) or 2 (fixed 

portable or mobile structure) be considered. This is not only for analytic sense but also to preclude unnecessary null values. That is, only those structure fires that are buildings (Structure Type is a 1 or a 2) are required 

to provide data on:

•	 building status;

•	 building height;

•	 main floor size;

•	 fire origin;

•	 fire spread;

•	 presence of detectors (smoke alarms); and

•	 presence of automatic extinguishing systems.

Analyses on any of these variables that do not restrict the structure type appropriately are not valid. These same 

considerations apply to residential and nonresidential buildings below.

The one caveat is that confined structure fire incidents that do not have a structure type specified (STRUC_

TYPE is null) are presumed to occur in buildings. These incidents, however, are not included in the analyses of 

the above named variables.

The following parameters provide the total number of NFIRS 5.0 building fires. Note that this category also 

includes confined fires (INC_TYPE 113–118), which may not always occur in a building. Also note that different 

structure type parameters apply to confined and nonconfined fire incidents:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

111, 112, 120–123 (pre-2008)

Basic Incident INC_TYPE Type of incident (nonconfined fires) 111, 120–123 (from 2008 on)

AND

Fire Incident STRUC_TYPE Type of Structure 1, 2

Basic Incident INC_TYPE Type of incident (confined fires) 113–118 

AND

Fire Incident STRUC_TYPE Type of Structure 1, 2, or NULL
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 17

ANALYSIS OF NFIRS 5.0 DATA

In previous versions of NFIRS, the term “structure” commonly referred to buildings where people live and 

work. To coincide with this concept, the definition of a building fire for NFIRS 5.0 has, therefore, changed to 

include only those fires where the NFIRS 5.0 Structure Type is 1 or 2 (enclosed building and fixed portable or 

mobile structure). Such fires are referred to as “buildings” to distinguish these buildings from other structures 

that may include fences, sheds, and other uninhabitable structures. In addition, confined fire incidents that 

do not have a structure type specified (STRUC_TYPE is null) are presumed to occur in buildings. Nonconfined fire incidents without a structure type specified are considered to be invalid incidents (structure type is 

a required field) and are not included in analyses of building fires. See the next sections on Confined Building Fires

and Nonconfined Building Fires.

Starting with 2008 NFIRS data, the definition of Incident Type 112 was enforced. Early analyses of Incident 

Type 112 (fire in structure, other than in a building) indicated that these incidents were often miscoded and 

were intended to be building fires. As a result, prior to 2008, Incident Type (INC_TYPE) 112 is included as a 

building fire; from 2008 on, it is excluded.

Confined Building Fires

The following parameters provide the number of NFIRS 5.0 confined building fires:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 113–118 

AND

Fire Incident STRUC_TYPE Type of Structure 1, 2, or NULL

Nonconfined Building Fires

The following parameters provide the number of NFIRS 5.0 nonconfined building fires:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

111, 112, 120–123 (pre-2008)

Basic Incident INC_TYPE Type of incident 111, 120–123 (from 2008 on)

AND

Fire Incident STRUC_TYPE Type of Structure 1, 2

Below is an example of a distribution of confined and nonconfined building fires.

Residential Building Smoking-Related Fires by Type of Incident (2006–2008) 

Incident Type Percent

Nonconfined fires 94.2

Confined fires 5.8

Trash or rubbish fire, contained 5.4

Cooking fire, confined to container 0.2

Commercial compactor fire, confined to rubbish 0.1

Total 100.0

Source: NFIRS 5.0.

Note: It is rare that confined smoking-related fires are associated with cooking and heating. Ninety-three percent of the confined smoking-related fires 

are from fires in trash or garbage bins.
18 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Type of Fire by Property Use

The general categories of property use are shown in the following table. Residential properties are defined 

by including only the 400 series. Nonresidential, or more properly “not residential,” properties are defined 

by excluding the 400 series. This exclusion generally means that unknown or blank entries in property use 

will automatically be considered nonresidential. Property use is a required field; blank and null values are not 

expected (but do occur). Null values in property use receive special treatment as the requirements for certain 

types of incidents changed in 2006 and the specifications are discussed in a later section, Nonresidential Fires.

Property Use Property Use Code

Assembly 100 series (if Eating/Drinking separate, less 160 series)

Eating, drinking places 160 series

Educational 200 series

Health care, detention, and correction 300 series

Residential 400 series

1 or 2 family dwelling 419

Multifamily dwelling 429

Other residential 400, 439, 449, 459, 460, 462, 464 or 400, 439–499

Mercantile, business 500 series

Industrial, utility, defense, agriculture, mining 600 series

Manufacturing, processing 700 series

Storage 800 series (if Residential Garage separate, less 881)

Detached residential garage 881

Outside or special property 900 series

Property use, other 000–009

None NNN

Undetermined UUU

Property Use Issues

Prior to January 2006, PROP_USE was not required when AID was 3, 4, or 5. Since then, PROP_USE is required 

for AID = 5.4

The mixed use property variable, while available, has not been used by USFA in analyses to date. It is anticipated that analytic issues may be encountered with this data element.

Residential Fires

All incidents that relate to property used for residential purposes will have a property use (PROP_USE) code 

in the 400–499 range. The following parameters provide the total number of residential property fires in the 

NFIRS database by including the residential property use range:

4 As an aside, for analysts who include the NFIRS 4.1 converted data, the 4.1 conversion to 5.0 may have yielded null or blank values in PROP_

USE when 4.1 was blank or coded as “???”.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 19

ANALYSIS OF NFIRS 5.0 DATA

Residential Property Fires

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 100–109, 111–199

Basic Incident PROP_USE Property use 400–499

Residential Structure Fires

The following parameters provide the total number of NFIRS 5.0 residential structure fires in the database by 

including the property use range of residential properties:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 111–123

Basic Incident PROP_USE Property use 400–499

Residential Building Fires

The following parameters provide the total number of NFIRS 5.0 residential building fires in the database by 

including the property use range of residential properties and enclosed structures:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

111, 112, 120–123 (pre-2008)

Basic Incident INC_TYPE Type of incident 111, 120–123 (from 2008 on)

AND

Fire Incident STRUC_TYPE Type of structure (enclosed ....) 1, 2

Basic Incident INC_TYPE Type of incident 113–118 

AND

Fire Incident STRUC_TYPE Type of structure (enclosed ....) 1, 2, or NULL

Basic Incident PROP_USE Property use 400–499

Nonresidential Fires

All incidents that relate to property used for other than residential purposes—‘nonresidential’ properties—are 

specified by excluding the residential property use codes (PROP_USE) in the 400 to 499 range. Null values in 

property use are included or excluded according to the following rubric:

Prior to 2006, if PROP_USE is NULL and not (400-499), then the incident is “not residential;” from 2006 

on, incidents with NULL property use are excluded.

The following parameters provide the total number of nonresidential fires in the NFIRS database by excluding

the property use range of residential properties:
20 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Nonresidential Property Fires

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 100–109, 111–199

Basic Incident PROP_USE Property use NOT 400–499 or is NULL (pre-2006)

NOT 400–499 or NOT NULL (from 2006 on)

Nonresidential Structure Fires

The following parameters provide the total number of NFIRS 5.0 nonresidential structure fires in the database 

by excluding the property use range of residential properties:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 111–123

Basic Incident PROP_USE Property use NOT 400–499 or is NULL (pre-2006)

NOT 400–499 or NOT NULL (from 2006 on)

Nonresidential Building Fires

The following parameters provide the total number of NFIRS 5.0 nonresidential building fires in the NFIRS 

database by excluding the property use range of residential properties and including only enclosed structures:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

111, 112, 120–123 (pre-2008)

Basic Incident INC_TYPE Type of incident 111, 120–123 (from 2008 on)

AND

Fire Incident STRUC_TYPE Type of structure (enclosed ....) 1, 2

Basic Incident INC_TYPE Type of incident 113–118 

AND

Fire Incident STRUC_TYPE Type of structure (enclosed ....) 1, 2, or NULL

Basic Incident PROP_USE Property use NOT 400–499 or is NULL (pre-2006)

NOT 400–499 or NOT NULL (from 2006 on)

Other Property Definitions

Manufactured Homes

Mobile structures, referred to as Manufactured Homes, are defined as Incident Types between 120 and 123 

and property use in the 400 series. This definition may be overly inclusive (see table below) but analyses of 

the NFIRS data reveal that many incidents having 120, 122, and 123 Incident Types (INC_TYPE) were coded as 

residential properties, implying that the incidents were mobile homes. 
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 21

ANALYSIS OF NFIRS 5.0 DATA

Mobile Structure Incident Type Description

120 Fire in mobile property used as a fixed structure, other

121 Fire in mobile home used as fixed residence

122 Fire in motor home, camper, recreational vehicle

123 Fire in portable building, fixed location

In NFIRS, manufactured homes are defined as mobile homes used as fixed residences. Manufactured homes are 

typically residential trailers, although the distinction between residential trailers and other prefabricated homes 

is not as clear as in previous NFIRS versions. In most queries, structures are broadly defined as INC_TYPE 

111–123, which include a wide range of buildings and mobile structures, including parked trailers and recreational vehicles. A more strict definition is required to focus on those mobile residential structures that closely 

approximate manufactured homes. 

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 120–123

Basic Incident PROP_USE Property use 400–499

Fire Incident STRUC_TYPE Type of structure (enclosed only) 1, 2 

Vacant/Under Construction Buildings, Nonconfined Fires

Vacant/under construction buildings can be involved in any type of nonconfined fire incident and are defined 

by the building status field located on the Structure Fire Module. The key criteria are to include STRUC_STAT 

= 1 or 4–7, which are vacant or under construction codes. The overall parameters that are used to analyze vacant or under construction properties are below. Residential or nonresidential property use can also be specified (not shown below).

Note that vacant/under construction buildings are analyzed for nonconfined fires only because the building 

status is not a required field for confined fires.

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 111, 112, 120–123 (pre-2008)

111, 120–123 (from 2008 on)

Fire Incident STRUC_TYPE Type of structure (enclosed only) 1, 2 

Fire Incident STRUC_STAT Building status 1 or 4–7

Occupied Buildings, Nonconfined Fires

Building status is also used in analyses of alerting systems (typically smoke alarms) and less often in the analyses of suppression systems (sprinklers). For analyses of alarm effectiveness, one of the key issues is whether the 

alarm was effective at alerting the occupants. This analyses is done for occupied buildings only (STRUC_STAT 

= 2). Analyses have demonstrated that “not actively occupied housing” (vacant or under construction) typically do not include sufficient data in the smoke alarm variables; by only analyzing occupied buildings—where 

alarm systems are designed to alert occupants—undetermined and null entries are reduced. The overall pa-
22 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

rameters that are used to analyze nonconfined fires in occupied buildings are below. Residential or nonresidential property use can also be specified (not shown below). However, there are some exceptions to analyzing 

smoke alarm data for nonconfined fires in occupied buildings only for certain property types (e.g., multifamily 

buildings and university housing). For these residential property types, smoke alarm analyses should include 

both occupied and unoccupied buildings because of alarm placement, possible interconnection of alarms in new 

construction, stricter building codes, and the proximity or closeness of the dwelling units/living quarters 

that may allow occupants to hear an alarm, smell smoke, or see flames coming from a neighboring unit. Even 

though a fire may start in an unoccupied unit, it is possible that a fire department will be notified either automatically or by an occupant in a neighboring unit.

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Basic Incident INC_TYPE Type of incident 111, 112, 120–123 (pre-2008)

111, 120–123 (from 2008 on)

Fire Incident STRUC_TYPE Type of structure (enclosed only) 1, 2 

Fire Incident STRUC_STAT Building status 2

Casualties

When analyzing casualties, the basic incident file or the casualty files can be used. These files, however, produce different results because the tallies in the basic incident file may include EMS casualties that occur at the 

incident (see the sections above on Casualty Considerations). In the case of firefighter casualties, the tallies in the 

basic incident file also include exposure reports that in themselves are not injuries. 

Civilian Casualties

Below are the basic parameters that are used to analyze civilian fire injuries and deaths. It is important to note 

that since a large number of civilian injuries and deaths occur in residential structures, specifically buildings, 

these incidents are typically analyzed. The parameters for residential buildings (and other groupings) are discussed earlier. These parameters would be included with injury parameters below for analyses of fire casualties 

in the various property or incident types.

Civilian Fire Injuries (from Civilian Fire Casualty Module)

The following parameters are used to analyze civilian injuries: 

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Civilian Fire Casualty SEV Severity of incident NOT 5 or is NOT NULL

Civilian Fire Deaths

The following parameters are used to analyze civilian fire deaths:

Table Field Description Value

Basic Incident VERSION Specifies NFIRS version ‘5.0’

Basic Incident AID Aid provided between departments NOT 3–4

Civilian Fire Casualty SEV Severity of incident 5
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 23

ANALYSIS OF NFIRS 5.0 DATA

Firefighter Casualties

When analyzing casualties, the basic incident file or firefighter casualty file can be used. Both files, however, 

produce different results. This is because the basic incident file firefighter casualty fields (i.e., FF_DEATH and 

FF_INJ) include a large number of casualties from the EMS casualty file. In order to help eliminate the presence of the EMS casualties, the firefighter casualty file should be used. It is important to note, however, that 

some EMS casualties may still be counted as firefighter casualties even in the firefighter casualty file. 

EMS casualties are present in the basic incident and firefighter casualty files because some incidents include 

both EMS and firefighter casualties. To help avoid having EMS casualty counts included in firefighter casualty 

counts, it may be necessary to include in the query: firefighter injuries (FF_INJ) are greater than zero or firefighter deaths (FF_DEATH) are greater than zero. By including this clause, the EMS casualties will be excluded 

from firefighter casualties.

Firefighter Injuries

The following parameters are used to analyze firefighter injuries: 

Table Field Description Value

Firefighter Casualty

Firefighter Casualty

Basic Incident

VERSION

SEVERITY

FF_INJ

Specifies NFIRS version

Severity of incident

Count of firefighter injuries

‘5.0’

NULL or NOT 1, 7 (pre-2005)

NOT 1, 7 or NOT NULL (from 2005 on)

> 0

Firefighter Deaths

The following parameters are used to analyze firefighter deaths:

Table Field Description Value

Firefighter Casualty VERSION Specifies NFIRS version ‘5.0’

Firefighter Casualty SEVERITY Severity of incident 7

Basic Incident FF_DEATH Count of firefighter deaths > 0

Issues involving the firefighter casualty file are discussed in the section Casualty Considerations.

Determining Cause

Since the introduction of NFIRS Version 5.0, the implementation of the cause hierarchy has resulted in a steady 

increase in the percentages of unknown fire causes. This increase may be due, in part, to the fact that the 

original cause hierarchy (described in Fire in the United States 1995–2004, 14th ed.) does not apply as well to Version 5.0. Causal information now collected as part of NFIRS Version 5.0 was not incorporated in the old hierarchy. As a result, many incidents were assigned to the unknown cause category. As the hierarchy was originally 

designed for structures, incidents that did not fit well into the structure fire cause categories (e.g., vehicles and 

outside fires) were also assigned to the unknown cause category. 

Structure Fires

To capture the wealth of data available in NFIRS 5.0, USFA developed a modified version of the previous cause 

hierarchy for structure fires as shown in the Three-Level Structure Fire Cause Hierarchy table that follows. The revised 

schema provides three levels of cause descriptions: a set of more detailed causes (priority cause description), a 

set of mid-level causes (cause description), and a set of high-level causes (general cause description). The prior-
24 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

ity cause description and the cause description existed previously as part of the original cause hierarchy, but 

have been expanded to capture the new 5.0 data. 

The causes of fires are often a complex chain of events. To make it easier to grasp the “big picture,” the 16 

mid-level categories of fire causes such as heating, cooking, and playing with heat source are used by the USFA 

in their reports. The alternative is to present scores of detailed cause categories or scenarios, each of which 

would have a relatively small percentage of fires. For example, heating includes subcategories such as misuse of 

portable space heaters, wood stove chimney fires, and fires involving gas central heating systems. Experience 

has shown that the larger mid-level categories are useful for an initial presentation of the fire problem. A more 

detailed analysis can follow.

Fires are assigned to one of the 16 mid-level cause groupings using a hierarchy of definitions, approximately 

as shown in the Mid-Level Structure Fire Cause Hierarchy in Hierarchical Order table that follows. A fire is included in the 

highest category into which it fits on the list. If it does not fit the top category, then the second one is considered, and if not that one, the third, and so on. Once a match is found, the cause is assigned and no further 

checking of subsequent categories is done in the matrix. (See Three-Level Structure Fire Cause Hierarchy table note for 

an example.)
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 25

ANALYSIS OF NFIRS 5.0 DATA

Three-Level Structure Fire Cause Hierarchy

Code Priority Cause 

Description Code Cause Description Code General Cause Description

03 Exposure 12 Exposure 06 Exposure

04 Intentional 01 Intentional 01 Firesetting

05 Children Playing 02 Playing with Heat Source 01 Firesetting

06 Natural 11 Natural 02 Natural

07 Fireworks 09 Other Heat 05 Flame, Heat

08 Explosives 09 Other Heat 05 Flame, Heat

09 Smoking 03 Smoking 05 Flame, Heat

11 Heating 04 Heating 03 Equipment

12 Cooking 05 Cooking 03 Equipment

13 Air Conditioning 07 Appliances 03 Equipment

14 Electrical Distribution 06 Electrical Malfunction 04 Electrical

15 Appliances 07 Appliances 03 Equipment

16 Special Equipment 10 Other Equipment 03 Equipment

17 Processing Equipment 10 Other Equipment 03 Equipment

18 Torches 08 Open Flame 05 Flame, Heat

19 Service Equipment 10 Other Equipment 03 Equipment

20 Vehicle, Engine 10 Other Equipment 03 Equipment

21 Heat Source or Product Misuse 15 Other Unintentional, Careless 07 Unknown

22 Equipment Operation Deficiency 14 Equipment Misoperation, Failure 03 Equipment

23 Equipment Failure, Malfunction 14 Equipment Misoperation, Failure 03 Equipment

24 Other Unintentional 15 Other Unintentional, Careless 07 Unknown

25 Unclassified Fuel Powered Equipment 10 Other Equipment 03 Equipment

26 Unclassified Electrical 

Malfunction 06 Electrical Malfunction 04 Electrical

27 Matches, Candles 08 Open Flame 05 Flame, Heat

28 Open Fire 08 Open Flame 05 Flame, Heat

29 Other Open Flame, Spark 09 Other Heat 05 Flame, Heat

30 Friction, Hot Material 09 Other Heat 05 Flame, Heat

31 Ember, Rekindle 08 Open Flame 05 Flame, Heat

32 Other Hot Object 09 Other Heat 05 Flame, Heat

33 Exposure 2 12 Exposure 06 Exposure

34 Unknown 13 Unknown 07 Unknown

36 Other Playing 02 Playing with Heat Source 01 Firesetting

37 Trash, Rubbish 13 Unknown 07 Unknown

38 Investigation with Arson Module 16 Investigation with Arson Module 07 Unknown

39 Unclassified Equipment with Other or 

Unknown Fuel Source 13 Unknown 07 Unknown

Note: Fires are assigned to a cause category in the hierarchical order shown. For example, if the fire is judged to be intentionally set and a match was 

used to ignite it, it is classified as intentional and not open flame because intentional is higher on the list.
26 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Mid-Level Structure Fire Cause Hierarchy in Hierarchical Order

Cause Category Definition

Exposure Caused by heat spreading from another hostile fire

Intentional Cause of ignition is intentional or fire is deliberately set

Investigation with 

Arson Module Cause is under investigation and a valid NFIRS Arson Module is present

Playing with 

Heat Source

Includes all fires caused by individuals playing with any materials contained in the categories 

below as well as fires where the factors contributing to ignition include playing with heat source; 

children playing fires are included in this category

Natural Caused by the sun’s heat, spontaneous ignition, chemicals, lightning, static discharge, high 

winds, storms, high water including floods, earthquakes, volcanic action, and animals

Other Heat Includes fireworks, explosives, flame/torch used for lighting, heat or spark from friction, molten 

material, hot material, heat from hot or smoldering objects 

Smoking Cigarettes, cigars, pipes, and heat from undetermined smoking materials 

Heating

Includes confined chimney or flue fire, fire confined to fuel burner/ boiler malfunction, central 

heating, fixed and portable local heating units, fireplaces and chimneys, furnaces, boilers, 

water heaters as source of heat

Cooking Includes confined cooking fires, stoves, ovens, fixed and portable warming units, deep fat fryers, open grills as source of heat

Appliances 

Includes televisions, radios, video equipment, phonographs, dryers, washing machines, dishwashers, garbage disposals, vacuum cleaners, hand tools, electric blankets, irons, hairdryers, 

electric razors, can openers, dehumidifiers, heat pumps, water-cooling devices, air conditioners, freezers and refrigeration equipment as source of heat

Electrical 

Malfunction

Includes electrical distribution, wiring, transformers, meter boxes, power switching gear, outlets, cords, plugs, surge protectors, electric fences, lighting fixtures, electrical arcing as source 

of heat

Other Equipment

Includes special equipment (radar, x-ray, computer, telephone, transmitters, vending machine, 

office machine, pumps, printing press, gardening tools, or agricultural equipment), processing 

equipment (furnace, kiln, other industrial machines), service, maintenance equipment (incinerator, elevator), separate motor or generator, vehicle in a structure, unspecified equipment

Open Flame, Spark 

(Heat From)

Includes torches, candles, matches, lighters, open fire, ember, ash, rekindled fire, backfire from 

internal combustion engine as source of heat

Other Unintentional, 

Careless

Includes misuse of material or product, abandoned or discarded materials or products, heat 

source too close to combustibles, other unintentional (mechanical failure/malfunction, backfire)

Equipment Misoperation, Failure Includes equipment operation deficiency, equipment malfunction

Unknown Cause of fire undetermined or not reported
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 27

ANALYSIS OF NFIRS 5.0 DATA

Using the NFIRS Cause Categories

For USFA’s analytic purposes, all structure fires in NFIRS fall into one of the 16 mid-level cause categories, 

denoted by a code:

Cause Code Cause Description

01 Intentional

02 Playing with Heat Source

03 Smoking

04 Heating

05 Cooking

06 Electrical Malfunction

07 Appliances

08 Open Flame

09 Other Heat

10 Other Equipment

11 Natural

12 Exposure

13 Unknown

14 Equipment Misoperation, Failure

15 Other Unintentional, Careless

16 Investigation with Arson Module

The cause categories include determinations of intent (intentional, investigation, playing, unintentional), accidental fires (smoking, heating, etc.), natural fires, exposure fires, and malfunction fires. The cause is not 

reported by the fire department but is interpreted from a combination of entries in the NFIRS modules. To 

maintain the cause hierarchy, there are a series of approximately 35 steps, or queries, which assign the fire 

incidents into separate priority “bins” which are aggregated to provide cause totals.

Appendix A, Hierarchical Cause Matrix, contains the current matrix of field values that determine each cause. Each 

row in the matrix represents an individual step based on its priority level in the cause hierarchy. Some causes 

have multiple steps and the steps may not be contiguous. There are two primary methods for counting incidents by cause: 

•	 Create a reporting script in a database management system (e.g., SAS or Microsoft® Sequel Server), which 

is a program that runs a series of queries based on the cause matrix. This maintains a count of each cause 

category and produces a report of the final cause totals.

•	 Create a cause field in the basic incident table or create a separate cause table with ID keys, and then run a 

series of queries based on the cause matrix to assign a cause code to each structure fire incident record.

Using either method, the incidents must be removed from consideration once they have been assigned a cause. 

One can think of the cause categories as a series of bins in which the incident records are separated. Once a set 

of records is assigned to a cause (e.g., smoking), those records are figuratively placed in the smoking bin and 

are no longer available to be assigned to any cause further down the hierarchical scale. The result of this hierarchy is that the cause categories are mutually exclusive. 

The following graphic is an example of an analysis of how fire data are assigned to the cause categories.
28 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Causes of Fatal Residential Building Fires (2006–2008)

0.0 10.0 20.0 30.0 40.0 50.0

Unknown

Investigation with Arson Module

Other Unintentional, Careless

Equipment Misoperation, Failure

Exposure

Natural

Other Equipment

Other Heat

Open Flame

Appliances

Electrical Malfunction

Cooking

Heating

Smoking

Playing with Heat Source

Intentional

Percent of Residential 

Building Fires with 

Cause Determined

Percent of All Fatal 

Residential Building Fires

10.0

5.7

2.0

1.1

18.9

10.8

6.5

3.7

4.0

2.3

10.9

6.2

1.3

0.7

8.4

4.8

7.6

4.3

1.7

1.0

0.7

0.4

0.8

0.5

3.8

14.9

8.5

8.5

4.8

2.2

43.0

Percent of Fatal Residential Building Fires

Causes

Source: NFIRS 5.0.

Note: Causes are listed in order of the USFA cause hierarchy for ease of comparison of fire causes across different aspects of the fire 

problem. Fires are assigned to one of 16-cause groupings using a hierarchy of definitions, approximately as shown in the chart 

above. A fire is included in the highest category into which it fits. If it does not fit the top category, then the second one is considered, and if not that one, the third, and so on. For example, if the fire is judged to be intentionally set and a match was used to 

ignite it, it is classified as intentional and not open flame because intentional is higher in the hierarchy.

Vehicle, Outside, and Other Fires

While these new cause categories have usefulness for the other property types—vehicle, outside, and other 

fires—there are limitations. USFA plans to investigate and develop specific cause categories for vehicle, outside, 

and other fires. Until then, the causes of fires for these property types presented in this edition are based on 

the distributions for the cause of ignition (CAUSE_IGN) data element located on the fire incident table. This 

data element captures a very broad sense of the cause of the fire.

At this time, there is no specific methodology for determining the cause of nonstructure (i.e., vehicle and outside) fires. 

Cause of Fire Versus Cause of Fire Death/Fire Injury 

There is a subtle, but important, difference in the phrases “cause of fire,” “cause of a fire that results in deaths/

injuries” (i.e., cause of fatal fires or of fires that result in injuries), and “cause of fire deaths.” The latter phrase 

is an incorrect application of the fire cause methodology to the one-to-many relationship of fire to deaths and 

injuries.

The first phrase, “cause of fire,” is a straightforward application of the NFIRS cause hierarchy to count the 

number (or determine the percent) of fires that fall into a particular category. The second phrase, “cause of 

a fire that results in deaths/injuries” is also a straightforward application of the hierarchy to count types of 

fires—this time to count only those fires where deaths or injuries result. An analysis of casualty-producing 
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 29

ANALYSIS OF NFIRS 5.0 DATA

fires is an informative analytic task that is very important to understanding the risks of specific behaviors or 

circumstances and to better identify life safety issues.

The phrase, “cause of fire deaths,” is a common but misleading measure. Analysts are too often tempted to just 

count deaths and injuries without regard to the initiating circumstance—the fire itself. No casualties, regardless of the number, can occur without the single fire event. While multiple fatality or multiple injury fires are 

very important to capture, merely counting the casualties these fires produce, while interesting, is not necessarily the best measure of loss. For instance, consider the following fictitious scenario: 100 arson fires produce 

300 deaths. The 300 deaths could be the result of say, 99 fires each with 1 death and 1 fire with 201 deaths or 

100 arson fires with 3 deaths each. Regardless, 100 fires resulted in the deaths, and it is the 100 fires that need 

to be analyzed. In the former case, the one fire with substantial deaths indicates that an out-of-the ordinary 

event occurred and merits serious attention. In the latter case, where there are 100 fires of issue, it indicates a 

consistent multiple fatality cause that needs further attention. 

Children Playing 

The NFIRS 5.0 causes, as defined by USFA, no longer address the specific cause of “children playing.” The USFA 

has opted for the overall cause of “playing with fire.” To determine, to the extent possible, if a child playing 

with a heat source (such as matches or stove top) caused the fire, the analyst will need to include the human 

factors contributing to ignition (eight separate factors) equal to seven (age was a factor) in the query criteria, 

factors contributing to ignition and other requirements. In addition, an age range or cutoff for the associated 

age variable will need to be included. The details of these criteria are noted in Appendix A, Hierarchical Cause 

Matrix where priority cause is 5. It is important to note that the priority causes cannot be taken out of context from the matrix; doing 

so will include incidents that would have been included in other priority codes based on earlier steps in the matrix. It is recommended that the 

entire cause matrix be implemented.

Smoking-Related (Smoking) Versus Smoking Materials

The term “smoking-related fires” applies to those fires that are caused by cigarettes, cigars, pipes, and heat 

from undetermined smoking materials. USFA differentiates between smoking as a cause of fires and fires ignited by smoking materials. Smoking (or smoking-related fires) is considered a behavioral cause. Fires ignited by 

smoking materials are considered as a group of fires where smoking materials were the heat source. The two 

sets are similar but not identical. A deliberately-set fire with smoking materials as the heat of ignition would 

be considered an “intentional” fire; a fire unintentionally set by someone smoking (cigarettes, cigars, or other 

smoking materials) would be considered a “smoking-related fire.”

As well, “smoking-related” or “smoking materials” is not synonymous with cigarettes. Cigarettes, however, are 

by far the leading smoking material heat source reported to NFIRS under the ‘open flame and smoking materials’ heat source category. In fact, between 2007 and 2009, cigarettes accounted for 84 percent of smoking 

material heat sources and rises to 99 percent when undetermined smoking materials are included.

A general discussion of analytic options for the distribution of “undetermined” and “other” codes can be 

found in the section, Data Elements with Grouped Code Lists.

Loss Measures

The fire death and injury rates per 1,000 fires and the total dollar loss (property and content loss) per fire are 

important metrics. Typically, when comparing these rates, USFA removes the set of incidents under investigation from the parent set, thereby removing the effect of the incidents under investigation from the comparison 

group. An example is shown below.
30 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Loss Measures for Attic and Nonattic Residential Building Fires (3-year average, 2006–2008)

Measure Attic Residential 

Building Fires

Nonattic Residential 

Building Fires

Average Loss:

Fatalities/1,000 fires 2.5 5.5

Injuries/1,000 fires 11.2 28.6

Dollar loss/fire $38,950 $15,550

Source: NFIRS 5.0.

Note: Average loss for fatalities and injuries is computed per 1,000 fires; average dollar loss is computed per fire and is rounded to the nearest $10.

As can be seen, these loss rates are considerably different. Note, however, as NFIRS is not a statistically-selected 

random sample, comparative statements should be made with caution.

Analysis of Common Data Elements

NFIRS is not a census of fires and fire losses. The results of data queries only reflect the numbers of fires and 

fire losses reported to NFIRS and not for the Nation as a whole. The analyst has two choices when presenting 

results: present the results as a percentage (preferred) or as a national estimate. The latter choice has special 

challenges and is generally not employed except to quantify the major areas of fire losses.

Deaths and Injuries

Civilian

Totals for civilian deaths or injuries can be derived by summing the values in the respective fields (OTH_

DEATH, OTH_INJ) in the basic incident table. Alternatively, the casualty records can be used to count deaths 

and injuries, noting the issues concerning EMS casualties that may be included in the casualty file. For a more 

detailed discussion, see the earlier sections, Casualty Considerations and Casualties.

Firefighter

Unlike civilian casualties, totals for firefighter injuries cannot be derived by summing the values of FF_INJ in 

the basic incident table as these totals will include hazardous exposures. To derive the number of firefighter 

injuries for a given set of fires, the firefighter casualty records must be counted using the severity criteria noted 

earlier. Total firefighter deaths can be derived by summing the values of FF_DEATH with all AID codes included. Alternatively, both deaths and injuries can be counted using the severity criteria noted earlier. Nonetheless, 

mutual-aid records must be included for complete counts of firefighter injuries or deaths. For a more detailed 

discussion, see the earlier sections, Casualty Considerations and Casualties.

Property and Contents Loss

NFIRS 5.0 distinguishes between “content” and “property” loss. Content loss includes loss to the contents of a 

structure due to damage by fire, smoke, water, and overhaul. Property loss includes losses to the structure itself 

or to the property itself. Both content and property loss can be found in the Basic Module. 

Total loss is the sum of the content loss and the property loss. Analysts are cautioned to be careful adding null 

values to nonnull values as the results can be unexpected—another reason to investigate how the chosen database or analytic tool handles null values.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 31

ANALYSIS OF NFIRS 5.0 DATA

For confined fires, the expectation is that the fire did not spread beyond the container (or rubbish for Incident 

Type 118) and hence, there was no property damage (damage to the structure itself) from the flames. There 

could be, however, property damage as a result of smoke, water, and overhaul.

Time of Alarm

For analytic purposes, the time of the fire alarm (ALARM) is used as an approximation for the general time 

the fire started. However, in NFIRS, it is the time the fire was reported to the fire department. Analyzing the 

time of alarm data is important because it provides information on when certain types of fires are occurring. A 

large amount of information can be obtained by looking at the peak hours when specific types of fires occur.

Month and Day

Numeric to date-time conversion may be necessary. Day of year analyses may reveal specific dates that may or 

may not be significant, depending on whether large-loss incidents are reflected or not. Certain types of fires 

are more common on certain days of the year or in certain months (e.g., the average number of reported residential building fires on Thanksgiving Day is nearly double that of those on all other days). By analyzing daily 

or monthly data, trends can be observed. Additional fire information can also be generated for these peak days 

or months. This information can provide the analyst with further insight on a specific fire problem. 

Time, Month, and Day of Death or Injury

For deaths and injuries, the date-time analyses are based on the INC_DATE information from the casualty files. 

For month and day analyses, there may be valid reasons to use the ALARM data (the date-time data for the incident itself) rather than the casualty data. The same issues with the data and conversions noted above apply. Note 

that the time of the incident and the time of the casualty (INJ_DT_TIM) will not (or may not) be the same.

Day of Week

To determine the day of week (e.g., Monday), the analyst may need to use a built-in function in the database 

system or use an existing function from the analytic tool (e.g., spreadsheet or SAS). The INC_DATE or ALARM 

data may need to be converted to the format required by the function chosen. If the incident timing crosses 

dates (i.e., straddles midnight), the analyst may need to make appropriate calculations to account for the time 

differential.

Elapsed (Response) Time

Typically, this type of analysis is used for “response times” analyses. If no arrival time (ARRIVAL) is included 

or if the calculated response time appears to exceed 24 hours, the incident should be excluded. Incidents 

classified as automatic or mutual aid (AID = 3 or 4) should also be excluded to avoid double counting of aid 

incidents. Elapsed times are generally grouped in 30-second or 1-minute intervals.

Several caveats need to be kept in mind with respect to analyses of response times. First, they are subject to 

a variety of measurement errors when units report their arrival on scene prematurely or belatedly. Second, 

response times are frequently not comparable across fire-rescue systems because of the differing manners in 

which they are calculated. Also, it is difficult, if not impossible, to measure some components of response 

time. As well, care should be taken to accurately account for response times when an alarm time (ALARM) is 

very close to midnight and the arrival time (ARRIVAL) will necessarily be the next day. As both alarm and arrival time are specified as MMDDYYYYhhmm, the analyst should remember to include the day as well as the 

time in calculating response times.
32 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

Response times are measured from alarm time to arrival on scene, but there is uncertainty in the data. NFIRS 

5.0 defines alarm time as “when the alarm was received by the fire department.” This definition is vague and 

subjective. Some departments may read this definition to mean when the notification comes into the 9-1-1 communications center (9-1-1 activation) while others may read it as when the notification comes into the station 

(dispatch time). Thus, depending on the interpretation by the department, the times reported to NFIRS may or 

may not include call processing and dispatch time, which could typically take between 30 and 120 seconds.

Equipment Involved in Ignition

In a small group of incidents, equipment involved in ignition (EQUIP_INV) is coded as “none involved” 

(NNN or nnn) but the heat source (HEAT_SOURC) is coded as operating equipment (heat source is 10-13). If 

this occurs, these incidents are recoded as “undetermined” (UUU) in analyses of equipment involved.

Fire Spread

By definition, any confined fire (INC_TYPE 113 to 118) is confined to the object of origin. In terms of fire 

spread, this is equivalent to FIRE_SPRD = ‘1.’ Some confined fires also have completed Fire Modules and have a 

record in the fire incident table (and may, unfortunately, have values other than FIRE_SPRD = ‘1’ in data prior 

to 2006). Therefore, when doing analyses on fire spread that include the confined fire incident types, it is important to segregate those confined fires without a record in the fire incident table and count them as having 

FIRE_SPRD = ‘1.’ The assumption cannot be made that, since FIRE_SPRD is a required variable, all null values 

result from confined fires and are actually “confined to object of origin.” FIRE_SPRD is only required in the Fire 

Module when STRUC_TYPE is a “1” or a “2” (enclosed building or fixed portable or mobile structure) and the 

Structure Fire Module is called into play. As a result, there will be some “legitimate” null values.

Further, an error was found in the FIRE_SPRD variable for building fires. In the case where the data years 

are prior to 2006 and the “Confined to Origin” (CONF_ORIG) checkbox is set to a value of 1 on data entry, a 

value of 1 is also to be inserted into the fire spread (FIRE_SPRD) field. Instead, the USFA software mistakenly 

inserts a null value into the FIRE_SPRD field rather than a 1. This null value is not critical because the “1” 

value still exists in the CONF_ORIG field in the fire incident table. USFA corrected this issue in the 2006 and 

subsequent data. For prior years of data, there is a choice of a data correction or a workaround.

Workaround:

1. When doing analyses for fires confined to the object of origin, check for a value of “1” in the CONF_

ORIG field rather than checking for a “1” in the FIRE_SPRD field (in the fire incident table).

Data Correction/Update:

2. Replace the NULL FIRE_SPRD values in the table with “1.” To do so, run a simple script/procedure against 

the fire incident table that says (pseudo code follows):

if INC_TYPE between 113 and 118

and STRUC_TYPE = “1” OR “2” OR NULL

and CONF_ORIG = “1”

replace FIRE_SPRD with “1”

Data Elements with Grouped Code Lists

In most of the data elements with long code lists, regardless of the module, the codes are generally organized 

into major categories or groups of like items. When analyzing the resulting distributions, the analyst should 

consider both the leading category or group and the major individual code. Incident type and property use 

(discussed earlier) are also examples of these types of variables.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 33

ANALYSIS OF NFIRS 5.0 DATA

Primary data elements which follow this general pattern are

Field Description Table

INC_TYPE Incident Type Basic Incident

PROP_USE Property Use Basic Incident

AREA_ORIG Area of Fire Origin Fire Incident

HEAT_SOURC Heat Source Fire Incident

FIRST_IGN Item First Ignited Fire Incident

TYPE_MAT Type of Material Ignited Fire Incident

EQUIP_INV Equipment Involved in Ignition Fire Incident

Unknown, blank, and null entries are generally considered unknown and are distributed across the other valid 

entries (i.e., removed from the analysis) for some of these fields. Treatment of null values in property use is 

discussed in the section Nonresidential Fires.

In the very few instances where the major category includes an intermediate “other” code that crosses group 

boundaries, analysts may elect to distribute the “other” category across the group of codes. This specifically 

applies to heat source (HEAT_SOURC) 60, “heat from other open flame or smoking materials, other.” USFA, 

however, does not follow this option for heat source 60 as USFA notes that the “other” category is for items 

not already specified in the code group. It is not an “unknown.” As such, no distributing is warranted.5

Multiple Entry Data Elements

Multiple entry data elements require the analyst to combine the distributions from each of the elements into 

one overall distribution. Unknown, null, and blank values are not considered and the analysis is performed 

“only where a factor was specified or indicated.” The denominator for the distribution is the number of incidents with at least one factor specified. As a result, the total percent distribution can (and usually does) total to 

greater than 100 percent.

The same factor value cannot be entered into more than one of the factor elements for an incident. The analyst, however, is well-served to check to ensure this and remove any duplicate values. Succeeding factors can 

only be entered if the preceding factor exists and is not N (no factor involved). Again, the analyst should confirm this. See the earlier section on Factor Fields for a more detailed discussion.

Primary data elements which follow this general pattern are

Data Element Description Table

FACT_IGN_1 to FACT_IGN_2 Factors Contributing to Ignition Fire Incident

HUM_FAC_1 to HUM_FAC_8 Human Factors Contributing to Ignition Fire Incident

FACT_INJ1 to FACT_INJ3 Factors Contributing to Injury Civilian Fire Casualty

HUM_FACT1 to HUM_FACT8 Human Factors Contributing to Injury Civilian Fire Casualty

SUP_FAC_1 to SUP_FAC_3 Fire Suppression Factors Fire Incident

5 USFA has analyzed heat source code 60 data for 2003, 2006, and 2008 using a stratified random sample of residential structure fires where the 

remarks field was completed for those incidents and where the heat source code was 60. The remarks were reviewed and then the heat source 

value was recoded to the appropriate value based on the information provided in the remarks field. The results for each year showed that the 

majority of the heat source 60 incidents should have been coded as kitchen/cooking fires (heat source 12) or chimney, flue fires (heat source 

81 or 43). Very few of the sampled incidents were recoded as cigarettes, candles, or other heat source 60 decade codes. These results showed 

that the heat source 60 code should not be distributed as an unknown among the remaining heat source 60 decade codes. USFA and others 

strongly agree that the heat source 60 code should not be treated as an unknown and, therefore, should not be distributed over the heat source 

61–69 categories.
34 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

If the factor data element also has grouped code lists, the analyst, as above, should consider both the leading 

group and the major individual code. Examples of both analyses are shown below.

Factors Contributing to Ignition for Fatal Residential Building Fires by Major Category 

(Where Factor Contributing Specified, 2006–2008)

Factor Contributing to Ignition Category Percent of Fatal Residential Fires 

(Unknowns Apportioned)

Misuse of material or product 59.3

Electrical failure, malfunction 15.1

Other factors contributing to ignition 13.2

Operational deficiency 12.0

Mechanical failure, malfunction 4.8

Fire spread or control 2.7

Design, manufacture, installation deficiency 1.4

Natural condition 1.1

Source: NFIRS 5.0.

Notes: 1) Includes only incidents where factors that contributed to the ignition of the fire were specified.

2) Multiple factors contributing to fire ignition may be noted for each incident; total will exceed 100 percent. 

Leading Factors Contributing to Ignition for Nonconfined Residential Building Smoking-Related Fires 

(Where Factor Contributing Specified, 2006–2008)

Factor Contributing to Ignition Percent of Nonconfined Residential Smoking-Related 

Fires Where Contributing Factor Specified

Abandoned or discarded materials or products 66.8

Unspecified misuse of material or product 15.2

Heat source too close to combustibles 10.9

Source: NFIRS 5.0. 

Notes: 1) Includes only incidents where factors that contributed to the ignition of the fire were specified. 

2) Multiple factors contributing to fire ignition may be noted for each incident.

Smoke Alarms 

In general, USFA presentation of the smoke alarm data in NFIRS requires a relatively straightforward approach 

by separating the available data into smoke alarm data for confined fires and for nonconfined fires. Smoke 

alarm data are collected at the fire incident level (not the casualty level). As such, USFA’s analysis of smoke 

alarm data is not directly transferable to numbers (or percentages) of deaths and injuries.

Smoke alarm data are collected via seven data elements, one in the basic incident table and six in the fire incident table. The detector alerted occupants (DET_ALERT) field, from the basic incident table, is required for 

confined structure fires (but not for nonconfined structure fires). The six other variables are required for nonconfined building fires (those structure fires with STRUC_TYPE = 1, 2) and optional for confined fires (and 

not generally reported). The smoke alarm data elements are listed in the following table:
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 35

ANALYSIS OF NFIRS 5.0 DATA

Table Field Description

Basic Incident DET_ALERT Detector Alerted Occupants

Fire Incident DETECTOR Detector Presence

Fire Incident DET_TYPE Detector Type

Fire Incident DET_POWER Detector Power

Fire Incident DET_OPERAT Detector Operation

Fire Incident DET_EFFECT Detector Effectiveness

Fire Incident DET_FAIL Detector Failure Reason

USFA has since abandoned its earlier smoke alarm analysis methodology. Detailed analyses of the data revealed 

inconsistencies in interpreting the relationships between the several data elements. These inconsistencies resulted in an overly complex analytic framework that relied on inferred relationships between the smoke alarm 

variables. Currently, USFA has opted to present the undistributed data for presence, operation, and effectiveness. Other smoke alarm variables are not analyzed at this time.

USFA analyzes the general presence of smoke alarms for all buildings. For confined fires, the variable DET_

ALERT is used. As confined fires are only required to provide the basic incident data, the analyst does not have 

the information to determine the occupancy status. For nonconfined fires, the variable DETECTOR is used. 

Because the effectiveness of smoke alarms (i.e., if the occupant heard and responded to the alarm) can only be 

measured if occupants are present, detailed analyses on the combination of presence, operation, and effectiveness of smoke alarms are generally undertaken for nonconfined fires in occupied buildings only. There are 

exceptions to this general rule, such as in analyses of buildings with multiple occupancies where some occupancies may be in use and others may be vacant, e.g., multifamily buildings.

Note: USFA does not distribute unknowns in its presentation of smoke alarm data.

Smoke Alarms in Confined Fires

The detector alerted occupants (DET_ALERT) data from the basic incident table are only used in the analysis 

of smoke alarms in confined structure fires and are used to determine solely whether the alarm alerted the occupant. USFA presents smoke alarm data for confined structure fires that are defined as building fires. 

Note: Structure type (STRUC_TYPE), the data element that is used to determine whether a structure is a building, is not required for confined fires. As such, confined fires with no structure type reported are assumed to 

be building fires.

Note: If the occupant was not alerted by a smoke alarm, the analyst will not know whether the lack of notification was because:

•	 no alarm was in the vicinity;

•	 the alarm did not operate (for whatever reason, including fire too small);

•	 the smoke alarm was present and operated but the occupant was already aware of the fire; or 

•	 no occupants were present at the time of the fire.

A typical analysis (with data source attribution and analysis notes) is shown in the following table.
36 NFIRS 5.0 Fire Data Analysis Guidelines and Issues

ANALYSIS OF NFIRS 5.0 DATA

NFIRS Smoke Alarm Data for Confined Multifamily Residential Building Fires (2005–2007)

Smoke Alarm Effectiveness Count Percent

Smoke alarm alerted occupants 61,555 46.7

Smoke alarm did not alert occupants 19,620 14.9

Unknown 50,656 38.4

Total Incidents 131,831 100.0

Source: NFIRS 5.0.

Notes: The data presented in this table are raw data counts from the NFIRS data set. They do not represent national estimates of smoke alarms in confined multifamily residential building fires. They are presented for informational purposes. 

Smoke Alarms in Nonconfined Fires

For nonconfined fires, the data elements detector presence (DETECTOR), detector operation (DET_OPERAT), and 

detector effectiveness (DET_EFFECT) from the fire incident table are combined to present the full range of smoke 

alarm performance and effectiveness in alerting occupants. As these data elements are only required for building 

fires and other enclosed structures (logically, where one would expect smoke alarms to be located), only smoke 

alarm presence, operation, and effectiveness in building fires are presented. Typically, the presence of smoke 

alarms is presented as a stand-alone distribution then combined with the other two variables to present the full 

range of smoke alarm performance and effectiveness in nonconfined fires. Examples are shown below.

Presence of Smoke Alarms in Fatal Residential Building Fires (2006–2008)

Presence of Smoke Alarms Percent

Present 37.7

None present 22.5

Undetermined 39.7

Null/Blank <0.1

Source: NFIRS 5.0.

Note: Total may not add to 100 percent due to rounding.

NFIRS Smoke Alarm Data for Fatal Residential Building Fires in Occupied Housing (NFIRS, 2006–2008)

Presence of 

Smoke Alarms Smoke Alarm Operational Status Smoke Alarm Effectiveness Count Percent

Present

Fire too small to activate smoke alarm 9 0.3

Smoke alarm operated

Smoke alarm alerted occupants, 

occupants responded 209 6.5

Smoke alarm alerted occupants, 

occupants failed to respond 83 2.6

No occupants 1 0.0

Smoke alarm failed to alert occupants 28 0.9

Undetermined 147 4.6

Smoke alarm failed to operate 266 8.3

Undetermined 474 14.8

None present 706 22.1

Undetermined 1,272 39.8

Total Incidents 3,195 100.0

Source: NFIRS 5.0.

Notes: The data presented in this table are raw data counts from the NFIRS data set. They do not represent national estimates of smoke alarms in fatal 

residential building fires in occupied housing. They are presented for informational purposes. Total will not add to 100 percent due to rounding.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues 37

ANALYSIS OF NFIRS 5.0 DATA

Automatic Extinguishing Systems 

Like smoke alarm data, Automatic Extinguishing Systems (AES) data are collected by multiple data elements. 

The data elements are shown in the table below:

Table Field Description

Fire Incident AES_PRES AES Presence

Fire Incident AES_TYPE AES Type

Fire Incident AES_OPER AES Operation

Fire Incident NO_SPR_OP Number of Sprinklers Operating

Fire Incident AES_FAIL AES Failure Reason

As noted above, many fires in NFIRS 5.0 are confined fires without matching fire incident records. While 

smoke alarms have a data element in the Basic Module that captures some additional alarm data, AES/Sprinkler 

data are entirely captured in the fire incident table. To remove the bias that can be introduced by the lack of 

data from confined fires (INC_TYPE between 113 to 118), only nonconfined fires are included in analyses, that 

is, confined fires have been removed from the query.

At this time, USFA analyzes only the presence of AES.

Note: USFA does not distribute unknowns in its analyses of AES data.

Additional research is necessary on the AES data to further develop appropriate methodologies, as is the ongoing case with the smoke alarm data. The following table shows an example of an analysis of AES data.

NFIRS Automatic Extinguishing System (AES) Data for Vacant Residential Building Fires (2006–2008)

Presence of Automatic 

Extinguishing Systems Count Percent

AES present 474 1.0

Partial system present 32 0.1

AES not present 42,600 90.2

Unknown 4,120 8.7

Total Incidents 47,226 100.0

Source: NFIRS 5.0.

Notes: The data presented in this table are raw data counts from the NFIRS data set. They do not represent national estimates of AESs in vacant residential building fires. They are presented for informational purposes. 
NFIRS 5.0 Fire Data Analysis Guidelines and Issues A-1

APPENDIX A: HIERARCHICAL CAUSE MATRIX

APPENDIX A: HIERARCHICAL CAUSE MATRIX (REVISED – SEPTEMBER 2015)

Order 

# Cause Description Cause Code Priority Cause Description Priority Cause Code Matrix Code Category Logic Comments

1 Exposure 12 Exposure 03 aid NOT BETWEEN ‘3’ AND ‘4’ AND exp_no != 0

2

Intentional 01

Intentional 04 aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND cause_ign = ‘1’ Former Incendiary/Suspicious category now split into two categories: 

Intentional and Cause Under Investigation (formerly called Investigation with Arson Module). Arson Module criteria for selection is Case 

Status between 1 and 5.

3 Intentional Wildland 04 aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND fire_cause = ‘7’

4 Cause Under Investigation 16 Cause Under Investigation 38

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND cause_ign = ‘5’

AND case_stat BETWEEN ‘1’ AND ‘5’

5

Playing with Heat Source 02 Children Playing 05

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 

AND( (fact_ign_1 = ‘19’ OR fact_ign_2 = ‘19’) OR cause_ign = ‘2’ )

AND age_a BETWEEN 1 AND 9 

AND (hum_fac_1 = ‘7’ OR

 hum_fac_2 = ‘7’ OR

 hum_fac_3 = ‘7’ OR

 hum_fac_4 = ‘7’ OR

 hum_fac_5 = ‘7’ OR

 hum_fac_6 = ‘7’ OR

 hum_fac_7 = ‘7’ OR

 hum_fac_8 = ‘7’)

Children Playing now combined with new ‘other playing’ category. 

Can still get ‘children playing’ from Priority Cause Code (PCC) code. 

Removed allowance of any age in first checked category.

6

7

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND fire_cause = ‘8’ 

AND age_b BETWEEN 1 AND 9

Check for children involved in setting wildland fire.

Playing with Heat Source 02 Other Playing 36

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 

AND (fact_ign_1 = ‘19’ OR fact_ign_2 = ‘19’)

Other playing added as new PCC category. Included in cause 02.

8 Natural 11 Natural 06

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 

AND (heat_sourc BETWEEN ‘70’ AND ‘74’

OR cause_ign = ‘4’ 

OR fact_ign_1 = ‘65’ OR fact_ign_2 = ‘65’)

Combined with the new ‘natural’ matrix check below.

9

Other heat 09

Fireworks 07 aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND heat_sourc = ‘54’

10 Explosives 08

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 

AND (heat_sourc BETWEEN ‘50’ AND ‘53’ 

OR heat_sourc BETWEEN ‘55’ AND ‘59’)

11 Smoking 03 Smoking 09

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 

AND heat_sourc BETWEEN ‘61’ AND ‘63’
NFIRS 5.0 Fire Data Analysis Guidelines and Issues A-2

APPENDIX A: HIERARCHICAL CAUSE MATRIX

Order 

# Cause Description Cause Code Priority Cause Description Priority 

Cause Code Matrix Code Category Logic Comments

12

Heating 04 Heating 11

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND inc_type != ‘113’ AND first_ign != ‘76’ AND equip_inv BETWEEN ‘123’ AND ‘124’

Exclude confined cooking fires. Exclude stove/insert fires where item 

first ignited is food.

13

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND (inc_type = ‘114’ OR inc_type = ‘116’) 

OR ((equip_inv = ‘100’ OR equip_inv BETWEEN ‘120’ AND ‘122’ OR equip_inv BETWEEN 

‘125’ AND ‘152’) 

AND inc_type != ‘113’)

Cooking 05 Cooking 12

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (inc_type = ‘113’ 

OR equip_inv = ‘654’ 

OR equip_inv BETWEEN ‘630’ AND ‘649’

OR (first_ign = ‘76’ AND equip_inv BETWEEN ‘123’ AND ‘124’))

Include stoves, inserts where item first ignited is food. Also includes 

confined food on stove fires.

14 Appliances 07 Air Conditioning 13

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (equip_inv = ‘445’ 

OR equip_inv = ‘652’ OR equip_inv = ‘655’

OR equip_inv = ‘656’

OR equip_inv BETWEEN ‘111’ AND ‘117’)

15 Electrical Malfunction 06 Electrical Distribution 14

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (fact_ign_1 = ‘37’ OR fact_ign_2 = ‘37’

OR equip_inv BETWEEN ‘200’ AND ‘223’

OR equip_inv BETWEEN ‘226’ AND ‘227’

OR equip_inv BETWEEN ‘230’ AND ‘299’)

Category now combined with Unclassified Electrical Malfunction.

16 Appliances 07 Appliances 15

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (equip_inv BETWEEN ‘310’ AND ‘316’

OR equip_inv BETWEEN ‘318’ AND ‘319’

OR equip_inv = ‘345’ 

 OR equip_inv = ‘600’

OR equip_inv BETWEEN ‘611’ AND ‘612’

OR equip_inv BETWEEN ‘621’ AND ‘623’

OR equip_inv = ‘651’

OR equip_inv = ‘653’

OR equip_inv BETWEEN ‘730’ AND ‘759’

OR equip_inv = ‘800’

OR equip_inv BETWEEN ‘810’ AND ‘869’

OR equip_inv = ‘871’

OR (equip_inv = ‘872’

AND NOT eq_power BETWEEN ‘20’ AND ‘39’)

OR equip_inv BETWEEN ‘874’ AND ‘876’

OR equip_inv BETWEEN ‘881’ AND ‘883’

OR equip_inv BETWEEN ‘891’ AND ‘897’)
NFIRS 5.0 Fire Data Analysis Guidelines and Issues A-3

APPENDIX A: HIERARCHICAL CAUSE MATRIX

Order 

# Cause Description Cause Code Priority Cause Description Priority 

Cause Code Matrix Code Category Logic Comments

17

Other Equipment 10

Special Equipment 16

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 AND (inc_type = ‘115’ OR inc_type = ‘117’)

AND ((fact_ign_1 IS NULL AND fact_ign_2 IS NULL)

OR (LEFT(fact_ign_1,1) != ‘1’

AND LEFT(fact_ign_2,1) != ‘1’

AND LEFT(fact_ign_1,1) != ‘2’

AND LEFT(fact_ign_2,1) != ‘2’

AND LEFT(fact_ign_1,1) != ‘5’

AND LEFT(fact_ign_2,1) != ‘5’))

Category now includes PCC 25 (Unclassified Fuel Powered Equipment). Includes priority check for following ‘factors contributing’ 

causes.

18 Special Equipment 16

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (equip_inv = ‘224’

OR equip_inv BETWEEN ‘340’ AND ‘344’

OR equip_inv BETWEEN ‘346’ AND ‘349’

OR equip_inv = ‘361’

OR equip_inv BETWEEN ‘372’ AND ‘374’

OR equip_inv BETWEEN ‘376’ AND ‘377’

OR equip_inv = ‘400’

OR equip_inv BETWEEN ‘410’ AND ‘429’

OR equip_inv BETWEEN ‘431’ AND ‘432’

OR equip_inv BETWEEN ‘440’ AND ‘444’

OR equip_inv BETWEEN ‘446’ AND ‘451’

OR equip_inv BETWEEN ‘500’ AND ‘599’

OR equip_inv BETWEEN ‘700’ AND ‘729’)

AND LEFT(fact_ign_1,1) != ‘1’

AND LEFT(fact_ign_2,1) != ‘1’

AND LEFT(fact_ign_1,1) != ‘2’

AND LEFT(fact_ign_2,1) != ‘2’

AND LEFT(fact_ign_1,1) != ‘5’

AND LEFT(fact_ign_2,1) != ‘5’

19 Processing Equipment 17

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (equip_inv = ‘300’

OR equip_inv = ‘317’

OR equip_inv BETWEEN ‘320’ AND ‘329’

OR equip_inv = ‘351’

OR equip_inv = ‘353’

OR equip_inv BETWEEN ‘355’ AND ‘358’

OR equip_inv = ‘371’)

AND LEFT(fact_ign_1,1) != ‘1’

AND LEFT(fact_ign_2,1) != ‘1’

AND LEFT(fact_ign_1,1) != ‘2’

AND LEFT(fact_ign_2,1) != ‘2’

AND LEFT(fact_ign_1,1) != ‘5’

AND LEFT(fact_ign_2,1) != ‘5’;
NFIRS 5.0 Fire Data Analysis Guidelines and Issues A-4

APPENDIX A: HIERARCHICAL CAUSE MATRIX

Order 

# Cause Description Cause Code Priority Cause Description Priority 

Cause Code Matrix Code Category Logic Comments

20 Open Flame 08 Torches 18

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (fact_ign_1 = ‘13’

OR fact_ign_2 = ‘13’

OR equip_inv BETWEEN ‘331’ AND ‘334’)

21

Other Equipment 10

Service Equipment 19

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (equip_inv = ‘225’

OR equip_inv BETWEEN ‘228’ AND ‘229’

OR equip_inv = ‘352’

OR equip_inv = ‘354’

OR equip_inv BETWEEN ‘362’ AND ‘365’

OR equip_inv BETWEEN ‘433’ AND ‘434’)

AND LEFT(fact_ign_1,1) != ‘1’

AND LEFT(fact_ign_2,1) != ‘1’

AND LEFT(fact_ign_1,1) != ‘2’

AND LEFT(fact_ign_2,1) != ‘2’

AND LEFT(fact_ign_1,1) != ‘5’

AND LEFT(fact_ign_2,1) != ‘5’

See note above for PCC 25.

22 Vehicle, Engine 20

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND inc_type BETWEEN ‘110’ AND ‘129’ AND (mob_invol BETWEEN ‘2’ AND ‘3’

OR heat_sourc = ‘68’

OR equip_inv = ‘375’)

23 Unclassified Fuel Powered 

Equipment 25

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (heat_sourc BETWEEN ‘10’ AND ‘12’

AND eq_power BETWEEN ‘10’ AND ‘49’)

AND LEFT(fact_ign_1,1) != ‘1’

AND LEFT(fact_ign_2,1) != ‘1’

AND LEFT(fact_ign_1,1) != ‘2’

AND LEFT(fact_ign_2,1) != ‘2’

AND LEFT(fact_ign_1,1) != ‘5’

AND LEFT(fact_ign_2,1) != ‘5’;

24 Unknown 13 Unclassified Equipment with 

Other or Unknown Fuel Source 39

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (heat_sourc BETWEEN ‘10’ AND ‘12’

AND eq_power NOT BETWEEN ‘10’ AND ‘49’)

AND LEFT(fact_ign_1,1) != ‘1’

AND LEFT(fact_ign_2,1) != ‘1’

AND LEFT(fact_ign_1,1) != ‘2’

AND LEFT(fact_ign_2,1) != ‘2’

AND LEFT(fact_ign_1,1) != ‘5’

AND LEFT(fact_ign_2,1) != ‘5’
NFIRS 5.0 Fire Data Analysis Guidelines and Issues A-5

APPENDIX A: HIERARCHICAL CAUSE MATRIX

Order 

# Cause Description Cause Code Priority Cause Description Priority 

Cause Code Matrix Code Category Logic Comments

25 Electrical Malfunction 06 Unclassified Electrical Malfunction 26

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (heat_sourc = ‘13’

OR fact_ign_1 BETWEEN ‘30’ AND ‘36’

OR fact_ign_2 BETWEEN ‘30’ AND ‘36’

OR equip_inv = ‘200’)

PCC 26 (Unclassified Electrical Malfunction) combined into cause 

category 06.

26

Open Flame 08

Matches, Candles 27

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (heat_sourc BETWEEN ‘64’ AND ‘66’

OR (equip_inv = ‘872’ 

AND eq_power BETWEEN ‘20’ AND ‘39’)

OR equip_inv = ‘873’)

27 Open Fire 28

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND heat_sourc = ‘67’

28

Other Heat 09

Other Open Flame, Spark 29

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (heat_sourc = ‘60’

OR heat_sourc = ‘69’)

29 Fireworks 30

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND heat_sourc BETWEEN ‘41’ AND ‘42’

30 Open Flame 08 Ember, Rekindle 31

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (heat_sourc = ‘43’

OR fact_ign_1 = ‘72’

OR fact_ign_2 = ‘72’)

31 Other Heat 09 Other Hot Object 32

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND heat_sourc = ‘40’

32 Natural 11 Natural 2 06

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (LEFT(fact_ign_1,1) = ‘6’

OR LEFT(fact_ign_2,1) = ‘6’)

Additional ‘natural’ from Factors Contributing to Ignition.

33 Other Unintentional, Careless 15 Heat Source or Product Misuse 21

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (LEFT(fact_ign_1,1) = ‘1’

OR LEFT(fact_ign_2,1) = ‘1’)

New category from 10 series of Factors Contributing to Ignition.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues A-6

APPENDIX A: HIERARCHICAL CAUSE MATRIX

Order 

# Cause Description Cause Code Priority Cause Description Priority 

Cause Code Matrix Code Category Logic Comments

34

Equipment Misoperation, 

Failure 14

Equipment Operation Deficiency 22

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (LEFT(fact_ign_1,1) = ‘5’

OR LEFT(fact_ign_2,1) = ‘5’) New category, includes cause of ignition ‘failure of equipment or heat 

source’ as final pass.

35 Equipment Failure, Malfunction 23

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (LEFT(fact_ign_1,1) = ‘2’

OR LEFT(fact_ign_2,1) = ‘2’

OR cause_ign = ‘3’)

36 Unknown 13 Trash, Rubbish 37

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (inc_type = ‘118’

OR first_ign = ‘96’)

New PCC for trash related fires.

37 Other Unintentional, Careless 15 Other Unintentional 24

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (LEFT(fact_ign_1,1) = ‘2’

OR LEFT(fact_ign_2,1) = ‘2’

OR cause_ign = ‘2’)

New category, from cause of ignition ‘Unintentional’’ as final pass.

38 Exposure 12 Exposure 2 33

aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0

AND (fact_ign_1 BETWEEN ‘70’ AND ‘71’

OR fact_ign_2 BETWEEN ‘70’ AND ‘71’

OR fact_ign_1 BETWEEN ‘73’ AND ‘75’

OR fact_ign_2 BETWEEN ‘73’ AND ‘75’

OR heat_sourc BETWEEN ‘80’ AND ‘89’)

39 Unknown 13 Unknown 34 aid NOT BETWEEN ‘3’ AND ‘4’

AND exp_no = 0 Fell through the matrix with no match.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues B-1

APPENDIX B: GENERAL INCIDENT GROUPING BY INCIDENT TYPE AND PROPERTY TYPE

APPENDIX B: GENERAL INCIDENT GROUPING 

BY INCIDENT TYPE AND PROPERTY USE

Note: Nonresidential is defined by being “not residential” under the assumption that a residential structure 

will be clearly evident to the firefighter and the data collected as such. Generally speaking, if the property type 

is not specifically noted as “residential,” it is then “nonresidential.”

Incident Type All Fires Outside Vehicle Structure Residential 

Structure

Nonresidential 

Structure Other

Property Use

(PROP_USE) 400 series

not 400 series 

excludes null 

from 2006 on

Null ü*

100 ü ü

111-118 ü ü ü ü

120-123 ü ü ü ü

130s, MOB_INVOL=1, 3

ü ü

130s, MOB_

INVOL=2,N, 

NULL

ü

140s ü ü

150s ü ü

160s less 163 ü ü

163 ü ü

170-173 ü ü

101-109

Undesignated

ü

180-189 ü

190-199 ü

*Only property uses (PROP_USE) with null values prior to 2006 are collated as “Other” properties. As property use is 

required from 2006 on, property uses with a null value are considered invalid and removed from analyses.
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-1

APPENDIX C: NFIRS PDR FILE LAYOUTS

APPENDIX C: NFIRS PDR FILE LAYOUTS

In the file layout tables that follow, the key identification (ID) fields are noted in red text.

Basic Incident Table (basicincident.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 DEPT_STA Fire Department Station X 3

8 INC_TYPE Incident Type C 3

9 ADD_WILD Address on Wildland Flag X 1

10 AID Aid Given or Received C 1

11 ALARM Alarm Date and Time N 12 MMDDYYYYhhmm

12 ARRIVAL Arrival Date and Time N 12

13 INC_CONT Incident Controlled Date and Time N 12

14 LU_CLEAR Last Unit Cleared Date and Time N 12

15 SHIFT Shift X 1

16 ALARMS Alarms X 2

17 DISTRICT District X 3

18 ACT_TAK1 Actions Taken #1 C 2

19 ACT_TAK2 Actions Taken #2 C 2

20 ACT_TAK3 Actions Taken #3 C 2

21 APP_MOD Apparatus/Personnel Module Used X 1

22 SUP_APP Suppression Apparatus N 4

23 EMS_APP EMS Apparatus N 4

24 OTH_APP Other Apparatus N 4
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-2

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

25 SUP_PER Suppression Personnel N 4

26 EMS_PER EMS Personnel N 4

27 OTH_PER Other Personnel N 4

28 RESOU_AID Resources Include Mutual Aid Y 1

29 PROP_LOSS Property Loss N 9

30 CONT_LOSS Contents Loss N 9

31 PROP_VAL Property Value N 9

32 CONT_VAL Contents Value N 9

33 FF_DEATH Fire Service Deaths N 3

34 OTH_DEATH Other Fire Deaths N 3

35 FF_INJ Fire Service Injuries N 3

36 OTH_INJ Other Fire Injuries N 3

37 DET_ALERT Detector Alerted Occupants C 1

38 HAZ_REL Hazardous Material Released C 1

39 MIXED_USE Mixed Use C 2

40 PROP_USE Property Use C 3

41 CENSUS Census Tract X 6
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-3

APPENDIX C: NFIRS PDR FILE LAYOUTS

Basic Incident Address Table (incidentaddress.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 LOC_TYPE Location Type C 1 Incident Address

7 NUM_MILE Number or Milepost X 8 Incident Address

8 STREET_PRE Street Prefix C 2 Incident Address

9 STREETNAME Street or Highway Name X 30 Incident Address

10 STREETTYPE Street Type C 4 Incident Address

11 STREETSUF Street Suffix C 2 Incident Address

12 APT_NO Apartment Number X 15 Incident Address

13 CITY City X 20 Incident Address

14 STATE_ID State C 2 Incident Address

15 ZIP5 Zip 5 X 5 Incident Address

16 ZIP4 Zip 4 X 4 Incident Address

17 X_STREET Cross Street or Directions X 30 Incident Address
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-4

APPENDIX C: NFIRS PDR FILE LAYOUTS

Basic Incident Aid Given or Received Table (basicaid.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 NFIR_VER NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 FDIDRECAID FDID Receiving Aid X 5

8 FDIDSTREC FDID State Receiving Aid C 2

9 INC_NOFDID Incident Number of FDID Receiving Aid X 7

Fire Incident Table (fireincident.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 NUM_UNIT Number of Residential Units N 4

8 NOT_RES Not Residential Flag Y 1

9 BLDG_INVOL Number of Buildings Involved N 3

10 ACRES_BURN Acres Burned N 6

11 LESS_1ACRE Less Than One Acre Y 1

12 ON_SITE_M1 On Site Materials #1 C 3

13 MAT_STOR1 Material Storage Use #1 C 1

14 ON_SITE_M2 On Site Materials #2 C 3

15 MAT_STOR2 Material Storage Use #2 C 1

16 ON_SITE_M3 On Site Materials #3 C 3
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-5

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

17 MAT_STOR3 Material Storage Use #3 C 1

18 AREA_ORIG Area of Origin C 2

19 HEAT_SOURC Heat Source C 2

20 FIRST_IGN Item First Ignited C 2

21 CONF_ORIG Confined To Origin C 1

22 TYPE_MAT Type of Material C 2

23 CAUSE_IGN Cause of Ignition C 1

24 FACT_IGN_1 Factors Contributing To Ignition #1 C 2

25 FACT_IGN_2 Factors Contributing To Ignition #2 C 2

26 HUM_FAC_1 Human Factors #1 C 1

27 HUM_FAC_2 Human Factors #2 C 1

28 HUM_FAC_3 Human Factors #3 C 1

29 HUM_FAC_4 Human Factors #4 C 1

30 HUM_FAC_5 Human Factors #5 C 1

31 HUM_FAC_6 Human Factors #6 C 1

32 HUM_FAC_7 Human Factors #7 C 1

33 HUM_FAC_8 Human Factors #8 C 1

34 AGE Age of Person F 3.2 Associated with Human Factor code 7

35 SEX Sex of Person C 1 Associated with Human Factor code 7

36 EQUIP_INV Equipment Involved C 3

37 SUP_FAC_1 Suppression Factors #1 C 3

38 SUP_FAC_2 Suppression Factors #2 C 3

39 SUP_FAC_3 Suppression Factors #3 C 3

40 MOB_INVOL Mobile Property Involved C 1

41 MOB_TYPE Mobile Property Type C 2

42 MOB_MAKE Mobile Property Make C 2

43 MOB_MODEL Mobile Property Model X 25

44 MOB_YEAR Mobile Property Year N 4 4 digit year only
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-6

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

45 MOB_LIC_PL Mobile Property License Plate X 10

46 MOB_STATE Mobile Property State C 2

47 MOB_VIN_NO Mobile Property VIN Number X 17

48 EQ_BRAND Equipment Brand X 25

49 EQ_MODEL Equipment Model X 25

50 EQ_SER_NO Equipment Serial Number X 25

51 EQ_YEAR Equipment Year N 4 4 digit year only

52 EQ_POWER Equipment Power C 2

53 EQ_PORT Equipment Portability C 1

54 FIRE_SPRD Fire Spread C 1

55 STRUC_TYPE Structure Type C 1 Beginning of Structure Fire Information

56 STRUC_STAT Structure Status C 1

57 BLDG_ABOVE Building Height: Stories Above Grade N 3

58 BLDG_BELOW Building Height: Stories Below Grade N 2

59 BLDG_LGTH Building Length N 4

60 BLDG_WIDTH Building Width N 4

61 TOT_SQ_FT Total Square Feet N 8

62 FIRE_ORIG Fire Origin N 3 + or -, negative numbers indicate below grade

63 ST_DAM_MIN Number of Stories with Damage: Minor N 3

64 ST_DAM_SIG Number of Stories with Damage: Significant N 3

65 ST_DAM_HVY Number of Stories with Damage: Heavy N 3

66 ST_DAM_XTR Number of Stories with Damage: Extreme N 3

67 FLAME_SPRD No Flame Spread/Same As First/Unknown Y 1

68 ITEM_SPRD Item Contributing Most to Spread C 2

69 MAT_SPRD Type Material Contributing Most To Spread C 2

70 DETECTOR Detector Presence C 1

71 DET_TYPE Detector Type C 1

72 DET_POWER Detector Power C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-7

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

73 DET_OPERAT Detector Operation C 1

74 DET_EFFECT Detector Effectiveness C 1

75 DET_FAIL Detector Failure Reason C 1

76 AES_PRES AES Presence C 1

77 AES_TYPE AES Type C 1

78 AES_OPER AES Operation C 1

79 NO_SPR_OP Number of Sprinklers Operating N 3

80 AES_FAIL AES Failure Reason C 1

Civilian Fire Casualty Table (civiliancasualty.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 SEQ_NUMBER Civilian Fire Casualty Sequence Number N 3 Key Field

7 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

8 GENDER Gender C 1

9 AGE Age F 3.2

10 RACE Race C 1

11 ETHNICITY Ethnicity C 1

12 AFFILIAT Affiliation C 1

13 INJ_DT_TIM Injury Date and Time N 12 MMDDYYYYhhmm

14 SEV Severity C 1

15 CAUSE_INJ Cause of Injury C 1

16 HUM_FACT1 Human Factor Contributing to Injury #1 C 1

17 HUM_FACT2 Human Factor Contributing to Injury #2 C 1

18 HUM_FACT3 Human Factor Contributing to Injury #3 C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-8

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

19 HUM_FACT4 Human Factor Contributing to Injury #4 C 1

20 HUM_FACT5 Human Factor Contributing to Injury #5 C 1

21 HUM_FACT6 Human Factor Contributing to Injury #6 C 1

22 HUM_FACT7 Human Factor Contributing to Injury #7 C 1

23 HUM_FACT8 Human Factor Contributing to Injury #8 C 1

24 FACT_INJ1 Factors Contributing to Injury #1 C 2

25 FACT_INJ2 Factors Contributing to Injury #2 C 2

26 FACT_INJ3 Factors Contributing to Injury #3 C 2

27 ACTIV_INJ Activity When Injured C 1

28 LOC_INC Location at Time of Incident C 1

29 GEN_LOC_IN General Location at Time of Injury C 1

30 STORY_INC Story at Start of Incident N 3 + or -, negative numbers indicate below grade

31 STORY_INJ Story Where Injury Occurred N 3 + or -, negative numbers indicate below grade

32 SPC_LOC_IN Specific Location at Time of Injury C 2

33 PRIM_SYMP Primary Apparent Symptom C 2

34 BODY_PART Primary Part of Body Injured C 1

35 CC_DISPOS Disposition C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-9

APPENDIX C: NFIRS PDR FILE LAYOUTS

Fire Service Casualty Table (ffcasualty.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 FF_SEQ_NO Fire Service Casualty Sequence Number N 3 Key Field

7 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

8 GENDER Gender C 1

9 CAREER Career C 1

10 AGE Age N 3

11 INJ_DATE Injury Date and Time N 12 MMDDYYYYhhmm

12 RESPONSES Responses N 2

13 ASSIGNMENT Usual Assignment C 1

14 PHYS_COND Physical Condition C 1

15 SEVERITY Severity C 1

16 TAKEN_TO Taken to C 1

17 ACTIVITY Activity at Time of Injury C 2

18 SYMPTOM Primary Apparent Symptom C 2

19 PABI Primary Area of Body Injured C 2

20 CAUSE Cause of Firefighter Injury C 1

21 FACTOR Factor Contributing to Injury C 2

22 OBJECT Object Involved in Injury C 2

23 WIO Where Injury Occurred C 1

24 RELATION Injury Relation to Structure C 1

25 STORY Story of Injury N 3 + or -, negative numbers indicate below grade

26 LOCATION Specific Location C 2

27 VEHICLE Vehicle Type C 1

28 PROT_EQP Protective Equipment Contributed to Injury C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-10

APPENDIX C: NFIRS PDR FILE LAYOUTS

Fire Service Equipment Failure Table (ffequipfail.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 CAS_SEQ_NO Fire Service Casualty Sequence Number N 3 Key Field

7 EQP_SEQ_NO Equipment Failure Sequence Number N 3 Key Field

8 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

9 EQUIP_ITEM Equipment Item C 2

10 EQP_PROB Equipment Problem C 2

11 EQP_MAN Equipment Manufacturer X 12

12 EQP_MOD Equipment Model X 12

13 EQP_SER_NO Equipment Serial Number X 12
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-11

APPENDIX C: NFIRS PDR FILE LAYOUTS

Wildland Fire Table (wildlands.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 LATITUDE Latitude F 2.2

8 LONGITUDE Longitude F 3.2

9 TOWNSHIP Township F 3.1

10 NORTH_SOU North/South C 1

11 RANGE Range N 3

12 EAST_WEST East/West C 1

13 SECTION Section N 2

14 SUBSECTION Subsection C 4

15 MERIDIAN Meridian C 2

16 AREA_TYPE Area Type C 1

17 FIRE_CAUSE Wildland Fire Cause C 1

18 HUM_FACT1 Human Factors Contributing #1 C 1

19 HUM_FACT2 Human Factors Contributing #2 C 1

20 HUM_FACT3 Human Factors Contributing #3 C 1

21 HUM_FACT4 Human Factors Contributing #4 C 1

22 HUM_FACT5 Human Factors Contributing #5 C 1

23 HUM_FACT6 Human Factors Contributing #6 C 1

24 HUM_FACT7 Human Factors Contributing #7 C 1

25 HUM_FACT8 Human Factors Contributing #8 C 1

26 FACT_IGN1 Factors Contributing to Ignition #1 C 2

27 FACT_IGN2 Factors Contributing to Ignition #2 C 2

28 SUPP_FACT1 Fire Suppression Factors #1 C 3
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-12

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

29 SUPP_FACT2 Fire Suppression Factors #2 C 3

30 SUPP_FACT3 Fire Suppression Factors #3 C 3

31 HEAT_SOURC Heat Source C 2

32 MOB_PROP Mobile Property Type C 2

33 EQ_INV_IGN Equipment Involved In Ignition C 3

34 NFDRS_ID NFDRS Weather Station ID A 6

35 WEATH_TYPE Weather Type C 2

36 WIND_DIR Wind Direction C 1

37 WIND_SPEED Wind Speed N 3

38 AIR_TEMP Air Temperature N 3 + or -

39 REL_HUMID Relative Humidity N 3

40 FUEL_MOIST Fuel Moisture N 2

41 DANGR_RATE Fire Danger Rating C 1

42 BLDG_INV Number of Buildings Involved N 3

43 BLDG_THR Number of Buildings Threatened N 3

44 ACRES_BURN Total Acres Burned F 9.1

45 CROP_BURN1 Primary Crop Burned 1 X 25

46 CROP_BURN2 Primary Crop Burned 2 X 25

47 CROP_BURN3 Primary Crop Burned 3 X 25

48 UNDET_BURN Undetermined Acres Burned % N 3

49 TAX_BURN Tax Paying Acres Burned % N 3

50 NOTAX_BURN Non-Tax Paying Acres Burned % N 3

51 LOCAL_BURN City, Town, Village, Local Acres Burned % N 3

52 COUTY_BURN County or parish Acres Burned % N 3

53 ST_BURN State or province Acres Burned % N 3

54 FED_BURN Federal Acres Burned % N 3

55 FOREI_BURN Foreign Acres Burned % N 3

56 MILIT_BURN Military Acres Burned % N 3
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-13

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

57 OTHER_BURN Other Acres Burned % N 3

58 PROP_MANAG Property Management Ownership C 1

59 FED_CODE Federal Agency Code X 5

60 NFDRS_FM NFDRS Fuel Model at Origin C 2

61 PERSON_FIR Person Responsible for Fire C 1

62 GENDER Gender C 1

63 AGE Age F 3.2

64 ACTIVITY_W Activity of Person C 2

65 HORIZ_DIS Horizontal Distance From ROW N 2

66 TYPE_ROW Type of ROW C 3

67 ELEVATION Elevation N 5

68 POS_SLOPE Relative Position on Slope C 1

69 ASPECT Aspect C 1

70 FLAME_LGTH Flame Length N 2

71 SPREAD_RAT Rate of Spread N 3
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-14

APPENDIX C: NFIRS PDR FILE LAYOUTS

EMS Table (ems.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 PATIENT_NO EMS Patient Sequence Number N 3 Key Field

7 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

8 ARRIVAL Arrived at Patient Date and Time N 12 MMDDYYYYhhmm

9 TRANSPORT Patient Transfer Date and Time N 12 MMDDYYYYhhmm

10 PROVIDER_A Provider Impression/Assessment C 2

11 AGE Age F 3.2

12 GENDER Gender C 1

13 RACE Race C 1

14 ETH_EMS Ethnicity C 1

15 HUM_FACT1 Human Factors #1 C 1

16 HUM_FACT2 Human Factors #2 C 1

17 HUM_FACT3 Human Factors #3 C 1

18 HUM_FACT4 Human Factors #4 C 1

19 HUM_FACT5 Human Factors #5 C 1

20 HUM_FACT6 Human Factors #6 C 1

21 HUM_FACT7 Human Factors #7 C 1

22 HUM_FACT8 Human Factors #8 C 1

23 OTHER_FACT Other Factors C 1

24 SITE_INJ1 Body Sites of Injury #1 C 1

25 SITE_INJ2 Body Sites of Injury #2 C 1

26 SITE_INJ3 Body Sites of Injury #3 C 1

27 SITE_INJ4 Body Sites of Injury #4 C 1

28 SITE_INJ5 Body Sites of Injury #5 C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-15

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

29 INJ_TYPE1 Injury Types #1 C 2

30 INJ_TYPE2 Injury Types #2 C 2

31 INJ_TYPE3 Injury Types #3 C 2

32 INJ_TYPE4 Injury Types #4 C 2

33 INJ_TYPE5 Injury Types #5 C 2

34 CAUSE_ILL Cause of Illness/Injury C 2

35 PROC_USE1 Procedures Used #1 C 2

36 PROC_USE2 Procedures Used #2 C 2

37 PROC_USE3 Procedures Used #3 C 2

38 PROC_USE4 Procedures Used #4 C 2

39 PROC_USE5 Procedures Used #5 C 2

40 PROC_USE6 Procedures Used #6 C 2

41 PROC_USE7 Procedures Used #7 C 2

42 PROC_USE8 Procedures Used #8 C 2

43 PROC_USE9 Procedures Used #9 C 2

44 PROC_USE10 Procedures Used #10 C 2

45 PROC_USE11 Procedures Used #11 C 2

46 PROC_USE12 Procedures Used #12 C 2

47 PROC_USE13 Procedures Used #13 C 2

48 PROC_USE14 Procedures Used #14 C 2

49 PROC_USE15 Procedures Used #15 C 2

50 PROC_USE16 Procedures Used #16 C 2

51 PROC_USE17 Procedures Used #17 C 2

52 PROC_USE18 Procedures Used #18 C 2

53 PROC_USE19 Procedures Used #19 C 2

54 PROC_USE20 Procedures Used #20 C 2

55 PROC_USE21 Procedures Used #21 C 2

56 PROC_USE22 Procedures Used #22 C 2

57 PROC_USE23 Procedures Used #23 C 2
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-16

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

58 PROC_USE24 Procedures Used #24 C 2

59 PROC_USE25 Procedures Used #25 C 2

60 SAFE_EQP1 Safety Equipment Used #1 C 1

61 SAFE_EQP2 Safety Equipment Used #2 C 1

62 SAFE_EQP3 Safety Equipment Used #3 C 1

63 SAFE_EQP4 Safety Equipment Used #4 C 1

64 SAFE_EQP5 Safety Equipment Used #5 C 1

65 SAFE_EQP6 Safety Equipment Used #6 C 1

66 SAFE_EQP7 Safety Equipment Used #7 C 1

67 SAFE_EQP8 Safety Equipment Used #8 C 1

68 ARREST Pre or Post Arrival Arrest C 1

69 ARR_DES1 Pre-Arrival Arrest Descriptors #1 C 1

70 ARR_DES2 Pre-Arrival Arrest Descriptors #2 C 1

71 AR_RHYTHM Initial Arrest Rhythm C 1

72 IL_CARE Initial Level of Care C 1

73 HIGH_CARE Highest Level of Care C 1

74 PAT_STATUS Patient Status C 1

75 PULSE Pulse on Transfer C 1

76 EMS_DISPO Disposition C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-17

APPENDIX C: NFIRS PDR FILE LAYOUTS

Hazardous Material Table (hazmat.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 REL_FROM Released From C 1

8 REL_STORY Story of Release N 3 + or -, negative numbers indicate below grade

9 POP_DENS Population Density C 1

10 AFFEC_MEAS Area Affected Measurement N 4

11 AFFEC_UNIT Area Affected Units C 1

12 EVAC_MEAS Area Evacuated Measurement N 4

13 EVAC_UNIT Area Evacuated Units C 1

14 PEOP_EVAC Estimated Number of People Evacuated N 6

15 BLDG_EVAC Estimated Number of Buildings Evacuated N 4

16 HAZ_ACT1 Hazmat Actions Taken #1 C 2

17 HAZ_ACT2 Hazmat Actions Taken #2 C 2

18 HAZ_ACT3 Hazmat Actions Taken #3 C 2

19 OCCUR_FIRS Occurred First C 1

20 CAUSE_REL Cause of Release C 1

21 FACT_REL1 Factors Contributing to Release #1 C 2

22 FACT_REL2 Factors Contributing to Release #2 C 2

23 FACT_REL3 Factors Contributing to Release #3 C 2

24 MIT_FACT1 Mitigating Factors #1 C 2

25 MIT_FACT2 Mitigating Factors #2 C 2

26 MIT_FACT3 Mitigating Factors #3 C 2

27 EQ_INV_REL Equipment Involved in Release C 3

28 HAZ_DISPO Disposition C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-18

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

29 HAZ_DEATH Hazmat Civilian Deaths N 4

30 HAZ_INJ Hazmat Civilian Injuries N 4

Hazardous Material Chemical Table (hazchem.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 SEQ_NUMBER Hazmat Chemical Sequence Number N 2 Key Field

7 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

8 UN_NUMBER UN Number X 4

9 DOT_CLASS DOT Hazard Classification C 2

10 CAS_REGIS CAS Registration X 10

11 CHEM_NAME Chemical Name X 50

12 CONT_TYPE Container Type C 2

13 CONT_CAP Estimated Container Capacity N 9

14 CAP_UNIT Capacity Units C 2

15 AMOUNT_REL Estimated Amount Released N 9

16 UNITS_REL Released Units C 2

17 PHYS_STATE Physical State When Released C 1

18 REL_INTO Released Into C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-19

APPENDIX C: NFIRS PDR FILE LAYOUTS

Hazardous Material Mobile Property Type Table (hazmobprop.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 MP_TYPE Mobile Property Type C 2

8 MP_MAKE Mobile Property Make C 2

9 MP_MODEL Mobile Property Model X 25

10 MP_YEAR Mobile Property Year N 4 4 digit year only

11 MP_LICENSE Mobile Property License Plate X 10

12 MP_STATE Mobile Property State C 2

13 MP_DOT_ICC Mobile Property DOT/ICC Number X 17

Hazardous Material Equipment Involved Table (hazmatequipinvolved.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 EQ_BRAND Equipment Brand X 25

8 EQ_MODEL Equipment Model X 25

9 EQ_SER_NO Equipment Serial Number X 25

10 EQ_YEAR Equipment Year N 4 4 digit year only
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-20

APPENDIX C: NFIRS PDR FILE LAYOUTS

Arson Table (arson.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 CASE_STAT Case Status C 1

8 AVAIL_MFI Availability of Material First Ignited C 1

9 MOT_FACTS1 Suspected Motivation Factors #1 C 2

10 MOT_FACTS2 Suspected Motivation Factors #2 C 2

11 MOT_FACTS3 Suspected Motivation Factors #3 C 2

12 GRP_INVOL1 Apparent Group Involvement #1 C 1

13 GRP_INVOL2 Apparent Group Involvement #2 C 1

14 GRP_INVOL3 Apparent Group Involvement #3 C 1

15 ENTRY_METH Entry Method C 2

16 EXT_FIRE Extent of Fire Involvement on Arrival C 1

17 DEVI_CONT Incendiary Devices: Container C 2

18 DEVI_IGNIT Incendiary Devices: Ignition/Delay Device C 2

19 DEVI_FUEL Incendiary Devices: Fuel C 2

20 INV_INFO1 Other Investigative Information #1 C 1

21 INV_INFO2 Other Investigative Information #2 C 1

22 INV_INFO3 Other Investigative Information #3 C 1

23 INV_INFO4 Other Investigative Information #4 C 1

24 INV_INFO5 Other Investigative Information #5 C 1

25 INV_INFO6 Other Investigative Information #6 C 1

26 INV_INFO7 Other Investigative Information #7 C 1

27 INV_INFO8 Other Investigative Information #8 C 1

28 PROP_OWNER Property Ownership C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-21

APPENDIX C: NFIRS PDR FILE LAYOUTS

Field Number .DBF Field Name Field Name Data Type Length Comments

29 INIT_OB1 Initial Observations #1 C 1

30 INIT_OB2 Initial Observations #2 C 1

31 INIT_OB3 Initial Observations #3 C 1

32 INIT_OB4 Initial Observations #4 C 1

33 INIT_OB5 Initial Observations #5 C 1

34 INIT_OB6 Initial Observations #6 C 1

35 INIT_OB7 Initial Observations #7 C 1

36 INIT_OB8 Initial Observations #8 C 1

37 LAB_USED1 Laboratory Used #1 C 1

38 LAB_USED2 Laboratory Used #2 C 1

39 LAB_USED3 Laboratory Used #3 C 1

40 LAB_USED4 Laboratory Used #4 C 1

41 LAB_USED5 Laboratory Used #5 C 1

42 LAB_USED6 Laboratory Used #6 C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-22

APPENDIX C: NFIRS PDR FILE LAYOUTS

Arson Agency Referral Table (arsonagencyreferal.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 AGENCY_NAM Agency Name X 30 Key Field

7 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

8 AG_ST_NUM Agency Street Number X 8

9 AG_ST_PREF Agency Street Prefix C 2

10 AG_STREET Agency Street or Highway X 30

11 AG_ST_TYPE Agency Street Type C 4

 12 AG_ST_SUFF Agency Street Suffix C 2

13 AG_APT_NO Agency Apartment Number X 15

14 AG_CITY Agency City X 20

15 AG_STATE Agency State C 2

16 AG_ZIP5 Agency ZIP 5 Code X 5 1st 5 of Zip

17 AG_ZIP4 Agency ZIP 4 Code X 4 Last 4 of Zip

18 AG_PHONE Agency Phone Number N 10

19 AG_CASE_NO Agency Case Number X 12

20 AG_ORI Agency ORI X 5

21 AG_FID Agency FID X 2

22 AG_FDID Agency FDID X 5
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-23

APPENDIX C: NFIRS PDR FILE LAYOUTS

Arson Juvenile Subject Table (arsonjuvsub.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 SUB_SEQ_NO Subject Sequence Number N 3 Key Field

7 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

8 AGE Age N 3

9 GENDER Gender C 1

10 RACE Race C 1

11 ETHNICITY Ethnicity C 1

12 FAM_TYPE Family Type C 1

13 RISK_FACT1 Motivation/Risk Factors #1 C 1

14 RISK_FACT2 Motivation/Risk Factors #2 C 1

15 RISK_FACT3 Motivation/Risk Factors #3 C 1

16 RISK_FACT4 Motivation/Risk Factors #4 C 1

17 RISK_FACT5 Motivation/Risk Factors #5 C 1

18 RISK_FACT6 Motivation/Risk Factors #6 C 1

19 RISK_FACT7 Motivation/Risk Factors #7 C 1

20 RISK_FACT8 Motivation/Risk Factors #8 C 1

21 JUV_DISPO Disposition C 1
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-24

APPENDIX C: NFIRS PDR FILE LAYOUTS

Fire Department Header Table (fdheader.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 FD_NAME Fire Department Name X 30

4 FD_STR_NO Fire Department Street Number of Milepost X 8

5 FD_STR_PRE Fire Department Street Prefix C 2

6 FD_STREET Fire Department Street or Highway Name X 30

7 FD_STR_TYP Fire Department Street Type C 4

8 FD_STR_SUF Fire Department Street Suffix C 2

9 FD_CITY Fire Department City X 20

10 FD_ZIP Fire Department Zip X 9

11 FD_PHONE Fire Department Phone N 10

12 FD_FAX Fire Department Fax N 10

13 FD_EMAIL Fire Department E-mail X 45

14 FD_FIP_CTY Fire Department FIPS County Code X 3

15 NO_STATION Number of Stations N 3

16 NO_PD_FF Number of Paid Firefighters N 4

17 NO_VOL_FF Number of Volunteer Firefighters N 4

18 NO_VOL_PDC Number of Volunteer Paid Per Call N 4

Code Descriptor Lookup Table (codelookup.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 FIELDID FIELDID X 25 Key Field

2 CODE_VALUE Code Value C 4

3 CODE_DESCR Code Descriptor X 50
NFIRS 5.0 Fire Data Analysis Guidelines and Issues C-25

APPENDIX C: NFIRS PDR FILE LAYOUTS

NFIRS 4.1 Legacy Field Table (legacyfields.dbf)

Field Number .DBF Field Name Field Name Data Type Length Comments

1 STATE Fire Dept. State C 2 Key Field

2 FDID Fire Dept. ID X 5 Key Field

3 INC_DATE Incident Date N 8 Key Field (MMDDYYYY)

4 INC_NO Incident Number X 7 Key Field

5 EXP_NO Exposure Number N 3 Key Field

6 VERSION NFIRS Data Version X 5 Data Version (converted 4.1 or 5.0)

7 METH_ALARM Method of Alarm C 1 NFIRS 4.1 legacy field

8 METH_EXTIN Method of Extinguishment C 1 NFIRS 4.1 legacy field

9 CONST_TYPE Construction Type C 1 NFIRS 4.1 legacy field

10 SMOKE_DAM Extent of Smoke Damage C 1 NFIRS 4.1 legacy field

11 TYPE_MSMOK Type Material Generating Most Smoke C 2 NFIRS 4.1 legacy field

12 FORM_MSMOK Form of Material Generating Most Smoke C 2 NFIRS 4.1 legacy field

13 AVE_SMKTRV Avenue of Smoke Travel C 1 NFIRS 4.1 legacy field