ASTM E1546-21

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1546 − 21 An American National Standard
Standard Guide for
Development of Fire-Hazard-Assessment Standards
This standard is issued under the fixed designation E1546; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This guide covers the development of fire-hazard-
1.8 This fire standard cannot be used to provide quantitative
assessment standards.
measures.
1.2 This guide is directed toward development of standards
1.9 This standard is used to predict or provide a quantitative
that will provide procedures for assessing fire hazards harmful
measureofthefirehazardfromaspecifiedsetoffireconditions
to people, animals, or property.
involving specific materials, products, or assemblies. This
1.3 Fire-hazardassessmentandfire-riskassessmentareboth assessment does not necessarily predict the hazard of actual
procedures for assessing the potential for harm caused by
fires which involve conditions other than those assumed in the
something–thesubjectoftheassessment–whenitisinvolvedin analysis.
fire, where the involvement in fire is assessed relative to a
1.10 This international standard was developed in accor-
number of defined fire scenarios.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
1.4 Both fire-hazard assessment and fire-risk assessment
Development of International Standards, Guides and Recom-
provide information that can be used to address a larger group
mendations issued by the World Trade Organization Technical
of fire scenarios. Fire-hazard assessment provides information
Barriers to Trade (TBT) Committee.
on the maximum potential for harm that can be caused by the
fire scenarios that are analyzed or by any less severe fire
2. Referenced Documents
scenarios.Fire-riskassessmentusesinformationontherelative
2.1 ASTM Standards:
likelihood of the fire scenarios that are analyzed and the
additionalfirescenariosthateachanalyzedscenariorepresents. D2859 Test Method for Ignition Characteristics of Finished
Textile Floor Covering Materials
In these two ways, fire-hazard assessment and fire-risk assess-
ment allow the user to support certain statements about the D5425 Guide for Development of Fire Hazard Assessment
Standards of Electrotechnical Products
potential for harm caused by something when it is involved in
fire, generally. E176 Terminology of Fire Standards
E603 Guide for Room Fire Experiments
1.5 Fire-hazard assessment is appropriate when the goal is
E648 Test Method for Critical Radiant Flux of Floor-
to characterize maximum potential for harm under worst-case
Covering Systems Using a Radiant Heat Energy Source
conditions.Fire-riskassessmentisappropriatewhenthegoalis
E1354 Test Method for Heat and Visible Smoke Release
tocharacterizeoverallrisk(averageseverity)ortocharacterize
Rates for Materials and Products Using an Oxygen Con-
the likelihood of worst-case outcomes. It is important that the
sumption Calorimeter
userselecttheappropriatetypeofassessmentprocedureforthe
E1678 Test Method for Measuring Smoke Toxicity for Use
statements the user wants to support.
in Fire Hazard Analysis
1.6 Fire-hazard assessment is addressed in this guide and
E1776 Guide for Development of Fire-Risk-Assessment
fire-risk assessment is addressed in Guide E1776.
Standards
E2061 Guide for Fire Hazard Assessment of Rail Transpor-
1.7 This standard does not purport to address all of the
tation Vehicles
safety concerns, if any, associated with its use. It is the
E2280 Guide for Fire Hazard Assessment of the Effect of
responsibility of the user of this standard to establish appro-
Upholstered Seating Furniture Within Patient Rooms of
Health Care Facilities
ThisguideisunderthejurisdictionofASTMCommitteeE05onFireStandards
and is the direct responsibility of Subcommittee E05.33 on Fire Safety Engineering. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2021. Published August 2021. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1993. Last previous edition approved in 2015 as E1546–15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/E1546-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1546 − 21
2.2 ISO Standards: presented with the same risk situation may have different
ISO 13943 Fire Safety – Vocabulary opinions on its acceptability.
2.3 NFPA Standards:
3.2.5 fire scenario, n—a detailed description of conditions,
NFPA 101 Code for Safety to Life from Fire in Buildings
including environmental, of one or more of the stages from
and Structures
before ignition to the completion of combustion in an actual
NFPA 901 Uniform Coding for Fire Protection
fire, or in a full scale simulation.
2.4 SFPE Standards:
3.2.5.1 Discussion—The conditions describing a fire
SFPE Engineering Guide to Performance-Based Fire Protec-
scenario, or a group of fire scenarios, are those required for the
tion
testing, analysis, or assessment that is of interest. Typically,
they are those conditions that can create significant variation in
3. Terminology
theresults.Thedegreeofdetailnecessarywilldependuponthe
3.1 Definitions of Terms—See Terminology E176 and ISO
intended use of the fire scenario. Environmental conditions
13943. In case of conflict the definitions in Terminology E176
may be included in a scenario definition but are not required in
shall prevail.
all cases. Fire scenarios often define conditions in the early
stages of a fire while allowing analysis to calculate conditions
3.2 Definitions:
in later stages.
3.2.1 environment, n—as related to fire, the conditions and
surroundings that may influence the behavior of a material,
3.2.6 fire test response characteristic, n—a response char-
product, or assembly when it is exposed to ignition sources of
acteristic of a material, product, or assembly to a prescribed
fire.
source of heat or flame, under controlled fire conditions; such
3.2.2 fire-characteristic profile, n—an array of fire-test-
response characteristics may include, but are not limited to,
response characteristics, all measured using tests relevant to ease of ignition, flame spread, heat release, mass loss, smoke
the same fire scenario, for a material, product, or assembly, to
generation, fire endurance, and toxic potency of smoke.
address, collectively, the corresponding fire hazard. See also
3.2.6.1 Discussion—A fire-test-response characteristic can
fire hazard, fire riskand fire-test response characteristic.
be influenced by variable characteristics of the heat source,
3.2.2.1 Discussion—An array of fire-test-response charac-
such as it intensity, or of the burning environment, such as
teristicsinasetofdatarelevanttotheassessmentoffirehazard
ventilation,geometryofitemorenclosure,humidity,oroxygen
in a particular fire sceanrio. In other words, all the fire tests
concentration. It is not an intrinsic property such as specific
usedwouldhaveademonstratedvalidityforthefirescenarioin
heat, thermal conductivity, or heat of combustion, where the
question, for example, by having comparable fire intensities.
value is independent of test variables. A fire-test-response
The fire-characteristic profile is intended as a collective guide
characteristic may be described in one of several terms. Smoke
to the potential fire hazard from a material, product, or
generation, for example, may be described as smoke opacity,
assembly involved in a fire that could be represented by the
change of opacity with time, or smoke weight. No quantitative
laboratory test conditions.
correlation need exist between values of a fire-test-response
characteristic for different materials, product, or assemblies, as
3.2.3 fire hazard, n—the potential for harm associated with
measured by different methods or tested under different sets of
fire.
conditions for a given method.
3.2.3.1 Discussion—A fire may pose one or more types of
hazard to people, animals, or property. These hazards are
3.3 Definitions of Terms Specific to This Standard:
associated with the environment and with a number of fire-
3.3.1 fire characteristic index, n—a single quantitative mea-
test-response characteristics of materials, products, or assem-
sure that combines two or more fire-test-response characteris-
blies including, but not limited to, ease of ignition, flame
tics for a material, product, or assembly, all developed under
spread, rate of heat release, smoke generation and obscuration,
test conditions compatible with a common fire scenario,
toxicity of combustion products, and ease of extinguishment.
addressing collectively, the corresponding threat. See also
3.2.4 fire risk, n—an estimation of expected fire loss that
fire-characteristics profile, fire hazard, fire risk, fire-test-
combines the potential for harm in various scenarios that can
response characteristic.
occur with the probabilities of occurrence of those scenarios.
3.3.2 fire hazard assessment, n—a process for measuring or
3.2.4.1 Discussion—Risk may be defined as the probability
calculating the potential for harm created by the presence of a
of having a certain type of fire, where the type of fire may be
material, product, or assembly in the relevant fire scenarios.
defined in whole or part by the degree of potential harm
3.3.3 fire risk assessment, n—a means for computing the
associated with it, or as potential for harm weighted by
associated probabilities. However, it is defined, no risk scale probability of fire loss within a specified period in a defined
occupancy or situation.
implies a single value of acceptable risk. Different individuals
4. Significance and Use
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org.
4.1 This guide is intended for use by those undertaking the
Available from National Fire Protection Association (NFPA), 1 Batterymarch
development of fire-hazard-assessment standards. Such stan-
Park, Quincy, MA 02169-7471, http://www.nfpa.org.
dards are expected to be useful to manufacturers, architects,
Available from Society of Fire Protection Engineers (SFPE), 7315 Wisconsin
Ave., Suite 620E, Bethesda, MD 20814, http://www.sfpe.org. specification writers, and authorities having jurisdiction.
E1546 − 21
4.2 As a guide, this document provides information on an for use within the specified fire-hazard-assessment or fire-risk-
approach to the development of a fire hazard standard; fixed assessment procedure through final publication of the fire-
procedures are not established. Limitations of data, available hazard-assessment or fire-risk-assessment standard document.
tests and models, and scientific knowledge may constitute
5.1.5.1 The concepts discussed in 5.1.5 apply both to
significantconstraintsonthefire-hazard-assessmentprocedure.
fire-hazard assessments, conducted in accordance with this
guide, and to fire-risk assessments, conducted in accordance
4.3 While the focus of this guide is on developing fire-
with Guide E1776.
hazard-assessment standards for products, the general concepts
5.1.6 Among the significant outcomes of a fire-hazard
presented also may apply to processes, activities, occupancies,
assessment would be the revelation that a product produces
and buildings.
either an increase, no increase, or a decrease in fire hazard on
4.4 When developing fire-risk-assessment standards, use
some or all hazard measures and for all or some of the
Guide E1776. The present guide also contains some of the
scenarios specified by the standard, relative to another product
guidance to develop such a fire-risk assessment standard.
or relative to baseline hazard values for those measures and
scenarios. These baseline values may or may not be derived
5. Key Elements
from fire-hazard assessments of products already in use.
5.1 This guide uses as its key elements the following:
However, when the product is proposed for an existing use, it
5.1.1 The purpose of a fire-hazard-assessment standard or a
should be compared to an existing product having the same
fire-risk-assessment standard is to provide a standardized
use. For example, if a product’s fire hazard is uniformly rated
procedureforassemblingacompilationofinformationrelevant
greater than the reference values on all comparisons specified
to the fire hazard or fire risk of a product under specific
by the standard, then the overall fire-hazard assessment of the
conditions of use.
product will be greater than the fire hazard of the baseline (or
5.1.2 The information assembled by using a fire-hazard-
product in use).
assessment standard should be relevant to the purpose of
5.1.7 If the assessment shows that the product is not
assessing the fire hazard of the specific designated product
uniformly rated higher than, equivalent to, or less than the
within the range of designated fire scenarios. The information
other product(s) or the baseline for all hazard measures and
assembled by using a fire-risk-assessment standard (see Guide
reflecting all scenarios specified by the standard, then the
E1776) should be relevant to the purpose of assessing the fire
implications of the fire-risk assessment for product evaluation
risk of the specific designated product within the range of all
(inaccordancewithGuideE1776)willnotbeclearwithoutthe
relevant scenarios.
development of appropriate decision rules. Such rules would
5.1.3 The information assembled should be explicit and
combine the fire hazard or fire risk measures, giving appropri-
quantitative and should provide a sufficiently thorough exami-
ate weighting to each fire-hazard or fire-risk measure, and, if
nation of the product’s fire hazard under the conditions defined
necessary, would combine measures for different scenarios,
by the scope of the specific standard, so as to permit valid
giving appropriate weighting to each scenario. Decision rules
choices and decisions with respect to the fire hazard of that
for combining measures need not be simple weighted sums of
product.
the component measures. Decision rules for combining sce-
5.1.4 A persuasive scientific case must be made in the
nariosnormallyuseweightsreflectingtherelativelikelihoodof
documentation of a specific fire-hazard-assessment standard
different scenarios. Fire-risk-assessment standards normally
that the procedures, data, and hazard measures specified by the
include procedures for combining scenarios, but fire-hazard-
standard will address questions about a product’s fire hazard
assessment standards normally do not. Note that the scenario
with sufficient accuracy and validity that a more thorough
may affect not only the value of individual fire hazard or fire
assessment procedure would not materially alter any decisions
risk measures but also the decision rules for combining fire
thatmightbemadebasedonthestandard.Ifsuchacasecannot
hazard or fire risk measures (in the latter case by using Guide
be made for all products to be addressed, then the hazard
E1776).
assessment should specify those conditions under which a
more thorough fire-hazard-assessment procedure should be
6. Relationship Between Fire Hazard and Fire Risk
used. In some cases, the more thorough assessment procedure
6.1 It is important to differentiate between fire hazard and
identified by a fire-hazard-assessment standard can be consid-
fire risk (see 3.1 for the definitions). The relationship is as
ered to be a fire-risk-assessment procedure, but this must be
follows.
confirmed via Guide E1776.
6.1.1 A fire-hazard measure addresses the expected perfor-
5.1.5 The absence of a data source, test method, or calcu-
mance of a product for a particular fire scenario, including
lation procedure of sufficient scope and proven validity to
designated conditions of use. A fire-risk measure incorporates
support the needs of a particular fire-hazard-assessment proce-
fire-hazard measures but also incorporates probability of oc-
dure may not be a sufficient reason to use a data source, test
currence of each fire scenario and addresses all relevant fire
method, or calculation procedure of lesser scope or unproven
scenarios.
validity. It is recognized that fire-hazard assessments of such
productsmayneedtobeperformedinanyevent,usingrelevant 6.1.2 Because the number of distinguishable relevant fire
non-standardized procedures. When such non-standardized or scenarios in any fire-risk assessment is usually unmanageably
unvalidated procedures are used, the details shall be included large, it will normally be necessary for fire scenarios to be
tosuchanextentthattheproceduresbecomestandardizedonly grouped into classes for purposes of analysis. This may make
E1546 − 21
the fire-risk assessment less product-specific or less specific to 7. Fire-Hazard-Assessment Standards
conditions of use than would be true of a fire-hazard assess-
7.1 Fire-hazard-assessment standards shall conform in style
ment.
and content to the ASTM Form and Style Manual.
6.1.3 Some existing fire-risk assessment models and calcu-
7.2 Fire-hazard-assessment standards shall include sections
lation procedures define fire risk as the sum over all fire
labeled: Scope, Significance and Use, Terminology, and De-
scenario classes of the probability-weighted fire hazard for that
tailed Procedure; the sections should be numbered and ar-
fire scenario class. In such an approach:
ranged in that order.
6.1.3.1 The fire scenarios in each fire scenario class shall be
7.2.1 Scope—the Scope statement should clearly state:
verysimilarwithrespecttothosecharacteristicsthatdetermine 7.2.1.1 The product or class of products of interest,
fire hazard. 7.2.1.2 Thefirescenario(s)includedinthestandard,and,for
a fire-risk assessment, in accordance with Guide E1776, the
6.1.3.2 Each fire scenario class will have a probability (P)
i
scenario class represented by each fire scenario,
that represents the likelihood of a fire corresponding to a
7.2.1.3 The assumptions used in the standard,
scenario in that class.
7.2.1.4 The structure of the fire-hazard-assessment
6.1.3.3 For each fire scenario class, a specific fire scenario
procedure, including test methods, models, other calculation
shall be chosen as representative of the class, so that the fire
procedures, data sources, hazard measures, and evaluation
hazard for that specific fire scenario can be used as a valid
criteria or procedures used, and
estimate of H, the fire hazard of the fire scenario class. This is
i
7.2.1.5 Any limitations on the application of the standard,
defined as the probability-weighted mean fire hazard for all the
such as the manner, form, or orientation in which the product
specific fire scenarios in the fire scenario class, a quantity that
is incorporated within an assembly, geometric restrictions
cannot be directly calculated.
essential to use of the product, the quantity of product in use,
6.1.3.4 If this structure is adopted, then the relationship the end use of the product, and the type of occupancy to which
between the fire risk measure and fire hazard measure is given the standard is applicable.
7.2.2 Significance and Use:
by the following formula:
7.2.2.1 The major uses and any limitations of the standard
Risk 5 P 3 H (1)
~ !
i i
(i
fire-hazard-assessment procedure should be clearly described.
For fire-risk-assessment procedures, in accordance with Guide
where:
E1776, this should include an explicit description of the extent
H = hazard for representative scenario of scenario class i,
i
to which the included fire scenario classes and representative
i = 1,.n, and
firescenarios,in7.2.1.2,constitutealltherelevantfirescenario
H = probability of scenario class i, i = 1, .n.
i
classes and representative fire scenarios for the product (class)
6.1.4 For a fire-risk-assessment standard, this formula
and occupancy type addressed by the standard.
showsthatafire-risk-assessmentproceduremaybeconstructed
7.2.2.2 The significance of the assessment to users should
from a fire-hazard-assessment procedure, a valid structure of
be clearly stated.
fire scenario class and representative fire scenarios by class, 7.2.3 Terminology—Terms unique to the fire-hazard-
and valid sources for fire scenario class probability data. assessment standard should be clearly defined. Standard terms
as defined in Terminology E176 shall be used. Terms not
6.1.5 Theprincipaldifferencesbetweenafire-hazardassess-
included in Terminology E176 but useful for this guide are
ment and a fire-risk assessment are (a) a fire-risk assessment
included in 3.3.
incorporates relative scenario likelihood into the information
7.2.4 Detailed Procedure:
provided in the assessment, whereas a fire-hazard assessment
7.2.4.1 This section should include detailed descriptions of
normally does not do so; and (b) the scenarios in a fire-risk
the fire-hazard-assessment procedure and its component parts,
assessment need to be chosen so that they collectively repre-
including: test methods, calculation procedures, scenario
sent all relevant fire scenarios, whereas the scenarios in a
description,datasources,andevaluationcriteriaorprocedures.
fire-hazard assessment need only be chosen so that a more
7.2.4.2 If the calculation procedures include models, the
thorough assessment would not materially alter any decisions
versions used should be carefully identified and referenced and
made based on the assessment and the standard.
major assumptions and limitations of the models noted. Vali-
6.1.6 A fire-risk assessment may be most appropriate when
dation information, or lack thereof, should also be noted.
it is not possible to demonstrate that use of a fire-hazard
7.2.4.3 If calculation procedures are used, sample calcula-
assessment will not materially alter any decisions made based
tions should be included.
on the assessment and the standard, relative to decisions that
7.2.4.4 Standard test methods should be carefully identified
would have been made using a fire-risk assessment. A fire-
and referenced. If a test method not yet adopted as a national
hazard assessment may be acceptable and more efficient when
the purpose is only to demonstrate that consequences are 6
Available from ASTM International, 100 Barr Harbor Drive, PO Box C700,
acceptably small for each scenario analyzed. West Conshohocken, PA 19428–2959. http://www.astm.org.
E1546 − 21
standard is used, its descriptions should provide all the infor- assessingfireriskinaccordancewithGuideE1776,probability
mation that would be included if it were being submitted assessments will be needed),
separately for consideration as a standard test method. Data on
8.2.5 Use the scenarios to define key parameters of the test
reproducibility and validation of non-standardized methods
methods or calculation procedures,
shouldbeincluded.Ifastandardtestmethodhasbeenmodified
8.2.6 Identify the types and sources of data required to
for the standard, all details of the modification and evidence of
support the selected test methods and calculation procedures,
the effects of the modification on results should be included.
identified in 8.2.2 – 8.2.5 (note also that, when assessing fire
These guidelines also apply to any large-scale test protocols.
risk, in accordance with Guide E1776, it will be necessary to
7.2.4.5 If sources for data on fire experience or expert
identify the types and sources of data required for calculation
judgment are cited, the procedures for assembling the data and
of needed probabilities), and
the accuracy, precision, and reliability of the data should be
8.2.7 Identify the criteria or procedures for evaluating the
documented. The data should be accessible to personnel
fire hazard measures relative to the degree of harm.
conducting or reviewing the fire-hazard assessment.
8.2.8 Identify the necessary safety factors, sensitivity
analyses, or other elements required to permit valid interpre-
8. Fire-Hazard-Assessment Procedures
tation of the fire-hazard in light of the uncertainties and biases
of data or calculation methods, which should have been
8.1 Overview of Elements of Fire Hazard:
previously documented in 8.2.2 – 8.2.7
8.1.1 Possiblesourcesofharmtopeopleoranimals,directly
8.2.9 Fig. 1 graphically displays the steps in 8.2.1 – 8.2.8,
or indirectly, include toxic (narcotic or irritant) substances
where the left side shows steps for fire-hazard assessment and
produced by a fire, thermal insults (heat stress and burns) due
the right side shows steps for fire-risk assessment, in accor-
to convected and radiant flux, obscuration of vision by smoke
dance with Guide E1776.
(which may interfere with the ability to escape), oxygen
depletion, and structural damage leading to traumatic injury.
8.3 Define the Scope and Context—The first step involves
8.1.2 Possible sources of harm to property include direct
defining the products or class of products to which the
damage to contents, furnishings, structure, or other installed or
fire-hazard-assessment standard is to apply (that is, scope) and
moveable combustibles, from heat, corrosive smoke, soot or
defining the general and specific environments in which the
firefighting, and indirect damage as a consequence of business
products will be used (that is, context), including implications
interruption or other adverse effects on the ability of the
of those environments for test conditions or model parameters
property to be used for its designed purposes.
in the fire-hazard-assessment calculation procedure. This may
8.1.3 Harm to the environment includes direct harm to
be accomplished by answering the following questions:
animalsforplantlifelocatedoutsidethepropertyoforigin,and
8.3.1 Product or Class—What is the product or product
indirect harm to people, animals, plant life, or property as a
class to be covered? Is the definition clear enough that one can
result of contamination of air, water, adjacent land.
always determine whether a product is covered by the stan-
8.1.4 The fire hazard or risk of a product depends on its
dard? Is the definition broad enough that all products capable
properties, how it is used, and the context in which it is used,
of substituting for covered products are also included? Is the
including the number and characteristics of people potentially
definition sufficiently specific that it does not invite invalid
exposed, and the value and fragility of property exposed to a
comparisons, such as comparisons of products that have very
fire involving the product. Therefore, a fire-hazard-assessment
dissimilar uses and do not satisfy all the assumptions of the
or fire-risk-assessment procedure for a particular product
standard?
should describe the product, how it is used, and its context of
8.3.2 Product Involvement in Fire—When and how does the
use.
product tend to become involved in fire? Is there a particular
role in fire that tends to be the only point of concern for this
8.2 Development of a Fire-Hazard-Assessment Standard—
product class in a specific use (for example, initial heat source,
The seven basic steps to follow in developing a fire-hazard-
initialfuelsource,principalorlargestfuelsource,highseverity
assessment standard are the following:
per unit of product, major avenue of fire spread, major part of
8.2.1 Define the scope (for example, the product(s) or
value at risk)? Based on this information, is there a subset of
productclassofinterest,whereandhowtheproductsareused),
the following fire-test-response and other characteristics that
8.2.2 Identify the measure of harm to be assessed (for
can validly be isolated as the only ones providing significant
example, deaths, injuries, business loss, property loss),
variation in fire hazard for this product class? Consider the
8.2.3 Identify and describe the fire scenarios to be analyzed
following:
(for example, geometry, ventilation, and other special charac-
8.3.2.1 Ignitability,
teristics of environment; initial heat source; initial fuel source
8.3.2.2 Flame-spread rate,
if not the product; locations and burning properties of second-
8.3.2.3 Heat release—peak rate, rate of rise in rate (fire
ary fuel sources; occupant characteristics), and for fire-risk
growth rate), total heat released,
assessment (in accordance with Guide E1776), including the
8.3.2.4 Mass loss or smoke-generation rate,
scenario classes represented by each scenario selected for
analysis, 8.3.2.5 Opacity of smoke produced (also described as
smoke obscuration),
8.2.4 Identify the test methods or calculation procedures
needed to produce the measures of fire hazard (note that, when 8.3.2.6 Corrosivity of smoke produced,
E1546 − 21
FIG. 1 Flow Chart Showing Steps in Fire-Hazard or Fire-Risk Assessment
8.3.2.7 Profile of toxic (irritant and asphyxiant) species 8.3.2.9 Fire resistance – structural integrity, thermal
produced—rate, total, toxic potency, conductivity, mechanical response (for example, melting,
8.3.2.8 Thermal-decomposition rates, collapsing),
E1546 − 21
8.3.2.10 Ease of extinguishment, and the property? Is the product typically used as a single unit or as
a component of an assembly? Are there other products nor-
8.3.2.11 Quantity of product in use relative to size and type
mally associated with the product in question (for example, a
of occupancy.
carpetanditspad)orinstallationproceduresthatmayaffectthe
8.3.3 Environment:
fire-hazard development of the product? Is more, or less,
8.3.3.1 Whataretheenvironmentsinwhichtheproductwill
humidity likely to affect performance of the product?
be used? Environment characteristics of interest typically
8.3.3.4 What is the range of conditions of the product in
include those that define the manner of use of the product and
use?Are there patterns of age, use, or abuse that will affect its
those that define nearby heat sources and other fuel items,
fire performance? Based on answers to questions like these,
nearbyoccupantsandtheircharacteristicsorbehaviors,andthe
how should the product specimen and its environment be
dimensions and characteristics of the spaces in which fire can
prepared for testing?
develop. In practical terms, the general-environment character-
istics of interest will generally be those that can be translated 8.4 Identify Measures Used to Calculate Fire Hazard—
into fire test specifications or variables in calculations. There are several measures that may be used to calculate fire
Typically, most or all of these environment characteristics can hazard (or fire risk, in accordance with Guide E1776). Each
be inferred from the (property) use groups or occupancy type of measure has advantages and disadvantages.
classifications where the product is to be used. Use groups and
8.4.1 Measures of End Outcomes, Such measures, including
occupancyclassificationssuitableforthispurposecanbefound
deaths, injuries, or property damage, are the most directly
in many codes and in coding rules for fire incident databases.
related to the ultimate concerns of fire impact on people and
property. This direct relationship is an advantage. However,
8.3.3.2 Whatdoesthisinformationandotherinformationon
these measures require the use of scenarios that specify not
the product’s environment indicate about the number of
only the product and its immediate environment but also the
persons or quantity and value of property that potentially could
entire building or occupancy and its occupants.As the analysis
be exposed to a fire involving the product, the special capa-
goes beyond the product’s immediate environment, it may
bilities or limitations of the occupants, and the special charac-
become more difficult to isolate differences between products,
teristics or vulnerabilities of the property? What does this
but this effect is real.
information indicate about the relative importance to overall
fire hazard of the particular fire-test response and other 8.4.1.1 An intermediate approach measures the arrival of a
characteristics selected in 8.3.2? particular fire condition, such as, reduced visibility, flashover,
(1) For example, for a product used in a small property, or insufficient oxygen, that may affect occupants and property.
such as, dwelling or store, the most important measures of its Thisapproachlackstherigorrequiredtoperformadirectdeath
involvement in a fire might include its ability to start a fire or damage analysis. However, it does set meaningful general
(ignitability) and the speed with which it produces hazardous criteria by which to judge products. When this intermediate
conditions(heatrelease,smoke-generationrate,profileoftoxic approach is used, the standard should clearly state that the
species produced). For a product used in a large property, like hazard assessment determines the arrival of particular fire
a high-rise hotel or office building, other measures of involve- conditions that do not necessarily relate to deaths and damage.
ment in fire might also be of interest, such as its ability to
8.4.2 Measures of Physical Fire Effects—Such measures,
produce hazardous conditions over a large area (flame-spread
including extent of flame or smoke damage or whether
rate, quantity of product in use, total heat released, total toxic
flashover occurs, are less directly and reliably related to the
product produced).
ultimate concerns of fire impact on people, property, or the
(2) As another example, for a product used in a densely
environment. However, most of these measures can be calcu-
populated property (for example, multifamily residential, pub-
lated with less elaborate estimation procedures, including
lic assembly) the measures of fire involvement of greatest
proceduresthatdonotcharacterizeoccupantsorspacesbeyond
concern might emphasize the product’s ability to produce the first room or area involved in a fire. This eliminates some
conditions hazardous to occupants (heat release, toxic species)
sources of uncertainty and makes it easier to isolate effects of
while for a product used in an industrial property, the measures
product differences, although the ultimate significance, to the
of greatest interest might emphasize the product’s ability to
end outcomes that are ultimately of concern, of the risk
produce fire effects that damage property that is either expen-
differences so identified may be less clear.
sive to replace or repair or critical to operation of the facility
8.4.3 Measures of Fire-Test-Response Characteristics—
(endurance under fire conditions, smoke corrosivity).
Such measures may be used individually or as elements in a
8.3.3.3 Environment—What is known about the immediate fire-characteristic profile. These measures come directly from
environment of the product as it affects the likely conditions of test methods, which may reduce their uncertainty, and tend to
theproduct’sinvolvementinfire?Istheproductalwayslocated be based on tests involving only the product, which may
in an exposed or enclosed space? What types of fire barriers simplify the process of isolating differences between products.
separate the product from other spaces (for example, an These are advantages of such profiles. However, the relative
ordinary wall, a fire-rated wall, an ordinary door that may be importance, interaction, and relevance of the fire-test-response
open,orafire-rateddoorwithautomaticclosingdevice)?Isthe characteristics, individually and collectively, to the hazard
product used in areas where building systems or other features posed by the product in real fires must be established by
such as, air-handling systems or open stairways, could contrib- comparison to more thorough assessments. The need for such
ute to transport of the product’s fire effects to remote parts of comparisons exists for all fire-hazard measures, but is greatest
E1546 − 21
for measures of fire-test-response characteristics, because they 8.5.1.2 The location of the ignition heat source and its
are farthest removed from end-outcome measures; this is a heat-release characteristics;
disadvantage of this approach.
8.5.1.3 Proximities and characteristics of other items near
8.4.4 A Fire-Characteristic Index is a measure that is
the first item ignited;
calculated from component fire-test-response characteristics or
8.5.1.4 Layout of the building or other environment, includ-
intrinsic fire properties. Such an index may make it easier to
ing the number of rooms and floors, room and other area
distinguish product differences, and because it integrates sev-
dimensions, and openings and vents between rooms and areas
eral fire-test-response characteristics, it may permit identifica-
and between rooms and the outside;
tion of simple evaluation criteria. These are advantages to this
8.5.1.5 Thermal properties of all room linings, fuel loads of
approach. Disadvantages include the need to demonstrate that
rooms and spaces other than the first room or area involved,
the index validly integrates the component characteristics,
properties and quantities of contents and finishes providing
which are likely to include the need for comparison of the
avenues of flame spread, and properties of barriers (doors,
index with results from large-scale tests and analyses of real
walls) and conditions required to breach them;
fires.
8.5.1.6 Number of persons, quantities and values of
8.4.5 Calculated Measures of End Outcomes are developed
property, and the locations and characteristics of people and
using equations to calculate measures of the type described in
property as they affect vulnerability and reaction to fire.
8.4.1 and 8.4.1.1 from input variables consisting of measures
8.5.2 For fire-risk assessments, in accordance with Guide
of the type described in 8.4.3.Afire model is an example of a
E1776, each scenario selected for analysis is linked to a
set of equations to perform such a calculation.
scenario class which it represents. Scenario classes are groups
8.4.6 Measures of Fire Risk (to be assessed by means of
of scenarios. The rules for grouping are normally such that
Guide E1776):
somecharacteristicsarespecifiedascommontoallscenariosin
8.4.6.1 Mean of Fire Hazard—The formula given in 6.1.3.4
the class, some characteristics are allowed to vary but only
defines fire risk as the mean value of fire hazard and is the
withinspecifiedranges,andsomecharacteristicsareallowedto
fire-risk measure used in most circumstances.
vary without limit (for example, if scenarios are defined by the
8.4.6.2 Probability of Hazard—An alternative measure de-
physical details of ignition, fires involving Class III B com-
fines fire risk as the probability that a specified level of fire
bustible liquids constitute a scenario class in which the type of
hazard will be met or exceeded. This measure can be used if a
material is precisely specified as a liquid, the flashpoint is
focusonhigh-severityoutcomesisconsideredappropriateorin
specified to within a range, and other characteristics, such as
circumstanceswherethemeasureoffireeffectisnotscalar(for
the heat source, are allowed to vary over all possibilities).
example, flashover occurs), which prevents the use of a mean
Probabilities can be estimated for scenario classes but are not
fire hazard definition of fire risk.
meaningful when calculated for fully specified scenarios.
8.4.6.3 Absolute versus Relative Risk—For any measure of
Because fire hazard is calculated for a scenario while probabil-
fire risk, it is possible to substitute a dimensionless measure
ity is calculated for the linked scenario class, it is important
that provides only the proportional change in fire risk from
that the scenario be a representative scenario for its scenario
some baseline. This choice removes some parts of the estima-
class. A representative scenario is an average scenario which
tion procedures, such as the need for estimates of the absolute
may not be the same as a typical scenario. Evidence should be
probability that fire will occur or for controversial assumptions
provided for each scenario class to support the implicit claim
such as dollar equivalent for a lost human life. If the threshold
that all scenarios included within that scenario class can be
foracceptableriskisdefinedbytheriskassociatedwithcurrent
accurately represented by a single design fire scenario. Evi-
products for the existing use or with products compliant with
dence also should be provided that the scenarios and scenario
current codes, then relative risk measures are likely to be
classes addressed by the fire-risk assessment method collec-
sufficient.
tively represent all scenarios in which the product can be
involved in fire with significant probability for significant
8.5 Identify and Describe Scenarios:
consequence.
8.5.1 A scenario is a detailed description of conditions,
including environmental, of one or more of the stages from 8.5.3 Because the focus of the assessment is a product, the
mostimportantscenariodimensionstypicallywillbethosethat
before ignition to the completion of combustion in an actual
fire. A fire scenario includes a set of details required to select either define the fire conditions that cause the product to
become involved in fire or indicate the point in the fire when
and specify test methods, fire model, or calculation procedure
the product’s contribution will have the greatest consequence
to produce one or more fire-hazard measures. The fire-hazard-
for hazard. To determine this, it is necessary to answer
assessment standard includes procedures to identify and de-
questions like these:
scribe scenarios, including procedures for selecting the sce-
narios to be used in the calculation. The standard can also 8.5.3.1 Is the product a likely first item ignited?Thismaybe
identify specific scenarios to include or represent in the
determined through analysis of historical fire experience if the
calculation. Typical characteristics used to define scenarios
product has been in use in the same manner for some time. If
include the following:
the answer is yes, the same analysis can indicate the relative
8.5.1.1 The location of the initial fuel for the fire, its importance of various types of initial heat sources such as:
fire-test-response characteristics, and its intrinsic fire proper- (1) Glowing hot object (lighted tobacco product, fireplace
ties; ember or spark, overloaded electrical wire).
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(2) Radiant-heat source (appliance designed to, or known theproduct’sabilitytogenerateasignificanthazardquickly,its
to, produce heat). total hazard capacity (for example, quantity in use), or the
(3) Open-flame source (match or lighter, torch, gas fueled persistence of its hazard during and after suppression opera-
burner or pilot light, fireplace fire, trash fire). tions. Such determinations can then be used to define test
(4) Accelerant-fed fire (arson fire set on the product with methods or calculation procedures that will measure the
use of accelerants). product’s contribution to fire hazard at those stages of the fire.
8.5.6 In particular, if the greatest concern with a product is
8.5.3.2 Is the product a potential major fuel source even if
not the first item ignited?Thismaybeestimatedbytherelative its ability to initiate fire or to produce by itself a rapid onset of
hazardous conditions, then it is most likely that test methods
quantity and total heat release of the product available for fire
involvement in rooms and areas where fire typically begins. If and calculation procedures need not explicitly address the
the answer is yes, then one might develop parameters for the product beyond its immediate environment or the specifics of
the population and property at risk. Thus, the analysis can be
heat source exposure to the product.
cut off at the immediate environment in this case, with little
8.5.3.3 Is the product a potential avenue of flame spread?
loss in validity and with reduced computation, if appropriate
This may be estimated from a review of large historical fires.
checks are incorporated. Conversely, if the greatest concerns
If the answer is yes, then one might specify testing of the
withtheproductarewithitscontributiontolargefiresexposing
product using a heat source considered to be representative of
remote populations or concentrations of value relatively late in
fire conditions for a well-de
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