EN ISO 13943:2010

SLOVENSKI STANDARD
01-januar-2011
1DGRPHãþD
SIST EN ISO 13943:2002
Požarna varnost - Slovar (ISO 13943:2008)
Fire safety - Vocabulary (ISO 13943:2008)
Brandschutz - Vokabular (ISO 13943:2008)
Sécurité au feu - Vocabulaire (ISO 13943:2008)
Ta slovenski standard je istoveten z: EN ISO 13943:2010
ICS:
01.040.13 Varstvo okolja in zdravja. Environment and health
Varnost (Slovarji) protection. Safety
(Vocabularies)
13.220.01 Varstvo pred požarom na Protection against fire in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 13943
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2010
ICS 01.040.13; 13.220.01 Supersedes EN ISO 13943:2000
English Version
Fire safety - Vocabulary (ISO 13943:2008)
Sécurité au feu - Vocabulaire (ISO 13943:2008) Brandschutz - Vokabular (ISO 13943:2008)
This European Standard was approved by CEN on 5 September 2010.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13943:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
The text of ISO 13943:2008 has been prepared by Technical Committee ISO/TC 92 “Fire safety” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 13943:2010 by
Technical Committee CEN/TC 127 “Fire safety in buildings” the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by March 2011, and conflicting national standards shall be withdrawn at
the latest by March 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 13943:2000.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 13943:2008 has been approved by CEN as a EN ISO 13943:2010 without any modification.

INTERNATIONAL ISO
STANDARD 13943
Second edition
2008-10-15
Fire safety — Vocabulary
Sécurité au feu — Vocabulaire
Reference number
ISO 13943:2008(E)
©
ISO 2008
ISO 13943:2008(E)
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©  ISO 2008
The reproduction of the terms and definitions contained in this International Standard is permitted in teaching manuals, instruction
booklets, technical publications and journals for strictly educational or implementation purposes. The conditions for such reproduction are:
that no modifications are made to the terms and definitions; that such reproduction is not permitted for dictionaries or similar publications
offered for sale; and that this International Standard is referenced as the source document.
With the sole exceptions noted above, no other part of this publication may be reproduced or utilized in any form or by any means,
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ii © ISO 2008 – All rights reserved

ISO 13943:2008(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Definition of the term “item” .1
4 Terms and definitions.1
Bibliography.41
Alphabetical index.42
Systematic index .46
Index of deprecated terms.51
ISO 13943:2008(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 13943 was prepared by Technical Committee ISO/TC 92, Fire safety, in cooperation with Technical
Committee IEC/TC 89, Fire hazard testing.
This second edition cancels and replaces the first edition (ISO 13943:2000), which has been technically
revised.
iv © ISO 2008 – All rights reserved

ISO 13943:2008(E)
Introduction
Over the last two decades, there has been significant growth in the subject field of fire safety. There has been
a considerable development of fire safety engineering design, especially as it relates to construction projects,
as well as the development of concepts related to performance-based design. With this continuing evolution,
there is an increasing need for agreement on a common language in the large domain of fire safety, beyond
what traditionally has been limited to the subject field of fire hazard testing.
The first edition of ISO 13943 contained definitions of about 180 terms. However, the area of technology that
is related to fire safety has continued to evolve rapidly and this second edition contains many new terms as
well as new definitions of some of the terms that were in the first edition.
This International Standard defines general terms to establish a vocabulary applicable to fire safety, including
fire safety in buildings and civil engineering works and other elements within the built environment. It will be
updated as terms and definitions for further concepts in the subject field of fire safety are agreed upon and
developed.
It is important to note that when used in legislation, some general fire safety terms have a narrower
interpretation and hence the definition given in this International Standard does not apply.
The terms in this International Standard are
— fundamental concepts, which may be the starting point for other, more specific, definitions,
— more specific concepts, used in several areas of fire safety such as fire testing and fire safety engineering
used in ISO and IEC fire standards, and
— related concept fields, designated by borrowed terms used in building and civil engineering.
The layout is in accordance with ISO 10241, unless otherwise specified. Thus, the elements of an entry
appear in the following order:
a) entry number;
b) preferred term(s);
c) admitted term(s);
d) deprecated term(s);
e) definition;
f) example(s);
g) note(s).
The terms are presented in English alphabetical order and are in bold type except for accepted but non-
preferred terms and deprecated terms, which are in normal type.
In a definition, example or note, reference to another entry in bold face is followed by the entry number in
brackets, when it is first mentioned.
Entry number, preferred term and definition are the mandatory elements of each entry. Other elements appear
only when appropriate.
Where a given term designates more than one concept, the concepts are listed in separate consecutive
entries and the terms individually numbered.
If the term has a general meaning but is being used in a specific subject field, that subject field is indicated in
angled brackets, 〈 〉, at the beginning of the definition.
Word class, e.g. “noun”, “adj.”, “verb”, is indicated if there is a risk of misunderstanding.
ISO 13943:2008(E)
Where the term describes a physical quantity, a note is given to indicate the typical units that are used (except
in cases where the unit is a single dimension such as mass, time or length).
Where a national variant in English is preferred or another equivalent exists, this has been given in bold face
following the preferred term and annotated by the respective country code. Where no other country code or
other equivalent is given in bold, this signifies that the preferred term is the accepted term in English-speaking
countries.
A term following the preferred term not given in boldface type is a non-preferred synonym.
To facilitate the location of any term given in this International Standard, irrespective of preference or country
of origin, the alphabetical index lists all preferred and non-preferred synonyms, without the respective country
code being indicated. There is also a systematic index and an index of deprecated terms.

vi © ISO 2008 – All rights reserved

INTERNATIONAL STANDARD ISO 13943:2008(E)

Fire safety — Vocabulary
1 Scope
This International Standard defines terminology relating to fire safety as used in International Standards and
other documents of the International Standardization Organization and the International Electrotechnical
Committee.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 6707-1:2004, Building and civil engineering — Vocabulary — Part 1: General terms
ISO 10241:1992, International terminology standards — Preparation and layout
3 Definition of the term “item”
For the purposes of this International Standard, the English term “item” is used in a general meaning to
represent any single object or assembly of objects, and may cover, for example, material, product, assembly,
structure or building, as required in the context of any individual definition.
If the “item” under consideration is a test specimen then the term “test specimen” is used.
4 Terms and definitions
4.1
abnormal heat
〈electrotechnical〉 heat that is additional to that resulting from use under normal conditions, up to and including
that which causes a fire (4.96)
4.2
acceptance criteria
criteria that form the basis for assessing the acceptability of the safety of a design of a built
environment (4.26)
NOTE The criteria can be qualitative, quantitative or a combination of both.
4.3
activation time
time interval from response by a sensing device until the suppression system (4.314), smoke control
system, alarm system or other fire safety system is fully operational
ISO 13943:2008(E)
4.4
actual delivered density
ADD
volumetric flow rate of water per unit area that is delivered onto the top horizontal surface of a simulated
burning combustible (4.43) array
NOTE 1 It is typically determined relative to a specific heat release rate (4.177) of a fire (4.98).
NOTE 2 ADD can be measured as described in ISO 6182-7.
−1
NOTE 3 The typical units are millimetres per minute (mm⋅min ).
4.5
acute toxicity
toxicity (4.341) that causes rapidly occurring toxic (4.335) effects
cf. toxic potency (4.338)
4.6
afterflame
flame (4.133) that persists after the ignition source (4.189) has been removed
4.7
afterflame time
length of time for which an afterflame (4.6) persists under specified conditions
cf. duration of flaming (4.71)
4.8
afterglow
persistence of glowing combustion (4.169) after both removal of the ignition source (4.189) and the
cessation of any flaming combustion (4.148)
4.9
afterglow time
length of time during which an afterglow (4.8) persists under specified conditions
4.10
agent outlet
orifice of a piping system by means of which an extinguishing fluid can be applied towards the source of a
fire (4.98)
4.11
alarm time
time interval between ignition (4.187) of a fire (4.98) and activation of an alarm
NOTE The time of ignition can be known, e.g. in the case of a fire model (4.116) or a fire test (4.132), or it may be
assumed, e.g. it may be based upon an estimate working back from the time of detection. The basis on which the time of
ignition is determined is always stated when the alarm time is specified.
4.12
alight, adj.
lit, adj. CA, US
lighted, adj.
undergoing combustion (4.46)
2 © ISO 2008 – All rights reserved

ISO 13943:2008(E)
4.13
arc resistance
〈electrotechnical〉 ability of an electrically insulating material to resist the influence of an electric arc, under
specified conditions
NOTE The arc resistance is identified by the length of the arc, the absence or presence of a conducting path and the
burning or damage of the test specimen (4.321).
4.14
area burning rate
burning rate (deprecated)
rate of burning (deprecated)
area of material burned (4.28) per unit time under specified conditions
2 −1
NOTE The typical units are square metres per second ( m ⋅s ).
4.15
arson
crime of setting a fire (4.98), usually with intent to cause damage
4.16
ash
ashes
mineral residue resulting from complete combustion (4.50)
4.17
asphyxiant
toxicant (4.340) that causes hypoxia, which can result in central nervous system depression or
cardiovascular effects
NOTE Loss of consciousness and ultimately death can occur.
4.18
auto-ignition
spontaneous ignition
self-ignition CA, US
unpiloted ignition CA, US
spontaneous combustion (deprecated)
ignition (4.187) resulting from a rise of temperature without a separate ignition source (4.189)
NOTE 1 The ignition can be caused either by self-heating (4.287, 4.288) or by heating from an external source.
NOTE 2 In North America, “spontaneous ignition” is the preferred term used to designate ignition caused by self-
heating.
4.19
auto-ignition temperature
spontaneous ignition temperature
minimum temperature at which auto-ignition (4.18) is obtained in a fire test (4.132)
NOTE The typical units are degrees Celsius (°C).
4.20
available safe escape time
ASET
time available for escape
for an individual occupant, the calculated time interval between the time of ignition (4.187) and the time at
which conditions become such that the occupant is estimated to be incapacitated, i.e. unable to take effective
action to escape (4.82) to a safe refuge (4.280) or place of safety (4.253)
ISO 13943:2008(E)
NOTE 1 The time of ignition can be known, e.g. in the case of a fire model (4.116) or a fire test (4.132), or it may be
assumed, e.g. it may be based upon an estimate working back from the time of detection. The basis on which the time of
ignition is determined is always stated.
NOTE 2 This definition equates incapacitation (4.194) with failure to escape. Other criteria for ASET are possible. If an
alternate criterion is selected, it is necessary that it be stated.
NOTE 3 Each occupant can have a different value of ASET, depending on that occupant’s personal characteristics.
4.21
backdraft
rapid flaming combustion (4.148) caused by the sudden introduction of air into a confined oxygen-deficient
space that contains hot products of incomplete combustion (4.46)
NOTE In some cases, these conditions can result in an explosion (4.87).
4.22
behavioural scenario
description of the behaviour of occupants during the course of a fire (4.98)
4.23
black body
form that completely absorbs any electromagnetic radiation falling upon it
4.24
black-body radiant source
radiant source that produces electromagnetic radiation as described by Planck's distribution function
NOTE The emissivity (4.75) of a black body radiant source is unity.
4.25
building element
integral part of a built environment (4.26)
NOTE 1 This includes floors, walls, beams, columns, doors, and penetrations, but does not include contents.
NOTE 2 This definition is wider in its scope than that given in ISO 6707-1.
4.26
built environment
building or other structure
EXAMPLES Off-shore platforms; civil engineering works, such as tunnels, bridges and mines; and means of
transportation, such as motor vehicles and marine vessels.
NOTE ISO 6707-1 contains a number of terms and definitions for concepts related to the built environment.
4.27
buoyant plume
convective updraft of fluid above a heat source
cf. fire plume (4.118)
4.28
burn, intransitive verb
undergo combustion (4.46)
4.29
burn, transitive verb
cause combustion (4.46)
4 © ISO 2008 – All rights reserved

ISO 13943:2008(E)
4.30
burned area
that part of the damaged area (4.59) of a material that has been destroyed by combustion (4.46) or
pyrolysis (4.266), under specified conditions
NOTE The typical units are square metres (m ).
4.31
burned length
maximum extent in a specified direction of the burned area (4.30)
NOTE The typical units are metres (m).
cf. damaged length (4.60)
4.32
burning behaviour
〈fire tests〉 response of a test specimen (4.321), when it burns under specified conditions, to examination of
reaction to fire (4.272) or fire resistance (4.121)
4.33
bursting
violent rupture of an object due to an overpressure within it or upon it
4.34
calibration
〈fire modelling〉 process of adjusting modelling parameters in a computational model for the purpose of
improving agreement with experimental data
4.35
calorimeter
apparatus that measures heat
cf. heat release rate calorimeter (4.178) and mass calorimeter (4.219).
4.36
carboxyhaemoglobin saturation
percentage of blood haemoglobin converted to carboxyhaemoglobin from the reversible reaction with inhaled
carbon monoxide
4.37
ceiling jet
gas motion in a hot gas layer near a ceiling that is generated by the buoyancy of a fire plume (4.118) that is
impinging upon the ceiling
4.38
char, noun
carbonaceous residue resulting from pyrolysis (4.266) or incomplete combustion (4.46)
4.39
char, verb
form char (4.38)
4.40
char length
length of charred area
cf. burned length (4.31) and damaged length (4.60)
NOTE In some standards, char length is defined by a specific test method.
ISO 13943:2008(E)
4.41
chimney effect
upward movement of hot fire effluent (4.105) caused by convection (4.54) currents confined within an
essentially vertical enclosure (4.77)
NOTE This usually draws more air into the fire (4.96).
4.42
clinker
solid agglomerate of residues formed by either complete combustion (4.50) or incomplete
combustion (4.46) and which can result from complete or partial melting
4.43
combustible, adj.
capable of being ignited (4.186) and burned
4.44
combustible, noun
item capable of combustion (4.46)
4.45
combustible load
theoretical mass that would be lost from a test specimen (4.321) if it were to undergo complete
combustion (4.50) in a fire test (4.132)
4.46
combustion
exothermic reaction of a substance with an oxidizing agent (4.246)
NOTE Combustion generally emits fire effluent (4.105) accompanied by flames (4.133) and/or glowing (4.168).
4.47
combustion efficiency
ratio of the amount of heat release (4.176) in incomplete combustion (4.46) to the theoretical heat of
complete combustion (4.50)
NOTE 1 Combustion efficiency can be calculated only for cases where complete combustion can be defined.
NOTE 2 Combustion efficiency is dimensionless and is usually expressed as a percentage.
4.48
combustion product
product of combustion
solid, liquid and gaseous material resulting from combustion (4.46)
NOTE Combustion products can include fire effluent (4.105), ash (4.16), char (4.38), clinker (4.42) and/or
soot (4.298).
4.49
common mode failure
failure involving a single source that affects more than one type of safety system simultaneously
4.50
complete combustion
combustion (4.46) in which all the combustion products (4.48) are fully oxidized
NOTE 1 This means that, when the oxidizing agent (4.246) is oxygen, all carbon is converted to carbon dioxide and all
hydrogen is converted to water.
NOTE 2 If elements other than carbon, hydrogen and oxygen are present in the combustible (4.43) material, those
elements are converted to the most stable products in their standard states at 298 K.
6 © ISO 2008 – All rights reserved

ISO 13943:2008(E)
4.51
composite material
structured combination of two or more discrete materials
4.52
concentration
mass per unit volume
−3
NOTE 1 For a fire effluent (4.105) the typical units are grams per cubic metre (g⋅m ).
NOTE 2 For a toxic gas (4.336), concentration is usually expressed as a volume fraction (4.351) at T = 298 K and
3 3 −6
P = 1 atm, with typical units of microlitres per litre (µL/L), which is equivalent to cm /m or 10 .
NOTE 3 The concentration of a gas at a temperature, T, and a pressure, P can be calculated from its volume
fraction (assuming ideal gas behaviour) by multiplying the volume fraction by the density of the gas at that temperature
and pressure.
4.53
concentration-time curve
〈toxicology〉 plot of the concentration (4.52) of a toxic gas (4.336) or fire effluent (4.105) as a function of
time
−3
NOTE 1 For fire effluent, concentration is usually measured in units of grams per cubic metre (g⋅m ).
NOTE 2 For a toxic gas, concentration is usually expressed as a volume fraction (4.351) at T = 298 K and P = 1 atm,
3 3 −6
with typical units of microlitres per litre (µL/L), which is equivalent to cm /m or 10 .
4.54
convection
transfer of heat by movement of a fluid
4.55
convective heat flux
heat flux (4.173) caused by convection (4.54)
4.56
corrosion damage
physical and/or chemical damage or impaired function caused by chemical action
4.57
corrosion target
sensor used to determine the degree of corrosion damage (4.56), under specified conditions
NOTE The sensor may be a product or a component. It may also be a reference material or object used to simulate the
behaviour of a product or a component.
4.58
critical fire load
fire load (4.114) required in a fire compartment (4.102) to produce a fire (4.98) of sufficient severity to cause
failure of a fire barrier(s) (4.99) or structural member(s) located within or bounding the fire compartment
4.59
damaged area
total of those surface areas that have been affected permanently by fire (4.97) under specified conditions
cf. burned area (4.30)
NOTE 1 Users of this term should specify the types of damage to be considered. This can include, for example, loss of
material, deformation, softening, melting behaviour (4.228), char (4.38) formation, combustion (4.46), pyrolysis (4.266)
or chemical attack.
NOTE 2 The typical units are square metres (m ).
ISO 13943:2008(E)
4.60
damaged length
maximum extent in a specified direction of the damaged area (4.59)
cf. char length (4.40) and burned length (4.31)
4.61
defend in place
life safety strategy in which occupants are encouraged to remain in their current location rather than to attempt
escape (4.82) during a fire (4.98)
4.62
deflagration
combustion (4.46) wave propagating at subsonic velocity
NOTE If within a gaseous medium, deflagration is the same as a flame (4.133).
4.63
design density
measured volumetric flow rate of water from sprinklers, per unit area, that is delivered in the absence of a
fire (4.98)
−1
NOTE The typical units are millimetres per minute (mm⋅min ).
4.64
design fire
quantitative description of assumed fire (4.98) characteristics within the design fire scenario (4.65)
NOTE It is, typically, an idealized description of the variation with time of important fire (4.98) variables, such as heat
release rate (4.177), flame spread rate (4.143), smoke production rate (4.295), toxic gas (4.336) yields (4.354), and
temperature.
4.65
design fire scenario
specific fire scenario (4.129) on which a deterministic fire-safety engineering (4.126) analysis is conducted
4.66
detection time
time interval between ignition (4.187) of a fire (4.98) and its detection by an automatic or manual system
4.67
deterministic model
fire model (4.116) that uses science-based mathematical expressions to produce the same result each time
the method is used with the same set of input data values
4.68
detonation
reaction characterized by a shock wave propagating at a velocity greater than the local speed of sound in the
unreacted material
4.69
diffusion flame
flame (4.133) in which combustion (4.46) occurs in a zone where the fuel (4.161) and the oxidizing
agent (4.246) mix, having been initially separate
cf. pre-mixed flame (4.259)
8 © ISO 2008 – All rights reserved

ISO 13943:2008(E)
4.70
draught-free environment
space in which the results of experiments are not significantly affected by the local air speed
NOTE A qualitative example is a space in which a wax candle flame (4.133) remains essentially undisturbed.
−1 −1
Quantitative examples are small-scale fire tests (4.292) in which a maximum air speed of 0,1 m⋅s or 0,2 m⋅s is
sometimes specified.
4.71
duration of flaming
length of time for which flaming combustion (4.148) persists under specified conditions
cf. afterflame time (4.7)
4.72
effective concentration 50
EC
concentration (4.52) of a toxic gas (4.336) or fire effluent (4.105), statistically calculated from
concentration-response data, that causes a specified effect in 50 % of a population of a given species within a
specified exposure time (4.90) and post-exposure time (4.254)
cf. IC (4.181)
−3
NOTE 1 For fire effluent, typical units are grams per cubic metre (g⋅m ).
NOTE 2 For a toxic gas, typical units are microlitres per litre (µL/L) (at T = 298 K and P = 1 atm); see volume
fraction (4.351).
NOTE 3 The observed effect is usually a behavioural response, incapacitation (4.194), or death. The EC for
incapacitation is termed the IC (4.181). The EC for lethality is termed the LC (4.207).
50 50 50
4.73
effective exposure dose 50
ECt
product of EC (4.72) and the exposure time (4.90) over which it is determined
cf. exposure dose (4.89)
−3
NOTE 1 For fire effluent (4.105), typical units are grams times minutes per cubic metre (g⋅min⋅m ).
−1
NOTE 2 For a toxic gas (4.336), typical units are microlitres times minutes per litre (µL⋅min⋅L ) (at T = 298 K and
P = 1 atm); see volume fraction (4.351).
NOTE 3 ECt is a measure of toxic potency (4.338).
4.74
effective heat of combustion
heat released (4.176) from a burning test specimen (4.321) in a given time interval divided by the mass lost
from the test specimen in the same time period
NOTE 1 It is the same as the net heat of combustion (4.237) if all the test specimen is converted to volatile
combustion (4.46) products and if all the combustion products (4.48) are fully oxidized.
−1
NOTE 2 The typical units are kilojoules per gram (kJ⋅g ).
4.75
emissivity
ratio of the radiation emitted by a radiant source to the radiation that would be emitted by a black body
radiant source (4.24) at the same temperature
NOTE Emissivity is dimensionless.
ISO 13943:2008(E)
4.76
empirical formula
chemical formula of a substance in which the relative numbers of atoms of each type are given
NOTE Typically, the number for one type of atom (usually C or O) is chosen to be an integer; e.g., a particular sample
can be represented as C H O N Cl .
6 8,9 4,1 0,3 0,01
4.77
enclosure
〈built environment〉 volume defined by bounding surfaces, which may have one or more openings
4.78
enclosure
〈electrotechnical〉 external casing protecting the electrical and mechanical parts of apparatus
NOTE The term excludes cables.
4.79
end-use condition
intended condition to which an item is subjected during its normal working life, when used in accordance with
the manufacturer's instructions
4.80
environment
conditions and surroundings that can influence the behaviour of an item or persons when exposed to
fire (4.98)
4.81
equivalence ratio
fuel (4.161)/air ratio divided by the fuel/air ratio required for a stoichiometric mixture (4.309)
cf. fuel-lean combustion (4.162), fuel-rich combustion (4.163), stoichiometric combustion (4.308), and
stoichiometric mixture (4.309)
NOTE 1 Standard, dry air contains 20,95 % oxygen by volume. In practice, the oxygen concentration (4.52) in
entrained air can vary and a calculation of the equivalence ratio to a standard, dry air basis is required.
NOTE 2 The equivalence ratio is dimensionless.
4.82
escape
effective action taken to reach a safe refuge (4.280) or place of safety (4.253)
4.83
evacuation behaviour
behaviour which enables occupants of a building to reach a place of safety (4.253)
cf. movement behaviour (4.233) and pre-movement behaviour (4.260)
4.84
evacuation time
time interval between the time of a warning of fire (4.98) being transmitted to the occupants and the time at
which the occupants of a specified part of a building or all of the building are able to enter a place of
safety (4.253)
cf. available safe escape time (4.20)
4.85
event tree
depiction of temporal, causal sequences of events, built around a single initiating condition
10 © ISO 2008 – All rights reserved

ISO 13943:2008(E)
4.86
exit
designated point of departure from a building
4.87
explosion
〈chemical〉 abrupt expansion of gas that can result from a rapid oxidation (4.245) or decomposition reaction,
with or without an increase in temperature
4.88
exposed surface
surface of a test specimen (4.321) subjected to the heating conditions of a fire test (4.132)
4.89
exposure dose
measure of the maximum amount of a toxic gas (4.336) or fire effluent (4.105) that is available for inhalation,
calculated by integration of the area under a concentration-time curve (4.53)
−3
NOTE 1 For fire effluent, typical units are grams times minutes per cubic metre (g⋅min⋅m ).
−1
NOTE 2 For a toxic gas, typical units are microlitres times minutes per litre (µL⋅min⋅L ) (at T = 298 K and P = 1 atm);
see volume fraction (4.351).
4.90
exposure time
length of time for which people, animals or test specimens (4.321) are exposed under specified conditions
4.91
extent of combustion
〈electrotechnical〉 maximum length of a test specimen (4.321) that has been destroyed by combustion (4.46)
or pyrolysis (4.266), under specified test conditions, excluding any region damaged only by deformation
4.92
extinction area of smoke
product of the volume occupied by smoke (4.293) and the extinction coefficient (4.93) of the smoke
NOTE It is a measure of the amount of smoke, and the typical units are square metres (m ).
4.93
extinction coefficient
natural logarithm of the ratio of incident light intensity to transmitted light intensity, per unit light path length
−1
NOTE Typical units are reciprocal metres (m ).
4.94
F factor
minimum concentration (4.52) of a toxic gas (4.336) irritant (4.203, 4.204) that is expected to seriously
compromise the ability to escape (4.82) from a fire (4.98)
cf. fractional effective concentration (4.159)
NOTE The concentration is usually expressed as a volume fraction (4.351) at T = 298 K and P = 1 atm, in which case
3 3 −6
the typical units are microlitres per litre (µL/L), which is equivalent to cm /m or 10 .
4.95
fault tree
depiction of the logical dependencies of events on one another, built around a critical resulting event, which
usually has an unacceptable level of consequence and may be described as a failure
ISO 13943:2008(E)
4.96
fire
〈general〉 process of combustion (4.46) characterized by the emission of heat and fire effluent (4.105) and
usually accompanied by smoke (4.293), flame (4.133), glowing (4.168) or a combination thereof
NOTE In the English language the term “fire” is used to designate three concepts, two of which, fire (4.97) and
fire (4.98), relate to specific types of self-supporting combustion with different meanings and two of them are designated
using two different terms in both French and German.
4.97
fire
〈controlled〉 self-supporting combustion (4.46) that has been deliberately arranged to provide useful effects
and is limited in its extent in time and space
4.98
fire
〈uncontrolled〉 self-supporting combustion (4.46) that has not been deliberately arranged to provide useful
effects and is not limited in its extent in time and space
4.99
fire barrier
fire separation, noun CA
separating element (4.291) that exhibits fire integrity (4.113) or fire stability (4.131) or thermal
insulation (4.328), or a combination thereof, for a period of time under specified conditions
4.100
fire behaviour
change in, or maintenance of, the physical and/or chemical properties of an item and/or structure exposed to
fire (4.96)
cf. fire performance (4.117)
NOTE 1 This concept covers both reaction to fire (4.272) and fire resistance (4.121).
NOTE 2 In English, this term may also be used to describe the behaviour of a fire (4.96).
4.101
fire classification
standardized system of classifying fires (4.96) in terms of the nature of the fuel (4.161)
EXAMPLE In Europe and Australasia there are six classes:
— Class A: fire involving solid materials, usually of an organic nature, in which combustion (4.46) normally takes place
with the formation of glowing (4.168) embers;
— Class B: fires involving liquids or liquefiable solids;
— Class C: fires involving gases;
— Class D: fires involving metals;
— Class E: fires involving electrical hazards;
— Class F: fires involving cooking oil or fat.
4.102
fire compartment
enclosed space, which may be subdivided, separated from adjoining spaces by fire barriers (4.99)
4.103
fire danger
concept including both fire hazard (4.112) and fire risk (4.124)
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ISO 13943:2008(E)
4.104
fire decay
stage of fire development after a fire (4.96) has reached its maximum intensity and during which the heat
release rate (4.177) and the temperature of the fire are decreasing
4.105
fire effluent
totality of gases and aerosols, including suspended particles, created by combustion (4.46) or
pyrolysis (4.266) in a fire (4.96)
4.106
fire-effluent decay characteristic
physical and/or chemical change in fire effluent (4.105) caused by ageing and transport
4.107
fire-effluent transport
movement of fire effluent (4.105) from the location of a fire (4.96)
4.108
fire exposure
extent to which persons, animals or items are subjected to the conditions created by fire (4.96)
4.109
fire extinguishment
process that eliminates combustion (4.46)
4.110
fire gases
gaseous part of combustion product(s) (4.48)
cf. fire effluent (4.105)
NOTE In French, the term “gaz de combustion” also applies to engine exhaust gas and can then include particles.
4.111
fire growth
stage of fire (4.96) development during which the heat release rate (4.177) and the temperature of the fire
are increasing
4.112
fire hazard
physical object or condition with a potential for an undesirable consequence from fire (4.98)
4.113
fire integrity
integrity CA, US
ability of a separating element (4.291), when exposed to fire (4.97) on one side, to prevent the passage of
flame(s) (4.133) and hot gases or the occurrence of flames on the unexposed side for a stated period of time
in a standard fire resistance (4.121) test
cf. integrity criterion “E” (4.199)
4.114
fire Ioad
quantity of heat which can be released by the complete combustion (4.50) of all the combustible (4.43)
materials in a volume, including the facings of all bounding surfaces
NOTE 1 Fire load may be based on effective heat of combustion (4.74), gross heat of combustion (4.170), or net
heat of combustion (4.237) as required by the specifier.
ISO 13943:2008(E)
NOTE 2 The word “load” can be used to denote force or power or energy. In this context, it is being used to denote
energy.
NOTE 3 The typical units are kilojoules (kJ) or megajoules (MJ).
4.115
fire load density
fire load (4.114) per unit area
−2
NOTE The typical units are kilojoules per square metre (kJ⋅m ).
4.116
fire model
fire simulation
calculation method that describes a system or process related to fire (4.96) development, including fire
dynamics and the effects of fire
cf. deterministic model (4.67), numerical fire model (4.241), physical fire model (4.251) and probabilistic
model (4.264)
4.117
fire performance
response of a test specimen (4.321) when exposed to a fire test (4.132)
cf. fire behaviour (4.100)
4.118
fire plume
plume
buoyant gas stream and any materials transported within it, above a fire (4.96)
cf. buoyant plume (4.27)
4.119
fire point
minimum temperature at which a material ignites (4.184) and continues to burn (4.28) for a specified time
after a standardized small flame (4.133) has been applied to its surface under specified conditions
cf. flash point (4.154)
NOTE 1 In some countries, the term “fire point” has an additional meaning: a location where fire-fighting equipment is
sited, which may also comprise a fire-alarm call point and fire instruction notices.
NOTE 2 The typical units are degrees Celsius (°C).
4.120
fire propagation
combination of flame spread (4.142) and spread of fire effluent (4.105)
4.121
fire resistance
ability of a test specimen (4.321) to withstand fire (4.97) or give protection from it for a period of time
NOTE 1 Typical criteria used to assess fire resistance in a standard fire test (4.132) are fire integrity (4.113), fire
stability (4.131), and thermal insulation material (4.327).
NOTE 2 “Fire-resistant” (adj.) refers only to this ability.
4.122
fire retardance (deprecated)
cf. flame retardance (4.138), fire retardant (4.123) and flame retardant (4.139)
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ISO 13943:2008(E)
4.123
fire retardant, noun
substance added, or a treatment applied, to a material in order to delay ignition (4.187) or to reduce the rate
of combustion (4.46)
cf. flame retardant (4.139)
NOTE The use of (a) fire retardant(s) does not necessarily suppress fire (4.96) or terminate combustion.
4.124
fire risk
probability of a fire (4.98) combined with a quantif
...