IEC TR 62222:2021

IEC TR 62222 ®
Edition 3.0 2021-01
TECHNICAL
REPORT
Fire performance of communication cables installed in buildings

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IEC TR 62222 ®
Edition 3.0 2021-01
TECHNICAL
REPORT
Fire performance of communication cables installed in buildings

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.220.40; 33.120.20 ISBN 978-2-8322-9240-2

– 2 – IEC TR 62222:2021 © IEC 2021
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 16
4 Communications cabling in buildings . 16
4.1 Installations and associated fire danger . 16
4.2 Mitigation of fire hazards . 18
5 Fire hazard . 19
5.1 Fire hazard considerations . 19
5.2 Performance assessment . 21
6 Test methods . 23
6.1 Review . 23
6.2 NFPA 262 . 23
6.3 EN 50399 . 24
6.4 IEC 60332-3 (all parts) . 24
6.5 UL 1666 . 25
6.6 UL 1685 and CSA FT4 . 25
6.7 Other considerations . 26
6.8 Test method conclusions. 26
7 Fire performance . 27
7.1 Parameters . 27
7.2 Heat . 27
7.3 Effluent smoke . 28
7.4 Propagation . 29
7.5 Ignitability . 29
7.6 Damaging effects of fire effluents . 29
7.7 Flaming droplets . 29
7.8 Toxicity . 29
8 Legislation and regulation examples . 29
Annex A (informative) Typical communication cable installations . 32
Annex B (informative) Fire hazards/installations/applications/test methods for
communication cables in buildings . 33
Annex C (informative) Review of test methods . 34
Annex D (informative) Fire performance requirements . 40
Annex E (informative) Recent project for regulation – The FIPEC project . 41
Bibliography . 42

Figure A.1 – Typical installation locations . 32

Table 1 – Traditional ranking of fire hazards . 18
Table 2 – Cable fire performance test methods . 23

Table 3 – Severity . 23
Table 4 – Examples of materials for communication cables . 28
Table 5 – Heat requirements of EN 13501-6 . 28
Table 6 – Smoke requirements comparisons . 29
Table 7 – Class structure of EN 13501-6 . 30
Table B.1 – Fire hazards/installations/applications/test methods for communication
cables in buildings . 33
Table C.1 – Ignitability . 34
Table C.2 – Vertical tests . 35
Table C.3 – Horizontal tests for forced air systems . 38
Table C.4 – Indirect measurement of smoke . 39
Table D.1 – Fire performance requirements . 40
Table D.2 – Single cable burn test . 40

– 4 – IEC TR 62222:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIRE PERFORMANCE OF COMMUNICATION
CABLES INSTALLED IN BUILDINGS
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
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preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
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Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC TR 62222 has been prepared by subcommittee 46C: Wires and symmetric cables, of IEC
technical committee 46: Cables, wires, waveguides, RF connectors, RF and microwave passive
components and accessories. It is a Technical Report.
This third edition cancels and replaces the second edition published in 2012. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Scope rewritten to clarify and bring into line current understanding from other technical
sources;
b) Normative References updated to be in line with the most recent technical definitions and
new additions;
c) new additional terms and definitions added to Annex F since these are not used in the
document;
d) new inclusions to the list of abbreviated terms, some corrections;
e) project reports are now in Annex E, for information only;

f) Subclause 4.2 Mitigation of fire hazards, about fire protection, updated with clearer
information on standards plus updates where new standards have been published or
amended;
g) test methods, test methods conclusions and fire performance updated.
The text of this Technical Report is based on the following documents:
DTR Report on voting
46C/1151/DTR 46C/1156/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC TR 62222:2021 © IEC 2021
INTRODUCTION
IEC TR 62222:2005 was the first attempt in understanding the potential fire hazards concerning
new installations where large quantities of data cable are involved. Although it is important to
remember that data cables will probably not spontaneously combust and offices are still filled
with other highly flammable products, the increase of "flood wiring" should be a building design
concern. IEC TR 62222:2012 attempted to align all the installation guides found and further
improve safety with fire and its possible transmission.

FIRE PERFORMANCE OF COMMUNICATION
CABLES INSTALLED IN BUILDINGS
1 Scope
This document describes the test methods for various parameters relating to the reaction to fire
properties of metallic and optical fibre communications cables. The parameters have particular
importance for cables intended to be installed within buildings and other structures.
This document also maps the test methods and associated limits applied to the fire hazards
created by particular installation conditions and which can be referenced by other international,
regional and national standards. For example, it is important that compliance with the
requirements and recommendations for installation methods in ISO/IEC 14763-2 taking into
consideration this document improve safety concerning fire.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms, definitions and abbreviated terms apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
asphyxiant
toxicant that causes hypoxia, which can result in central nervous system depression or
cardiovascular effects
[SOURCE: ISO 13943:2017, 3.23, modified – The note to entry has been removed.]
3.1.2
cabling
system of telecommunication cables, cords and connecting hardware that supports the
connection of information technology equipment
[SOURCE: ISO/IEC 11801-1:2017, 3.1.21]
3.1.3
chimney effect
upward movement of hot fire effluent caused by convection currents confined within an
essentially vertical enclosure
[SOURCE: ISO 13943:2017, 3.50, modified – The note to entry has been removed.]

– 8 – IEC TR 62222:2021 © IEC 2021
3.1.4
combustible
capable of being ignited and burned
[SOURCE: ISO 13943:2017, 3.52]
3.1.5
combustion
exothermic reaction of a substance with an oxidizing agent
Note 1 to entry: Combustion generally emits fire effluent accompanied by flames and/or glowing.
[SOURCE: ISO 13943:2017, 3.55]
3.1.6
communication cable
assembly of suitably insulated coaxial conductors, twisted pairs of insulated conductors or
optical fibres fabricated to meet transmission, mechanical and environmental requirements, and
sufficient to allow conveyance of information between two points with the minimum of radiation
3.1.7
compartment
discrete fire zone designed to contain a fire within that zone
Note 1 to entry: Compartments are also known as "fire compartments".
3.1.8
compartmentation
division of premises into compartments in order to provide protection for the rest of the premises
3.1.9
convection
transfer of heat by movement of a fluid
[SOURCE: ISO 13943:2017, 3.66]
3.1.10
contribution to fire
energy released by a product influencing the fire growth
3.1.11
corrosion damage
physical and/or chemical damage or impaired function caused by chemical action
[SOURCE: ISO 13943:2017, 3.69]
3.1.12
damaged length
maximum extent in a specified direction of damaged area
3.1.13
enclosure
volume defined by bounding surfaces, which may have one or more
openings
[SOURCE: ISO 13943:2017, 3.92]

3.1.14
fire
process of combustion characterized by the emission of heat and fire effluent and
usually accompanied by smoke, flame or glowing or a combination thereof
Note 1 to entry: In the English language, the term "fire" is used to designate three concepts, two of which relate to
specific types of self-supporting combustion with different meanings. Of these three, two of them are designated
using two different terms in both French and German.
[SOURCE: ISO 13943:2017, 3.114]
3.1.15
fire attack
thermal attack by fire test burner
3.1.16
fire compartment
enclosed space, which may be subdivided, separated from adjoining spaces by fire barriers
[SOURCE: ISO 13943:2017, 3.120]
3.1.17
fire danger
concept including both fire hazard and fire risk
[SOURCE: ISO 13943:2017, 3.121, modified – The note to entry has been removed.]
3.1.18
fire effluent
totality of gases and aerosols, including suspended particles, created by combustion or
pyrolysis in a fire
[SOURCE: ISO 13943:2017, 3.123, modified – The definition has been rephrased.]
3.1.19
fire growth
stage of fire development during which the heat release rate and the temperature of the fire are
increasing
[SOURCE: ISO 13943:2017, 3.129]
3.1.20
fire growth rate index
FIGRA index
highest value of the quotient between heat release rate (HRR) and time
Note 1 to entry: In this report FIGRA is expressed in W/s.
3.1.21
fire hazard
potential for harm associated with fire
Note 1 to entry: Alternatively, fire hazard can be a physical object or condition with a potential for an undesirable
consequence from fire.
[SOURCE: ISO 13943:2017, 3.131]

– 10 – IEC TR 62222:2021 © IEC 2021
3.1.22
fire load
quantity of heat which could be released by the complete combustion of all the combustible
materials in a volume, including the facings and bounding surfaces
Note 1 to entry: Fire load may be based on effective heat of combustion, gross heat of combustion, or net heat of
combustion as required by the specifier.
[SOURCE: ISO 13943:2017, 3.134, modified – Note 2 to entry and Note 3 to entry have been
removed.]
3.1.23
fire performance
response of a material, product or assembly in a fire
[SOURCE: ISO 13943:2017, 3.137, modified – The notes to entry have been removed.]
3.1.24
fire propagation
combination of flame spread and spread of fire effluent
[SOURCE: ISO 13943:2017, 3.140]
3.1.25
fire resistance
ability of a test specimen to withstand fire or give protection from it for a period of time
Note 1 to entry: Typical criteria used to asses fire resistance in a standard fire test are fire integrity, fire stability
and thermal insulation.
[SOURCE: ISO 13943:2017, 3.141, modified – Note 2 to entry has been removed.]
3.1.26
fire risk
estimation of expected fire loss that combines the potential for harm in various fire scenarios
that can occur with the probabilities of occurrence of those scenarios
Note 1 to entry: An alternate definition of fire risk is, "combination of the probability of a fire and a quantified
measure of its consequence".
Note 2 to entry: Fire risk is often calculated as the product of probability and consequence.
[SOURCE: ISO 13943:2017, 3.145]
3.1.27
fire scenario
qualitative description of the course of a fire with respect to time, identifying key events that
characterize the studied fire and differentiate it from other possible fires
[SOURCE: ISO 13943:2017, 3.152, modified – The note to entry has been removed.]
3.1.28
fire severity
capacity of a fire to cause damage
[SOURCE: ISO 13943:2017, 3.155, modified – The note to entry has been removed.]

3.1.29
fire test
test that measures fire behaviour or exposes an item to the effects of a fire or reaction to fire
of the test specimen
Note 1 to entry: The results of a fire test can be used to quantify fire severity or determine the fire resistance or
reaction to fire of the test specimen.
[SOURCE: ISO 13943:2017, 3.157, modified – The words "or reaction to the fire of the test
specimen" have been added to the definition.]
3.1.30
fire stability
fire resistance ability of a building element to resist collapse for a stated period of time in a
standard fire resistance test
Note 1 to entry: The building element may or may not be load-bearing.
3.1.31
fire safety objective
desired outcome with respect to the probability of an unwanted fire, relative to essential aspects
of the built environment
Note 1 to entry: The essential aspects typically relate to the issues of life safety, conservation of property, continuity
of operations, protection of the environment and preservation of heritage.
[SOURCE: ISO 13943:2017, 3.151]
3.1.32
flame, noun
rapid, self-sustaining, sub-sonic propagation of combustion in a gaseous medium, usually with
the emission of light
[SOURCE: ISO 13943:2017, 3.159]
3.1.33
flame, verb
produce flame
[SOURCE: ISO 13943:2017, 3.160]
3.1.34
flame retarded
treated with a flame retardant
[SOURCE: ISO 13943:2017, 3.167, modified – The note to entry has been removed.]
3.1.35
flame application time
period of time for which a burner flame is applied to a test specimen
[SOURCE: ISO 13943:2017, 3.161]
3.1.36
flame retardant
substance which suppresses or delays the appearance of a flame and/or reduces the flame
spread rate
– 12 – IEC TR 62222:2021 © IEC 2021
3.1.37
flame retardance
property of a material whereby flaming combustion is slowed, terminated or prevented
Note 1 to entry: Flame retardance can be an inherent property of the basic material or it may be imparted by specific
treatment.
Note 2 to entry: The degree of the flame retardance exhibited by a material during testing can vary with the test
conditions.
3.1.38
flame spread
propagation of a flame front
[SOURCE: ISO 13943:2017, 3.168]
3.1.39
flame spread rate
DEPRECATED: burning rate
DEPRECATED: rate of burning
distance travelled by a flame front during its propagation, divided by the time of travel, under
specified conditions
[SOURCE: ISO 13943:2017, 3.169, modified – The note to entry has been removed.]
3.1.40
flaming
continuation of the presence of a flame after its first appearance
[SOURCE: ISO 13943:2017, 3.174]
3.1.41
flaming droplets
flaming molten or flaming liquefied drops which fall from the test specimen during the fire test
and continue to burn on the floor
[SOURCE: ISO 13943:2017, 3.177]
3.1.42
flammability
ability of a material or product to burn with a flame under specified conditions
[SOURCE: ISO 13943:2017, 3.178]
3.1.43
flammable
capable of flaming combustion under specified conditions
[SOURCE: ISO 13943:2017, 3.180]
3.1.44
flashover
transition state of total surface involvement in a fire of combustible materials
within an enclosure
[SOURCE: ISO 13943:2017, 3.184]

3.1.45
fuel
substance which can react exothermically with an oxidizing agent
[SOURCE: ISO 13943:2017, 3.189]
3.1.46
gross heat of combustion
heat of combustion of a substance when the combustion is complete and any produced water
is entirely condensed under specified conditions
[SOURCE: ISO 13943:2017, 3.198, modified – The notes to entry have been removed.]
3.1.47
halogen free
free from halogen according to IEC 60754-2
Note 1 to entry: When added to abbreviations, "halogen free, HF" can be added to mean that the material also
should be low smoke and have some resistance to ignitability, e.g. HF = halogen free, LS=low smoke, HFFR =
halogen free flame retardant, HFFR LS = halogen free, flame retardant and low smoke!
3.1.48
heat of combustion
DEPRECATED: calorific potential
DEPRECATED: calorific value
thermal energy produced by combustion of unit mass of a given substance
–1
Note 1 to entry: The typical unit is kilojoule per gram (kJ·g ).
[SOURCE: ISO 13943:2017, 3.203, modified – Note 1 to entry has been removed.]
3.1.49
heat release
thermal energy produced by combustion
[SOURCE: ISO 13943:2017, 3.205, modified – The note to entry has been removed.]
3.1.50
heat release rate
HRR
DEPRECATED: burning rate
DEPRECATED: rate of burning
rate of thermal energy production generated by combustion
[SOURCE: ISO 13943:2017, 3.206, modified – The abbreviated term "HRR" has been added,
and the note to entry has been removed.]
3.1.51
ignitability
measure of the ease with which a test specimen can be ignited, under specified conditions
[SOURCE: ISO 13943:2017, 3.212, modified – The synonym "ease of ignition" and the notes to
entry have been removed.]
– 14 – IEC TR 62222:2021 © IEC 2021
3.1.52
ignitable
capable of being ignited
[SOURCE: ISO 13943:2017, 3.213]
3.1.53
ignited
caused to be in a state of undergoing combustion
[SOURCE: ISO 13943:2017, 3.216]
3.1.54
irritant
gas or aerosol that stimulates nerve receptors in the lower respiratory tract, which
may result in breathing discomfort
Note 1 to entry: Examples of breathing discomfort are dyspnoea and an increase in respiratory rate. In severe
cases, pneumonitis or pulmonary oedema (which can be fatal) may occur some hours after exposure.
[SOURCE: ISO 13943:2017, 3.238]
3.1.55
opacity of smoke
ratio of incident light intensity to transmitted light intensity through smoke, under specified
conditions
Note 1 to entry: The opacity of smoke is the reciprocal of transmittance.
Note 2 to entry: The opacity of smoke is dimensionless.
[SOURCE: ISO 13943:2017, 3.287, modified – Note 1 to entry has been removed.]
3.1.56
optical density of smoke
measure of the attenuation of a light beam passing through smoke expressed as the logarithm
to the base 10 of the opacity of smoke
Note 1 to entry: The optical density of smoke is dimensionless.
[SOURCE: ISO 13943:2017, 3.288, modified – Note 1 to entry has been removed.]
3.1.57
oxidizing agent
substance capable of causing oxidation
[SOURCE: ISO 13943:2017, 3.290, modified – The note to entry has been deleted.]
3.1.58
reaction to fire
response of a product in contributing by its own decomposition to a fire to which it is exposed,
under specified conditions
3.1.59
reference fire scenario
fire scenario used as the basis of a fire test which is intended to reproduce specific aspects of
a fire in the built environment
[SOURCE: ISO 13943:2017, 3.327]

3.1.60
small fire attack
thermal attack produced by a small flame such as a match or lighter
3.1.61
smoke hazard
potential for injury and/or damage from smoke
3.1.62
smoke
visible part of fire effluent
[SOURCE: ISO 13943:2017, 3.347]
3.1.63
smoke production
amount of smoke which is produced in a fire or fire test
Note 1 to entry: Compare with the term "extinction area of smoke".
Note 2 to entry: The typical unit is m .
[SOURCE: ISO 13943:2017, 3.350]
3.1.64
smoke production rate
amount of smoke produced per unit time in a fire or fire test
Note 1 to entry: It is calculated as the product of the volumetric flow rate of smoke and the extinction coefficient of
the smoke at the point of measurement.
2 –1
Note 2 to entry: The typical unit is square metres per second (m s ).
[SOURCE: ISO 13943:2017, 3.351, modified – The notes to entry have been reformulated.]
3.1.65
toxic
poisonous
3.1.66
toxicant
toxin
toxic substance
[SOURCE: ISO 13943:2017, 3.404]

– 16 – IEC TR 62222:2021 © IEC 2021
3.2 Abbreviated terms
CENELEC European Committee for Electrotechnical Standardization
CPR Construction Products Regulation
CSA Canadian Standards Association
EN European norm (coming from CENELEC)
FEP fluorinated ethylene propylene
FIPEC
fire performance of electric cables [4]
HR heat release
HRR heat release rate
ISO International Organization for Standardization
NFPA National Fire Protection Association
OD optical density
PE polyethylene
PP polypropylene
PTFE polytetrafluoroethylene
PVC polyvinyl chloride
PVDF polyvinylidene fluoride
SP smoke production
SPR smoke production rate
THR total heat release
TSP total smoke production
UL Underwriters Laboratories Inc.

4 Communications cabling in buildings
4.1 Installations and associated fire danger
Large buildings are being designed and constructed using similar architectural techniques
resulting in the distribution of utilities using risers between floors, raised floors and suspended
ceilings – all of which act as building voids through which fire and smoke can spread.
These building voids accommodate cables to serve a variety of purposes. In new offices, it is
common for more than 80 % of cables (by length) to be communication cables which increase
the fuel load (flammability) of the building in the event of a fire – an aspect addressed by local
regulations and standards such as ISO/IEC 14763-2 (and EN 50174-2 in Europe).
As transmission rates have increased from kilobits/s to many Gigabits/s, system upgrades to
higher performance cables and components have been necessary leading to the multiple
phases of installation of communications cables, mainly in hidden voids.
The majority of the communications cables support the structured cabling systems specified by
ISO/IEC 11801 (all parts), EN 50173 (all parts) and ANSI/TIA-568 (all parts), termed generic
information technology cabling systems, which serve data centres (computer rooms) and
information technology service distribution throughout office, industrial and residential premises.
__________
Numbers in square brackets refer to the Bibliography.

More recently, standards for remote powering over generic information technology cabling have
resulted in a further increase in installations to support distributed building services in all types
of premises.
Whilst cables may be installed in conformance with a required transmission performance, they
are unlikely to perform in the same manner under fire conditions. The reaction to fire tests do
not normally assess transmission performance. The pass/fail criteria for resistance to fire tests
are typically a simple degradation in cable transmission performance, which might not ensure
that the system itself continues to perform at the required level.
The generic structured cabling system is a hierarchical star network linking distributors to other
distributors and to outlets distributed throughout the premises. Cables are routed in risers
between floors and in ceiling and underfloor voids. Even in a small office, this leads to a large
number of cables being run in building voids.
Generic cabling systems use copper conductor cables manufactured to IEC 61156 (all parts)
(EN 50288 series in Europe) and optical cables manufactured to IEC 60794-2 (all parts). These
standards detail electrical and optical transmission requirements, mechanical performance and
environmental characteristics. Communication cables operating at low voltages and currents
are not a primary cause of fires, but their widespread use means that they may be involved in
outbreaks of fire from an external source.
In order to define the appropriate fire test methods and performance requirements, it is
necessary to consider the fire hazards presented by typical cable installations.
IEC 60695-1-10 gives general guidance on the fire hazards of electrotechnical products.
A review of typical installations of communication cables in buildings, summarised in Annex A,
suggests the following general trends.
a) In public buildings such as airports, shops and older commercial offices with solid floors,
cables are generally installed in ceiling voids with some local cabling in wall ducts.
Standards specify segregation of communication and power cables in relation to
electromagnetic interference and local regulations generally require segregation for
electrical safety.
b) Generally, in offices and newer commercial offices, cables are installed in ceiling/underfloor
voids and wall ducts. Lighting power cables and some communication cables are run in
ceiling voids, whilst computer and telephone cables and their associated low voltage power
cables are often run in underfloor voids. Again, standards specify segregation of
communication and power cables in relation to electromagnetic interference and local
regulations generally require segregation for electrical safety. In such installations, relatively
shallow raised flooring provides the underfloor voids.
c) In newer large commercial offices with extensive computer facilities, the raised flooring is
deep (1,0 m to 1,5 m is not uncommon) and can both accommodate cables and provide
environmental air to information technology and other equipment.
d) Underfloor and ceiling voids can have particular airflow dynamics, especially where proper
compartmentation was not considered, which could be reflected in the test method. In
general, as airflow rate increases or another sufficient fire source energy in any given
apparatus raises, the risk of fire propagation increases.
e) A considerable quantity of cables can be installed in vertical riser shafts where a chimney
effect could result in the event of a fire. For convenience, these may be the same cables as
are used for horizontal runs.
f) Patch cords and work area cables, whilst not permanently installed in buildings, often
accumulate in large numbers and have been included in the scope of this document.
g) In many installations, cables can run behind and within walls.

– 18 – IEC TR 62222:2021 © IEC 2021
4.2 Mitigation of fire hazards
4.2.1 Balanced approach
A balanced approach to fire mitigation should be used wherever possible. Assessing in isolation,
i.e. using room by room designs, using test methods or fire hazards or mitigation shall be
avoided.
4.2.2 Fire hazard management
Before considering the fire hazard and the fire safety objective, compartmentation should
already have been considered. In cases where the location and contents of specific
compartments remove the need to consider fire hazards as described in Table 1, the
maintenance of the boundaries of those compartments is critical to the fire performance on the
premises as a whole.
Table 1 – Traditional ranking of fire hazards
Ranking Installations where General installations Installations where
evacuation of personnel protection of equipment is
is critical critical
0 (most important) Ignitability Ignitability Ignitability
1 Smoke heat release/flame spread Corrosive fire effluent
2 Heat release/flame spread Smoke Heat release/flame spread
3 Toxic fire effluent Corrosive fire effluent Smoke
4 (least important) Corrosive fire effluent Toxic fire effluent Toxic fire effluent

The fire hazard of each compartment should be assessed in accordance with Table 1, which
gives an indication of the degree of mitigation that is necessary in a variety of installations.
Other factors should be considered as part of the risk assessment and business continuity
analysis. The assessment should consider:
a) architectural considerations;
b) the fabric and contents of the compartment building;
c) the requirements of the owners, landlords, tenants and insurers, including for example
1) protection of the building and its personnel;
2) business continuity;
3) aesthetics and finish;
4) electrical and optical performance of the cabling system;
d) the nature of the fire hazard;
e) the extent of the fire load within the local area where the cable is being installed including,
for example:
1) debris fire (small fire attack) waste paper/plastics collection areas, bins or boxes;
2) furniture, density of the office, open plan;
3) arson, ground floor, access or side streets;
f) chimney effects;
g) forced air environments.
In such cases, the use of cables with enhanced fire performance should be considered.

4.2.3 Compartmentation
When economies of scale, speed of installation and overall practicality have to be considered,
a most economical solution could be chosen using a cable of lower fire performance consistent
with the need to evacuate personnel (see Table 1), in which case it is necessary to:
a) apply increased levels of fire protection in certain compartments served by that cable, such
as the use of water sprinklers or the use of non-combustible conduit; or
b) create additional sub-compartments in order to increase the level of fire protection; and/or
c) raise the level of fire performance of the cables.
5 Fire hazard
5.1 Fire hazard considerations
The traditional approach to the fire performance of cables was based on the hazards presented
by the cable designs, cable-making materials and installations applicable at that time. Since
then, new cable designs, materials and installation practices have been deployed, particularly
for communication and computer cables.
Ease of ignition cannot be ignored but, with all fires, a material that is easiest to ignite (ignitable)
will always be the first to develop flames; from this point on, fire engineering takes over.
Developments have taken place with regard to cable design, materials and installation practices,
particularly associated with communications cabling. Recent and current research has
introduced considerations of fire science and fire engineering, and discussions with fire
professionals have shown their major concerns to be flame spread, heat (linked to flashover
and structural collapse), smoke and toxic effluent (affecting building evacuation and fire-fighter
safety).
The following guidance is now available:
• ISO 13571: Life-threatening components of fire; guidelines for the estimation of time to
compromised tenability in fires;
• IEC 60695-1-10: Guidance for assessing the fire hazard of electrotechnical products;
general requirements;
• IEC 60695-1-11: Guidance for assessing the fire hazard of electrotechnical products; fire
hazard assessment.
Investigations of fires have shown that communication cables are not a primary source of fire.
However, communication cables may be involved in, and contribute to the spread of, fires from
other sources. Such sources include faults in power equipment, lighting equipment and more
general fires caused by combustible waste.
NOTE Examples of fire spread routes are identified by ISO TC 92. Fire spread within roofs, above ceilings, below
floors and through horizontal and vertical building voids are considered relevant to communication cables in buildings.
For example, ISO 19706 discusses generation and nature of effluent.
Many more fires have occurred which have shown that communication cables are still not a
primary source of fire, but they may be involved in fires caused, for example, by
• electrical faults in power equipment leading to riser cable fires;
• lighting fittings faults causing fires in concealed ceiling voids;
• rubbish fires and faults in cabinet fans resulting in computer room cabling fires.

The results of research indicate that, when considering suitable test methods to assess cable
reaction to fire characteristics, the following should be taken into account.

– 20 – IEC TR 62222:2021 © IEC 2021
a) Flame spread
Some test methods measure flame spread rate during the test, and others measure char
length (damaged length) after the test. Some sheathing materials are designed to char in
order to restrict flame propagation (flame retardance), in which case the char length after
the test can be greater than the flame spread during the test. It is now recognised that the
measurement of char at the completion of the test is not a measure of flame spread, and
research such as the FIPEC project (see Annex E) suggests that heat release rate is a
better measure of fire growth.
Attention is drawn to the guidance on surface spread of flame given in IEC 60695-9-1 and
to the summary and relevance of test methods given in IEC 60695-9-2.
b) Heat
Heat is a fire hazard not currently addressed by IEC cable standards, but is addressed by
EN 50399 (see 5.2). Generally, cables would be involved in a developing fire (cont
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