SIST EN ISO 13506-2:2024

SLOVENSKI STANDARD
01-november-2024
Varovalna obleka pred učinki toplote in ognja - 2. del: Predvidevanje nastanka
poškodb kože zaradi opeklin - Zahteve za izračun in primeri preskusov (ISO 13506-
2:2024)
Protective clothing against heat and flame - Part 2: Skin burn injury prediction -
Calculation requirements and test cases (ISO 13506-2:2024)
Schutzkleidung gegen Hitze und Flammen - Teil 2: Vorhersage von
Verbrennungsverletzungen der Haut - Berechnungsanforderungen und Prüffälle (ISO
13506-2:2024)
Habillement de protection contre la chaleur et les flammes - Partie 2: Prédiction de
blessure par brûlure de la peau - Exigences de calculs et cas d'essai (ISO 13506-
2:2024)
Ta slovenski standard je istoveten z: EN ISO 13506-2:2024
ICS:
13.340.10 Varovalna obleka Protective clothing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 13506-2
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2024
EUROPÄISCHE NORM
ICS 13.340.10
English Version
Protective clothing against heat and flame - Part 2: Skin
burn injury prediction - Calculation requirements and test
cases (ISO 13506-2:2024)
Habillement de protection contre la chaleur et les Schutzkleidung gegen Hitze und Flammen - Teil 2:
flammes - Partie 2: Prédiction de blessure par brûlure Vorhersage von Verbrennungsverletzungen der Haut -
de la peau - Exigences de calculs et cas d'essai (ISO Berechnungsanforderungen und Prüffälle (ISO 13506-
13506-2:2024) 2:2024)
This European Standard was approved by CEN on 21 June 2024.

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-CENELEC 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-CENELEC Management
Centre has the same status as the official versions.

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Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13506-2:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 13506-2:2024) has been prepared by Technical Committee ISO/TC 94
"Personal safety -- Personal protective equipment" in collaboration with Technical Committee CEN/TC
162 “Protective clothing including hand and arm protection and lifejackets” the secretariat of which is
held by DIN.
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 December 2024, and conflicting national standards
shall be withdrawn at the latest by December 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 13506-2:2024 has been approved by CEN as EN ISO 13506-2:2024 without any
modification.
International
Standard
ISO 13506-2
Second edition
Protective clothing against heat
2024-06
and flame —
Part 2:
Skin burn injury prediction —
Calculation requirements and
test cases
Habillement de protection contre la chaleur et les flammes —
Partie 2: Prédiction de blessure par brûlure de la peau —
Exigences de calculs et cas d'essai
Reference number
ISO 13506-2:2024(en) © ISO 2024

ISO 13506-2:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 13506-2:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 3
5 Apparatus, specimen preparation and test procedure . 3
6 Predicted skin burn injury calculation . 4
6.1 Skin model .4
6.1.1 General .4
6.1.2 Manikin sensor heat flux values as function of time .4
6.1.3 Determination of the predicted skin and subcutaneous tissue (adipose) internal
temperature field .4
6.1.4 Initial and boundary conditions .6
6.1.5 Determination of the Ω value for the prediction of skin burn injury .7
6.1.6 Time to pain .7
7 Skin burn injury calculation test cases and in situ calibration . 8
7.1 Test cases and in situ validation .8
7.2 Skin layer temperature prediction test cases .8
7.2.1 General .8
7.2.2 Case one .8
7.2.3 Case two .8
7.2.4 Accuracy requirement .9
7.3 Skin burn injury calculation test cases.9
7.4 In situ validation of burn injury prediction .10
8 Test report .11
8.1 General .11
8.2 Skin model .11
8.3 Calculated results .11
8.3.1 General .11
8.3.2 Predicted area (%) of manikin injured based on the total area of the manikin
containing heat flux sensors . 12
8.3.3 Predicted area (%) of manikin injured based only on the area of manikin
covered by the test specimen . 12
8.3.4 Other information . 12
Annex A (normative) Skin model with temperature-dependent thermal conductivity, k(x,T) .13
Annex B (informative) Interlaboratory test data analysis .16
Bibliography .18

iii
ISO 13506-2:2024(en)
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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 94, Personal safety — Personal protective
equipment, Subcommittee SC 13, Protective clothing, in collaboration with the European Committee for
Standardization (CEN) Technical Committee CEN/TC 162, Protective clothing including hand and arm
protection and lifejackets, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This second edition of ISO 13506-2, cancels and replaces the first edition (ISO 13506-2:2017), which has
been technically revised.
A list of all parts in the ISO 13506 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 13506-2:2024(en)
Introduction
The purpose of heat and flame-resistant protective clothing is to shield the wearer from hazards that can
cause skin burn injury. The clothing can be made from one or more materials, which can be made into a
garment or protective clothing ensemble for testing on a manikin fire exposure system.
This document is a companion document to ISO 13506-1. The data gathered by tests according to ISO 13506-1
are used as input for this calculation.
In ISO 13506-1, a stationary, upright, adult-sized manikin (male or female) is dressed in a garment or
protective clothing ensemble and exposed to a laboratory simulation of a fire with controlled heat flux,
duration and flame distribution. The average incident heat flux to the exterior of the garment is 84 kW/
m . Thermal energy sensors are fitted to the surface of the manikin. The output from the sensors is used
to calculate the heat flux variation with time and location on the manikin and to determine the total
energy absorbed over the data-gathering period. The data-gathering period is selected to ensure that the
total energy transferred will no longer be rising. The information obtained from the calculation of skin
burn injury prediction (see Annex B) can be used to assist in evaluating the performance of the garment or
protective clothing ensemble under the test conditions. It can also be used as a model-based tool to estimate
the extent and nature of potential skin damage resulting from the exposure of the test garment.
Fit of the garment or protective clothing ensemble on the manikin is important. Thus, variations in garment
or protective clothing ensemble design and how the manikin is dressed by the operator may influence the
test results and skin burn injury prediction. Experience suggests that testing a garment one size larger than
the standard can reduce the percentage of predicted body burn by up to 5 %.
ISO 13506-1 uses the calculated skin injury information in the calculation of the thermal manikin
performance factor.
The method described in this document as an optional part in the fire fighter standards ISO 11999-3 and
EN 469 and as an optional part in the industrial heat and flame protective clothing standard ISO 11612.
[5] [6]
The National Fire Protection Association standard NFPA 2112 specifies ASTM F1930-18 , which is a
test method similar to the one described in ISO 13506-1 and which contains skin burn injury prediction
calculations similar to the one described in this document.

v
International Standard ISO 13506-2:2024(en)
Protective clothing against heat and flame —
Part 2:
Skin burn injury prediction — Calculation requirements and
test cases
1 Scope
This document provides technical details for calculating predicted burn injury to human skin when its
surface is subject to a varying heat flux, such as may occur due to energy transmitted through and by a
garment or protective clothing ensemble exposed to flames. A series of test cases are provided against
which the burn injury prediction calculation method is verified. It also contains requirements for the in situ
calibration of the thermal energy sensor — skin injury prediction system for the range of heat fluxes that
occur under garments.
The skin burn injury calculation methods as presented in this test method do not include terms for handling
short wavelength radiation that may penetrate the skin. The latter include arc flashes, some types of fire
exposures with liquid or solid fuels, and nuclear sources.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 11610, Protective clothing — Vocabulary
ISO 13506-1, Protective clothing against heat and flame — Part 1: Test method for complete garments —
Measurement of transferred energy using an instrumented manikin
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13506-1 and ISO 11610 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

ISO 13506-2:2024(en)
3.1
burn injury
damage which occurs at various depths within human tissue due to elevated temperatures resulting from
heat transfer to the surface
Note 1 to entry: Burn injury in human tissue occurs when the tissue is heated and kept at an elevated temperature
(>44 °C) for a critical period of time. In this document, it is assumed that skin has three layers: the epidermis, which
is the tough outer layer, the dermis, which is the layer below the epidermis, and the subcutaneous tissue (adipose),
which is the fatty layer of tissue deeper than the dermis. In this document, it is assumed that the thicknesses of the
layers are the same everywhere on the human body. Variations in thickness that occur with age, location and sex are
not included. The severity of damage, referred to as predicted first-, second-, or third-degree (or partial thickness or
full thickness) burn injury, depends upon the magnitude of the elevated temperature above 44 °C and the time during
which it remains at or above 44 °C.
3.1.1
first-degree burn injury
first-degree burn
burn damage in which only the superficial part of the epidermis has been injured
Note 1 to entry: The skin turns red, but does not blister or actually burn through. First-degree burn injury is reversible.
In this document, the time for a predicted first-degree burn injury to occur is indicated when the value of Ω = 0,53 [see
Formula (3)] at a skin depth of 75 μm, i.e. at the epidermis/dermis interface.
3.1.1.1
first-degree burn injury area
first-degree burn area
sum of the areas represented by heat flux sensors for which only a calculated first-degree burn injury (3.1.1)
is predicted to occur
3.1.2
second-degree burn injury
second-degree burn
partial thickness burn
burn damage in which the epidermis and a varying extent of the dermis are burned, but the entire thickness
of the dermis is not usually destroyed and the subcutaneous layer is not injured
Note 1 to entry: Second-degree burn injury is more serious than first-degree burn injury, resulting in complete
necrosis (living cell death) of the epidermis layer, usually accompanied with a blister, but is reversible especially if the
affected area is small. In this document, the time for a predicted second-degree burn injury to occur is indicated when
the value of Ω = 1,0 [see Formula (3)] at a skin depth of 75 μm, i.e. at the epidermis/dermis interface.
3.1.2.1
second-degree burn injury area
second-degree burn area
sum of the areas represented by heat flux sensors for which a calculated second-degree burn injury is the
most severe injury predicted to occur
3.1.3
third-degree burn injury
third-degree burn
full thickness burn
burn damage which extends through the dermis, into or beyond the subcutaneous tissue
Note 1 to entry: Third-degree burn injury is not reversible. In this document, the time for a predicted third-degree
burn injury to occur is indicated when the value of Ω = 1,0 [see Formula (3)] at a skin depth of 1 200 μm, i.e. at the
dermis/subcutaneous interface.
3.1.3.1
third-degree burn injury area
third-degree burn area
sum of the areas represented by the heat flux sensors for which a calculated third-degree burn injury (3.1.3)
is predicted to occur
ISO 13506-2:2024(en)
3.1.4
total burn injury area
total burn area
sum of the areas represented by the heat flux sensors for which at least a second-degree burn injury is
predicted to occur
3.2
omega value
Ω
skin injury parameter, the value of the damage integral [see Formula (3)], which indicates predicted burn
injury (3.1) at specific skin depths and temperature regimes
3.3
time to pain
time taken for the pain receptors to reach 43,2 °C
Note 1 to entry: In this document, the pain receptors are located 195 μm below the surface of the skin.
4 General
The calculation of predicted skin burn injury is a desirable result when used to compare the relative
performance of protective clothing using test methods that measure heat to the manikin surface for a
defined thermal energy exposure. This document outlines the calculation method that shall be used for
this purpose when conducting the tests as described in ISO 13506-1. ISO 13506-1 specifies the method
for the measurement of the energy transfer, which can be used as a basis for evaluation of the relative
thermal protective performance of the test specimen. The performance is a function of both the materials
of construction and design and of fit of clothing onto the test manikin. The average exposure heat flux is
84 kW/m with durations from 3 s to 20 s.
Predicted burn injury determined in this test method uses a simplified mathematical model that does not
directly translate into actual human skin burn injury for any exposure test conditions. The model is based
[8]
on measurements on human volar forearms (Stoll and Greene ).
The test specimen is placed on an adult-size manikin (see ISO 13506-1:2024, 5.1) at ambient atmospheric
conditions and exposed to a laboratory simulation of a fire with controlled heat flux, duration and flame
distribution. The test procedure, data acquisition, result calculations and preparation of the test report are
performed with computer hardware and software programs.
Thermal energy transferred through the test specimen and from the test specimen to the surface of the
manikin during and after the exposure is measured by heat flux sensors positioned in the surface of the
manikin. The amount of heat varies with time. The method specified in this document uses the heat flux
measurements of ISO 13506-1 to calculate the predicted time to pain for each thermal energy sensor, the
first, second- and third-degree burn injury areas, and the total burn injury area resulting from the exposure.
Identification of the test specimen, test conditions, comments and remarks about the test purpose and
response of the test specimen to the exposure are recorded and are included as part of the test report. The
total energy transferred and/or the predicted skin burn injury area, and the way the test specimen responds
to the flame exposure are indicators for the performance of the test specimen for this test method. The skin
burn injury prediction method can be used with other test methods that produce similar exposures.
Clause 6 gives the details of the required calculation of predicted skin injury, while Clause 7 lists a series
of test cases against which the calculation method shall be tested to demonstrate compliance with the
specified accuracy.
5 Apparatus, specimen preparation and test procedure
The apparatus details, test specimen preparation and dressing and the test procedure are given in
ISO 13506-1:2024, Clauses 5 to 8. In addition to the calibration procedures given in ISO 13506-1:2024,
Annex C, laboratories shall carry out the validation described in Clause 7.

ISO 13506-2:2024(en)
6 Predicted skin burn injury calculation
6.1 Skin model
6.1.1 General
This document contains the specifications for two skin models.
— The skin property values for the skin model with temperature-dependent thermal conductivity (Skin
Model A) shall be as specified in the Table 1, Table 2 and Annex A.
— The skin property values for the skin model with temperature-independent thermal conductivity (Skin
Model B) shall be as specified in Table 1 and Table 3.
NOTE 1 The skin property values listed in Table 1 to Table 3 and Annex A and the calculation test cases specified
in Clause 7 were determined by a task group within ASTM (American Society for Testing and Materials) working on
[6]
ASTM F1930 , a test method developed jointly with the ISO 13506 series. The task group reverse engineered the Stoll
[7]
and Greene experiments so as to match within 10 % the Ω = 1,0 [Formula (3)] condition for all the Stoll partial blister
test cases. The values for the thicknesses of the three layers (in vivo) in the forearms of adult males were found in the
literature, as was the initial temperature gradient through the layers in the forearm (1 °C). Using this information, the
[8]
formulae given in 6.1.3 and 6.1.5 and the values of P and ΔE determined by Weaver and Stoll shown below, trial and
error and optimization techniques were used to find the values of thermal conductivity, specific heat and density of
[7]
the individual layers so that, with one set of values, all the Stoll and Greene experimental skin injury measurements
[8]
plus extensions calculated by Weaver and Stoll could be predicted with Ω = 1 ± 0,1. The values determined are
representative of the living tissue (in vivo). As such, blood flow and its potential effect on the results/predictions are
implicit in the solution using the formulae and parameters given in below.
NOTE 2 ASTM F1930 contains detailed historical information on the development of skin injury prediction due to
thermal influx from hot fluids and pure radiant sources.
6.1.2 Manikin sensor heat flux values as function of time
-2
The absorbed heat flux values, qt , in kW m for each manikin sensor, i, at each time step, t, as provided
()
i
by ISO 13506-1 shall be taken as data input for the calculation of skin burn injury prediction.
6.1.3 Determination of the predicted skin and subcutaneous tissue (adipose) internal
temperature field
6.1.3.1 General
The thermal exposure shall be represented as a transient one-dimensional heat diffusion problem in which
the temperature within the epidermis and dermis layers of skin and subcutaneous tissue (adipose) varies
with both position (depth) and time, and is described by the parabolic differential Formula (1) (Fourier’s
field equation):
∂T ∂ T
ρC =k (1)
p
∂t
∂x
where
-3 -1
ρC is the volumetric heat capacity, in J·m ·K ;
p
t is the time, in s;
x is the depth from skin surface, in m;
T(x,t)
...