SIST EN ISO 13732-1:2007

Ergonomics of the thermal environment - Methods for the assessment of human responses to contact with surfaces - Part 1: Hot surfaces (ISO 13732-1:2006)

This standard provides temperature threshold values for the occurrence of burns when the human skin is in contact with a hot solid surface.
This standard also describes methods for the assessment of the risks of burning, when humans can or may touch hot surfaces with the unprotected skin.
This standard also gives guidance when it is necessary to specify temperature limit values for hot surfaces. This standard gives guidance but does not set surface temperature limit values.
NOTE 1   Such temperature limit values may be specified in specific product standards or in regulations in order to prevent human beings to sustain burns when in contact with the hot surface of  a product.
This standard applies to contact periods of 0,5 s and longer.
This standard is not applicable if a large area of the skin (approximately 10 % or more of the skin of the whole body) can be in contact with the hot surface. This standard is also not applicable to skin contact of more than 10 % of the head or contact which could result in burns of vital areas of the face.
NOTE 2   In some cases the results of contact with a hot surface may be more serious for the individual, e.g.:
· burns resulting in the restriction of airways;
· large burn (more than 10 % of the body surface) may impair the circulation by fluid loss;
· heating of a large proportion of the head or whole body may lead to unacceptable heat strain even in the absence of burning.
This standard applies to hot surfaces of all kind of objects: equipment, products, buildings, natural objects, etc. In order to simplify the standard only products are mentioned herein, but it applies to all other objects, too.
This standard applies to products used in any environment, e.g. workplaces, the home etc..
This standard applies to hot surfaces of products which may be touched by healthy adults, children, elderly people and also by people with physical disabilities.

Ergonomie der thermischen Umgebung - Bewertungsverfahren für menschliche Reaktionen bei Kontakt mit Oberflächen - Teil 1: Heiße Oberflächen (ISO 13732-1:2006)

Dieser Teil von ISO 13732 stellt Temperaturschwellenwerte für Verbrennungen zur Verfügung, die auftreten, wenn es zum Kontakt der menschlichen Haut mit einer heißen, festen Oberfläche kommt.
Sie beschreibt außerdem Verfahren zur Bewertung von Verbrennungsrisiken in Situationen, in denen Menschen heiße Oberflächen mit ihrer ungeschützten Haut berühren können oder dürfen.
Dieser Teil von ISO 13732 gibt auch Leitlinien für Fälle, in denen es erforderlich ist, Temperaturschwel¬lenwerte für heiße Oberflächen festzulegen. Sie legt jedoch keine Grenzwerte für Oberflächentemperaturen fest.
ANMERKUNG 1   Um zu verhindern, dass Menschen bei Berühren der heißen Oberfläche eines Produktes Verbrennungen davontragen, können derartige Temperaturgrenzwerte in besonderen Produktnormen oder in Vorschriften festgelegt werden.
Dieser Teil von ISO 13732 gilt für eine Kontaktdauer von 0,5 s und länger.
Sie ist anwendbar für Kontakte bei denen die Oberflächentemperatur während des Kontaktes in Wesentlichen unverändert bleibt (siehe 4.1).
Sie ist nicht anwendbar, wenn ein großer Bereich der Haut (etwa 10 % oder mehr der Körperoberfläche) mit einer heißen Oberfläche in Berührung kommen kann. Sie ist ebenfalls nicht anwendbar bei einem Hautkontakt von mehr als 10 % des Kopfes oder einem Kontakt, der Verbrennungen von lebenswichtigen Bereichen des Gesichtes zur Folge hat.
ANMERKUNG 2   In einigen Fällen kann der Kontakt mit einer heißen Oberfläche für eine Person noch schwerwie¬gender sein, z. B.:
-   Verbrennungen, die zu einer Verengung der Atemwege führen;
-   großflächige Verbrennungen (von mehr als 10 % der Körperoberfläche) können den Blutkreislauf durch Flüssigkeits¬verlust beeinträchtigen;
-   die Erhitzung eines großen Teils des Kopfes oder des gesamten Körpers kann selbst ohne das Auftreten einer Verbrennung zu einer nicht akzeptablen Hitzebeanspruchung führen.

Ergonomie des ambiances thermiques - Méthodes d'évaluation de la réponse humaine au contact avec des surfaces - Partie 1: Surfaces chaudes (ISO 13732-1:2006)

La présente norme indique des valeurs seuil de température auxquelles des brulures interviennent lorsque la peau de l'etre humain entre en contact avec une surface solide chaude.
Elle décrit également des méthodes permettant d'évaluer les risques de brulure lorsque des personnes peuvent ou sont susceptibles de toucher des surface chaudes sans que leur peau ne soit protégée.
La norme, qui donne également des indications lorsqu'il est nécessaire de spécifier des valeurs limites de températures pour des surfaces chaudes, n'établit nullement de valeurs limites de températures des surfaces.
NOTE 1   Ces valeurs limites de température peuvent etre spécifiées dans des normes de produits ou dans des reglements afin d'éviter que des personnes ne subissent de brulures si elles touchent la surface chaude d'un produit.
La présente norme concerne des durées de contact de 0,5 s et plus.
La présente norme n'est pas applicable si une surface importante de peau (environ 10 % ou plus de la peau de l'ensemble du corps) peut etre en contact avec la surface chaude. Elle ne s'applique pas non plus dans les cas de contact avec plus de 10 % de la tete ou de contacts susceptibles d'engendrer des brulures des zones vitales du visage.
NOTE 2   Dans certains cas, le contact avec la surface chaude peut avoir des conséquences plus graves pour l'individu, il peut, par exemple provoquer :
-   des brulures engendrant une limitation de la capacité des voies respiratoires ;
-   une brulure étendue (recouvrant plus de 10 % de la surface du corps) susceptible d'entraver la circulation par perte de liquides ;
-   un échauffement d'une grande proportion de la tete ou de la totalité du corps, pouvant engendrer une contrainte thermique inacceptable, meme en l'absence de brulures.
La présente norme s'applique aux surfaces chaudes de toutes sortes d'objets : équipements, produits, bâtiments, objets naturels, etc.. Par souci de simplification la norme ne concerne que des produits, mais elle est également appl

Ergonomija toplotnega okolja – Metode za oceno človekovega odziva na dotik s površinami – 1. del: Vroče površine (ISO 13732-1:2006)

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-2006
• Withdrawal Date: 23-Oct-2008
• ICS: 13.180 - Ergonomics
• Technical Committee: VSN - Safety of machinery
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 22-Oct-2008
• Due Date: 14-Nov-2008
• Completion Date: 24-Oct-2008
• Directive: 98/37/EC - Machinery
• Mandate: M/079 - Mandate to CEN and CENELEC for standardization in the field of machines
• Ref Project: EN ISO 13732-1:2006 - Ergonomics of the thermal environment - Methods for the assessment of human responses to contact with surfaces - Part 1: Hot surfaces (ISO 13732-1:2006)

Relations

• Replaces: SIST EN 563:1998/A1:2000 - Safety of machinery - Temperatures of touchable surfaces - Ergonomics data to establish temperature limit values for hot surfaces
• Effective Date: 01-May-2010
• Replaces: SIST EN 563:1998 - Safety of machinery - Temperatures of touchable surfaces - Ergonomics data to establish temperature limit values for hot surfaces
• Effective Date: 01-May-2010
• Replaces: SIST EN 563:1998/AC:1998 - Safety of machinery - Temperatures of touchable surfaces - Ergonomics data to establish temperature limit values for hot surfaces - Amendment
• Effective Date: 01-May-2010
• Replaced By: SIST EN ISO 13732-1:2008 - Ergonomics of the thermal environment - Methods for the assessment of human responses to contact with surfaces - Part 1: Hot surfaces (ISO 13732-1:2006)
• Effective Date: 01-Dec-2008
• Replaces: SIST EN 563:1998/A1:2000/AC:2002 - Safety of machinery - Temperatures of touchable surfaces - Ergonomics data to establish temperature limit values for hot surfaces
• Effective Date: 01-May-2010

Standards Content (Sample)

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EUROPEAN STANDARD
EN ISO 13732-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2006
ICS 13.180 Supersedes EN 13202:2000, EN 563:1994
English Version
Ergonomics of the thermal environment - Methods for the
assessment of human responses to contact with surfaces - Part
1: Hot surfaces (ISO 13732-1:2006)
Ergonomie des ambiances thermiques - Méthodes Ergonomie der thermischen Umgebung -
d'évaluation de la réponse humaine au contact avec des Bewertungsverfahren für menschliche Reaktionen bei
surfaces - Partie 1: Surfaces chaudes (ISO 13732-1:2006) Kontakt mit Oberflächen - Teil 1: Heiße Oberflächen (ISO
13732-1:2006)
This European Standard was approved by CEN on 19 August 2006.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, 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: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13732-1:2006: E
worldwide for CEN national Members.

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EN ISO 13732-1:2006 (E)





Foreword


This document (EN ISO 13732-1:2006) has been prepared by Technical Committee CEN/TC 122
"Ergonomics", the secretariat of which is held by DIN, in collaboration with Technical Committee
ISO/TC 159 "Ergonomics".

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 2007, and conflicting national standards
shall be withdrawn at the latest by March 2007.

This document supersedes EN 13202:2000 and EN 563:1994.

This document has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, 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.

2

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EN ISO 13732-1:2006 (E)



Annex ZA
(informative)

Relationship between this European Standard and the Essential
Requirements of EU Directive 98/37/EC, amended by Directive
98/79/EC


This European Standard has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association to provide a means of conforming to
Essential Requirements of the New Approach Directive 98/37/EC, amended by Directive 98/79/EC.

Once this standard is cited in the Official Journal of the European Communities under that Directive
and has been implemented as a national standard in at least one Member State, compliance with
the normative clauses of this standard given in Table ZA.1 confers, within the limits of the scope of
this standard, a presumption of conformity with the corresponding Essential Requirements of that
Directive and associated EFTA regulations.

Table ZA.1 — Correspondence between this European Standard and Directive 98/37/EC

Clauses/sub-clauses of this Essential requirements (ERs) Qualifying remarks/Notes
European Standard of EU Directive 98/37/EC

3, 4, 5.2 to 5.7, and Annex B 1.5.5

WARNING: Other requirements and other EU Directives may be applicable to the products falling
within the scope of this standard.

3

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INTERNATIONAL ISO
STANDARD 13732-1
First edition
2006-09-01

Ergonomics of the thermal
environment — Methods for the
assessment of human responses to
contact with surfaces —
Part 1:
Hot surfaces
Ergonomie des ambiances thermiques — Méthodes d'évaluation de la
réponse humaine au contact avec des surfaces —
Partie 1: Surfaces chaudes




Reference number
ISO 13732-1:2006(E)
©
ISO 2006

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ISO 13732-1:2006(E)
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ii © ISO 2006 – All rights reserved

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ISO 13732-1:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions. 2
4 Burn thresholds . 3
4.1 General. 3
4.2 Burn threshold data. 4
5 Assessment of risk of burning . 10
5.1 Procedure . 10
5.2 Identification of hot, touchable surfaces. 10
5.3 Task analysis. 11
5.4 Measurements of surface temperatures. 11
5.5 Choice of applicable burn threshold value . 12
5.6 Comparison of surface temperature and burn threshold. 13
5.7 Determination of risk of burning . 14
5.8 Repetition . 14
6 Protective measures. 15
6.1 General. 15
6.2 No risk of burning. 15
6.3 Risk of burning. 15
7 Guidance for setting surface temperature limit values . 16
7.1 Procedure . 16
7.2 Assessment of risk of burning . 16
7.3 Decision upon protective measures. 16
7.4 Selection of appropriate values . 16
7.5 Setting of surface temperature limit value. 17
Annex A (informative) Scientific background . 18
Annex B (normative) Contact periods. 20
Annex C (informative) Flow charts for application of this part of ISO 13732. 21
Annex D (informative) Thermal properties of selected materials. 23
Annex E (informative) Examples of protective measures against burns . 24
Annex F (informative) Example for assessment of risk of burning . 26
Annex G (informative) Examples for setting surface temperature limit values. 31
Annex H (informative) Safety signs for hot surfaces. 35
Bibliography . 37

© ISO 2006 – All rights reserved iii

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ISO 13732-1:2006(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 13732-1 was prepared by the European Committee for Standardization (CEN) Technical Committee
CEN/TC 122, Ergonomics, in collaboration with Technical Committee ISO/TC 159, Ergonomics,
Subcommittee SC 5, Ergonomics of the physical environment, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
ISO 13732 consists of the following parts, under the general title Ergonomics of the thermal environment —
Methods for the assessment of human responses to contact with surfaces:
⎯ Part 1: Hot surfaces
⎯ Part 2: Human contact with surfaces at moderate temperature [Technical Specification]
⎯ Part 3: Cold surfaces
iv © ISO 2006 – All rights reserved

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ISO 13732-1:2006(E)
Introduction
When human skin comes into contact with a hot solid surface, burns may occur. Whether or not they do
depends on a number of factors, the most important of which are
⎯ the temperature of the surface,
⎯ the material of the surface,
⎯ the period of contact between the skin and the surface,
⎯ the structure of the surface, and
⎯ the sensitivity of the human being who comes into contact with the surface (e.g. child or adult).
Other factors can also play a part but are of minor importance. In Annex A the scientific background is
presented and in the Bibliography publications concerning the objective are listed.
This part of ISO 13732 contains a collection of temperature threshold values for burns when the skin is in
contact with a hot solid surface (Clause 4). It also contains a method for the assessment of the risk of burning,
i.e. the application of the provided ergonomics data within a risk assessment procedure (Clause 5). A further
application of the data may be the specification of temperature limit values for hot surfaces. Such temperature
limit values may be specified in product standards or in regulations in order to prevent human beings
sustaining a burn when in contact with the surface of a hot product. Guidance on how to select reasonable
temperature limit values for that purpose is given in Clause 7. For different products with the same risk of
burning it is reasonable to establish identical surface temperature limit values. Therefore, this part of
ISO 13732 provides the possibility of harmonizing such temperature limit values for all kind of products.
Touching a hot surface may take place intentionally, e.g. to operate an electrically or gas powered machine or
tool, or unintentionally, when a person is near a hot object. The period of contact with the hot surface will be
different if the object is touched intentionally than if it is touched unintentionally. Considering human reaction
times and their distribution in the population, 0,5 s is the minimum applicable contact period for unintentional
touching of a hot surface for healthy adults on an acceptable safety level. For intentional touching the
minimum applicable contact period will be longer. For the application of this part of ISO 13732, it is essential
to select a contact period which best represents the real circumstances when a hot product is touched.
Guidance for such selection is given in Annex B.
The ergonomics data provided in this part of ISO 13732 are mainly based on scientific research and represent,
as far as is known, the behaviour of the human skin when in contact with a hot surface. Some of the data (e.g.
burn threshold data for very short contacts of 0,5 s) are not directly based on scientific research but are
deduced by extrapolation of the known threshold curves or by reasonable conclusion using scientific results.
The temperature threshold values provided in this part of ISO 13732 are valid for burning the skin when in
contact with hot surfaces. For the time being there are not sufficient scientific data available on the effects of
discomfort and pain to for them to be included in this part of ISO 13732. Some data for pain can be derived
from national standards (see Annexes A and the Bibliography). Research projects are planned for obtaining
data for discomfort and pain. When the results of these projects are available, this part of ISO 13732 may be
revised in order to also include discomfort and pain temperature threshold values. ISO 13732-2 deals also
with discomfort.
This part of ISO 13732 does not provide burn data on the skin that comes into contact with liquids or gases.
NOTE With the exception of water there are no such data available up to now. For water and liquids with similar heat
capacity and heat flow properties burn threshold values for bare metals can be chosen.
© ISO 2006 – All rights reserved v

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INTERNATIONAL STANDARD ISO 13732-1:2006(E)

Ergonomics of the thermal environment — Methods for the
assessment of human responses to contact with surfaces —
Part 1:
Hot surfaces
1 Scope
This part of ISO 13732 provides temperature threshold values for burns that occur when human skin is in
contact with a hot solid surface.
It also describes methods for the assessment of the risks of burning, when humans could or might touch hot
surfaces with their unprotected skin.
This part of ISO 13732 also gives guidance for cases where it is necessary to specify temperature limit values
for hot surfaces; it does not set surface temperature limit values.
NOTE 1 Such temperature limit values can be specified in specific product standards or in regulations in order to
prevent human beings sustaining burns when in contact with the hot surface of a product.
This part of ISO 13732 deals with contact periods of 0,5 s and longer.
It is applicable to contact when the surface temperature is essentially maintained during the contact (see 4.1).
It is not applicable if a large area of the skin (approximately 10 % or more of the skin of the whole body) can
be in contact with the hot surface. Neither does it apply to skin contact of more than 10 % of the head or
contact which could result in burns of vital areas of the face.
NOTE 2 In some cases, the results of contact with a hot surface can be more serious for the individual, for example:
⎯ burns resulting in the restriction of airways;
⎯ large burns (more than 10 % of the body surface) that can impair the circulation by fluid loss;
⎯ heating of a large proportion of the head or whole body that could lead to unacceptable heat strain even in the
absence of burning.
This part of ISO 13732 is applicable to the hot surfaces of all kind of objects: equipment, products, buildings,
natural objects, etc. For the purposes of simplification, it mentions only products; nevertheless, it applies to all
other objects as well.
It is applicable to products used in any environment, e.g. in the workplace, in the home.
It is applicable to hot surfaces of products that may be touched by healthy adults, children, elderly people and
also by people with physical disabilities.
It does not provide data for the protection against discomfort or pain.
© ISO 2006 – All rights reserved 1

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ISO 13732-1:2006(E)
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).
ISO 7726:1998, Ergonomics of the thermal environment — Instruments for measuring physical quantities
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
touchable surface
surface of a product that can be touched by a person’s skin
3.2
surface temperature
T
s
temperature of a material’s surface
NOTE Surface temperature is expressed in degrees Celsius (°C).
3.3
contact period
D
duration of contact of the skin with the surface
NOTE Contact period is expressed in seconds (s).
3.4
thermal inertia
product of density (ρ), thermal conductivity (K) and specific thermal capacity (c) of a material
3.5
burn threshold
surface temperature defining the boundary between no burn and a superficial partial thickness burn, caused
by contact of the skin with this surface for a specified contact period
NOTE Burns are classified into three levels, depending on severity.
⎯ superficial partial thickness burn:
in all but the most superficial burns, the epidermis is completely destroyed but the hair follicles and sebaceous glands
as well as the sweat glands are spared.
⎯ deep partial thickness burn:
a substantial part of the dermis and all sebaceous glands are destroyed and only the deeper parts of the hair follicles
or the sweat glands survive.
⎯ whole thickness burn:
the full thickness of the skin is destroyed and there are no surviving epithelial elements.
2 © ISO 2006 – All rights reserved

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ISO 13732-1:2006(E)
4 Burn thresholds
4.1 General
This clause provides surface temperature data for burn thresholds.
NOTE The occurrence of burning depends on the temperature of the skin and on the period of raised skin
temperature. The connection between skin temperature, the period of its influence and occurrence of burning has been
scientifically studied and is known (see Annex A). But it is not practicable by simple means to measure the temperature of
the skin during its contact with the hot surface of a product. Therefore, in this part of ISO 13732 it is not the temperature
values of the skin which are specified but the temperature values of hot surfaces of products which, when in contact with
the skin, lead to burns (the burn thresholds). The temperature of a surface of a product is simply measurable by
appropriate measuring facilities.
The surface temperatures which lead to burns during contact of the skin with a hot product depend on the
material of which the product consists, and on the period of the contact of the skin with the surface. This
relationship is presented in Figure 1, which shows this relationship for several groups of materials which have
similar heat conductivity properties and therefore similar burn thresholds.

Key
D contact period
T surface temperature
s
1 plastics
2 ceramics
3 metals
4 burn threshold
Figure 1 — Illustration of general relationship between burn threshold and contact period when hot
surface is touched by skin
© ISO 2006 – All rights reserved 3

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ISO 13732-1:2006(E)
A point on a burn threshold curve indicates, for a particular contact period, that surface temperature which lies
between non-injury of the skin and the onset of a superficial partial thickness burn when the skin comes into
contact with the hot surface. Surface temperature values lying below the curve in general do not lead to a burn.
Surface temperature values lying above the curve will lead to a burn of the skin (see also Annex A).
The illustrative Figure 1 only serves to provide a better understanding and does not accurately represent the
burn threshold data. The exact burn threshold values are to be taken from Figures 2, 5, 6 and 7 and Table 1.
For short contact periods the burn thresholds are not drawn as lines in the illustrative Figure 1 and the detailed
Figures 2, 5, 6 and 7, but as spreads. This takes into account the fact that for short contact periods the
knowledge of the temperature boundary between non-burning and the onset of burning is not complete. The
burn threshold depends on several factors, including thickness of the skin at the touching point, moisture of
the skin’s surface (sweating), contamination of the skin (e.g. grease), touching force differences between the
heat conductivity properties of materials which have been combined in one group, uncertainties of the
scientific determination of the burn threshold values (see also Annex A). However, these influences are
considered to be minor compared to the influence of the heat conductivity properties of the different material
groups.
For longer contact periods the uncertainties are less than for short contact periods. So for long contact periods
exact values for burn thresholds are specified. The differences in the values for different groups of materials
also disappear for long contact periods.
The data given presumes that the surface temperature is essentially maintained during the contact period
either by the mass of the product or by a heating source. These conditions will describe exposures which are
in conformity with the worst case.
4.2 Burn threshold data
4.2.1 Burn thresholds for contact periods between 0,5 s and 10 s
4.2.1.1 General
In the case of short contact (contact periods of 0,5 s to 10 s), the burn threshold spreads are not set in
numbers but are reflected in graphs in relation to the contact period. The burn thresholds of materials with
similar heat conductivity properties are combined to represent one spread.
4.2.1.2 Uncoated metals
The burn thresholds presented in Figure 2 are valid for the smooth surfaces of uncoated metals. In the case of
rough metal surfaces, however, the values may lie above those for smooth surfaces, but not more than 2 °C
beyond the upper limit of the indicated burn threshold spread.
4 © ISO 2006 – All rights reserved

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ISO 13732-1:2006(E)

Key
D contact period, s
T surface temperature, °C
s
1 no burn
2 burn threshold
3 burn
Figure 2 — Burn threshold spread when the skin in contact with hot, smooth surface made of bare
(uncoated) metal
4.2.1.3 Coated metals
The values for the effect of coating a metal are shown in Figures 3 and 4. The values reflect the rise of the
burn threshold above the burn threshold for uncoated metal. In order to obtain a burn threshold for coated
metal, the value for the rise of the burn threshold in Figure 3 or 4 and the burn threshold for the uncoated
metal in Figure 2 have to be added.
© ISO 2006 – All rights reserved 5

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ISO 13732-1:2006(E)

Key
D contact period, s
∆T rise in surface temperature, °C
s
a
50 µm.
b
100 µm.
c
150 µm.
Figure 3 — Rise in burn threshold spread from Figure 2 for metals coated by lac
of 50 µm, 100 µm and 150 µm

Key
D contact period, s
∆T rise in surface temperature, °C
s
a
Enamel (160 µm)/powder (60 µm).
b
Powder (90 µm).
c
Polyamide 11 or 12 (400 µm thickness).
Figure 4 — Rise in burn threshold spread from Figure 2 for metals coated by powder
(60 µm and 90 µm), enamel (160 µm) and polyamide 11 or 12 (400 µm thickness)
6 © ISO 2006 – All rights reserved

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ISO 13732-1:2006(E)
4.2.1.4 Ceramics, glass and stone materials
The burn threshold spread for ceramics, glass ceramics, glass, porcelain and stone materials (marble,
concrete) is shown in Figure 5.
The burn thresholds for marble and concrete lie towards the lower limit of the spread. Burn thresholds for
glass lie towards the upper limit of the spread.

Key
D contact period, s
T surface temperature, °C
s
1 no burn
2 burn threshold
3 burn
Figure 5 — Burn threshold spread when skin is contact with hot, smooth surface made of ceramics,
glass and stone materials
4.2.1.5 Plastics
The burn threshold spread for plastics (polyamide, acrylglass, polytetrafluorethylene, duroplastic) is shown in
Figure 6.
NOTE Plastics have very different levels of thermal conductivity, depending on chemical composition. The burn
threshold spread for most solid plastics is indicated in Figure 6. However, for plastics with heat conductivity properties
which differ markedly from those of the materials given here, the burn thresholds indicated cannot be used. For these
materials, burn thresholds have to be calculated, estimated or me
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