IEC 60335-2-81:2015

Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats

IEC 60335-2-81:2015 deals with the safety of electric foot warmers and heating mats for household and similar purposes, their rated voltage being not more than 250 V. Appliances not intended for normal household use but which nevertheless may be a source of danger to the public, such as appliances intended to be used by laymen in shops, in light industry and on farms, are within the scope of this standard. As far as is practicable, this standard deals with the common hazards presented by appliances that are encountered by all persons in and around the home. However, in general, it does not take into account persons (including children) whose physical, sensory or mental capabilities; or lack of experience and knowledge prevents them from using the appliance safely without supervision or instruction. It also does not take into account children playing with the appliance. It was established on the basis of the fifth edition (2010) of that standard. This third edition cancels and replaces the second edition published in 2002, its Amendment 1 (2007) and its Amendment 2 (2011). It constitutes a technical revision. The principal changes in this edition as compared with the second edition of IEC 60335-2-81 are as follows (minor changes are not listed):
- requirements for washable appliances (5.3, 7.1, 7.6, 7.12);
- requirements for controls in flexible cords (15.1.1, 24.2) and requirements for appliance inlets (22.105, 24.1.5, 29.1.3). The attention of National Committees is drawn to the fact that equipment manufacturers and testing organizations may need a transitional period following publication of a new, amended or revised IEC publication in which to make products in accordance with the new requirements and to equip themselves for conducting new or revised tests. It is the recommendation of the committee that the content of this standard be adopted for implementation nationally not earlier than 12 months or later than 36 months from the date of its publication. Key words: Foot warmer, heating element, heating mat
This publication is to be read in conjunction with IEC 60335-1:2010.

Appareils électrodomestiques et analogues - Sécurité - Partie 2-81: Exigences particulières pour les chancelières et les carpettes chauffantes électriques

L'IEC 60335-2-81:2015 traite de la sécurité des chancelières et des carpettes chauffantes électriques destinées à un usage domestique ou analogue, dont la tension assignée n'est pas supérieure à 250 V. Les appareils non destinés à un usage domestique normal mais qui néanmoins peuvent constituer une source de danger pour le public, tels que les appareils destinés à être utilisés par des usagers non avertis dans des magasins, chez les artisans et dans les fermes, relèvent du domaine d'application de la présente norme. Dans la mesure du possible, la présente norme traite des dangers ordinaires présentés par les appareils, encourus par tous les individus à l'intérieur et autour de l'habitation. Cependant, cette norme ne tient pas compte en general; des personnes (y compris des enfants) dont; les capacités physiques, sensorielles ou mentales; ou; le manque d'expérience et de connaissance; les empêchent d'utiliser l'appareil en toute sécurité sans surveillance ou instruction ou de l'utilisation de l'appareil comme jouet par des enfants. Elle a été établie sur la base de la cinquième édition (2010) de cette norme. Cette troisième édition annule et remplace la deuxième édition parue en 2002, son Amendement 1 (2007) et son Amendement 2 (2011). Elle constitue une révision technique. Par rapport à la deuxième édition de l'IEC 60335-2-81, les principales modifications indiquées ci-après ont été apportées dans la présente édition (les modifications mineures ne sont pas mentionnées):
- Exigences relatives aux appareils lavables (5.3, 7.1, 7.6, 7.12);
- Exigences relatives aux dispositifs de commande dans les câbles souples (15.1.1, 24.2) et les exigences relatives aux socles de connecteurs (22.105, 24.1.5, 29.1.3). L'attention des Comités nationaux est attirée sur le fait que les fabricants d'appareils et les organismes d'essai peuvent avoir besoin d'une période transitoire après la publication d'une nouvelle publication IEC, ou d'une publication amendée ou révisée, pour fabriquer des produits conformes aux nouvelles exigences et pour adapter leurs équipements aux nouveaux essais ou aux essais révisés. Le comité recommande que le contenu de cette publication soit entériné au niveau national au plus tôt 12 mois ou au plus tard 36 mois après la date de publication. Mots-Clés: chancelière, élément chauffant, carpette chauffante
Cette publication doit être lue conjointement avec la CEI 60335-1:2010.

General Information

• Status: Published
• Publication Date: 08-Apr-2015
• ICS: 13.120 - Domestic safety
• ICS: 97.100.10 - Electric heaters
• Technical Committee: TC 61 - Safety of household and similar electrical appliances
• Drafting Committee: MT 15 - TC 61/MT 15
• Current Stage: DELPUB - Deleted Publication
• Start Date: 08-Oct-2024
• Completion Date: 23-Jun-2023

Relations

• Amended By: IEC 60335-2-81:2015/AMD2:2020 - Amendment 2 - Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats
• Effective Date: 05-Sep-2023
• Amended By: IEC 60335-2-81:2015/AMD1:2017 - Amendment 1 - Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats
• Effective Date: 05-Sep-2023
• Revises: IEC 60335-2-81:2002 - Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats
• Effective Date: 05-Sep-2023
• Revised: IEC 60335-2-81:2024 - Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats
• Effective Date: 05-Sep-2023
• Revises: IEC 60335-2-81:2002/AMD2:2011 - Amendment 2 - Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats
• Effective Date: 05-Sep-2023
• Revises: IEC 60335-2-81:2002/AMD1:2007 - Amendment 1 - Household and similar electrical appliances - Safety - Part 2-81: Particular requirements for foot warmers and heating mats
• Effective Date: 05-Sep-2023

Overview

IEC 60335-2-81:2015 - “Household and similar electrical appliances – Safety – Part 2-81: Particular requirements for foot warmers and heating mats” specifies safety requirements and test methods for electric foot warmers, heating mats and associated heating elements with rated voltage up to 250 V. Intended for household and similar use (including laymen use in shops, light industry and farms), this part 2 standard supplements IEC 60335-1:2010 and addresses common hazards (electrical, thermal, mechanical, fire and radiation) under normal and certain abnormal conditions. It does not cover use by persons who cannot use the appliance safely without supervision (including young children playing with the appliance).

Key Topics

The standard focuses on practical safety and conformity topics, including:

• Scope and classification of appliances for household and similar use (rated ≤ 250 V).
• Marking and instructions: required labels, warnings and user guidance.
• Heating requirements: safe operation of heating elements and maximum temperatures (as referenced to Part 1).
• Washable appliances: added/updated requirements for appliances designed to be washable (clauses 5.3, 7.1, 7.6, 7.12).
• Controls in flexible cords and appliance inlets: updated construction and testing rules (clauses 15.1.1, 24.2, 22.105, 24.1.5, 29.1.3).
• Electrical safety tests: leakage current, electric strength at operating temperature, transient overvoltages, and moisture resistance.
• Mechanical and thermal tests: endurance, abnormal operation, mechanical strength, stability, resistance to heat and fire.
• Construction and components: internal wiring, terminals, earthing, clearances, creepage distances and component specifications.
• Specific test apparatus and methods: flexing tests for heating elements, spark ignition, pressure tests on connectors (illustrated in annex figures).

Applications and Users

This standard is essential for:

• Manufacturers and product designers of foot warmers, heating mats and heating elements - to design safe products and prepare technical documentation.
• Testing and certification laboratories - to perform compliance testing against the specified requirements and test methods.
• Regulatory bodies and compliance managers - to reference safety criteria for market approval and consumer protection.
• Safety engineers and quality assurance teams - to integrate safe construction, marking and user-instruction practices.

Practical applications include safer product design for consumer use, validated lab testing for market access, and reduced fire/electrical risks for portable heating products.

Related Standards

• IEC 60335-1:2010 (Part 1 - General requirements) - mandatory companion document.
• Other parts of the IEC 60335 series for appliances with multiple functions.

Keywords: IEC 60335-2-81:2015, foot warmer, heating mat, heating element, washable appliances, appliance inlets, controls in flexible cords.

Standards Content (Sample)

IEC 60335-2-81 ®
Edition 3.2 2020-06
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

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IEC 60335-2-81 ®
Edition 3.2 2020-06
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –

Part 2-81: Particular requirements for foot warmers and heating mats

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.120; 97.100.10 ISBN 978-2-8322-8466-7

IEC 60335-2-81 ®
Edition 3.2 2020-06
REDLINE VERSION
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

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CONTENTS
FOREWORD . 4
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General requirement . 9
5 General conditions for the tests . 9
6 Classification . 10
7 Marking and instructions . 10
8 Protection against access to live parts . 11
9 Starting of motor-operated appliances . 11
10 Power input and current . 11
11 Heating . 11
12 Void . 12
13 Leakage current and electric strength at operating temperature . 12
14 Transient overvoltages . 12
15 Moisture resistance . 12
16 Leakage current and electric strength . 12
17 Overload protection of transformers and associated circuits . 13
18 Endurance . 13
19 Abnormal operation . 13
20 Stability and mechanical hazards . 13
21 Mechanical strength . 13
22 Construction . 16
23 Internal wiring . 17
24 Components . 17
25 Supply connection and external flexible cords . 17
26 Terminals for external conductors . 17
27 Provision for earthing . 17
28 Screws and connections . 18
29 Clearances, creepage distances and solid insulation . 18
30 Resistance to heat and fire . 18
31 Resistance to rusting . 20
32 Radiation, toxicity and similar hazards . 20
Annexes . 25
Bibliography . 27

Figure 101 – Equipment for the flexing test for foot warmers . 21
Figure 102 – Equipment for flexing heating elements and internal wiring . 22
Figure 103 – Equipment for the spark ignition test . 23
Figure 104 – Details of the mask . 24

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Figure 105 – Apparatus for pressure test on connectors . 25

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
FOREWORD
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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.
This consolidated version of the official IEC Standard and its amendments has been
prepared for user convenience.
IEC 60335-2-81 edition 3.2 contains the third edition (2015-04) [documents 61/4841/FDIS
and 61/4896/RVD], its amendment 1 (2017-10) [documents 61/5292/CDV and
61/5378A/RVC] and its amendment 2 (2020-06) [documents 61/5934/CDV and
61/6007/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendments 1 and 2. Additions are in green text, deletions are in
strikethrough red text. A separate Final version with all changes accepted is available
in this publication.
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This part of International Standard IEC 60335 has been prepared by IEC technical committee
61: Safety of household and similar electrical appliances.
This third edition constitutes a technical revision.
The principal changes in this edition as compared with the second edition of IEC 60335-2-81
are as follows (minor changes are not listed):
• Requirements for washable appliances (5.3, 7.1, 7.6, 7.12);
• Requirements for controls in flexible cords (15.1.1, 24.2);
• Requirements for appliance inlets (22.105, 24.1.5, 29.1.3).
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fifth edition (2010) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for foot warmers and
heating mats.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies
as far as is reasonable. When this standard states “addition”, “modification” or “replacement”,
the relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of the base publication and its amendments will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.
A list of all parts of the IEC 60335 series, under the general title: Household and similar electrical appliances –
Safety, can be found on the IEC website.
The following differences exist in the countries indicated below.
– 3.1.9: Normal operation is different (USA)
– 6.1: Class 0 appliances are allowed if their rated voltage does not exceed 150 V (Japan)
– 6.1: Class 0 and class I appliances are allowed (USA)
– 7.6: Symbols not permitted to replace required text (USA)
– 11.8: Temperature limit is different (USA)
– 13.2: Method and limit is different (USA)
– 19.2: The test is different (USA)
– 21.101: The test is different (USA)
– 22.101: The tests are different (USA)

IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

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INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in
normal use taking into account the manufacturer's instructions. It also covers abnormal
situations that can be expected in practice and takes into account the way in which
electromagnetic phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply
mains. However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with
in Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of
the requirements and, if found to be substantially equivalent, may be considered to comply
with the standard.
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HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with the safety of electric foot warmers and heating mats
for household and similar purposes, their rated voltage being not more than 250 V.
Appliances not intended for normal household use but which nevertheless may be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by
appliances that are encountered by all persons in and around the home. However, in general,
it does not take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
NOTE 101 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be
necessary;
– in many countries additional requirements are specified by the national health authorities, the national
authorities responsible for the protection of labour, and similar authorities.
NOTE 102 This standard does not apply to
– appliances specifically intended for use under medical supervision;
– electric blankets and pads (IEC 60335-2-17);
– electrically heated carpets (IEC 60335-2-106);
– electrical heating appliances for breeding and rearing animals (IEC 60335-2-71).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60320-1:2001, Appliance couplers for household and similar general purposes – Part 1:
General requirements
IEC 60320-1:2001/AMD1:2007
________________
There exists a consolidated edition 2.1 (2007) that includes the second edition and its Amendment 1.

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IEC 60320-3, Appliance couplers for household and similar general purposes – Part 3:
Standard sheets and gauges
ISO 2439, Flexible cellular polymeric materials – Determination of hardness (indentation
technique)
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
Foot warmers are unfilled and placed on a horizontal surface.
Heating mats are placed on a horizontal surface and covered by a piece of expanded
polystyrene having dimensions approximately 300 mm × 150 mm × 50 mm.
3 3
NOTE 101 The density of the polystyrene is approximately 20 kg/m ± 5 kg/m .
3.101
foot warmer
appliance into which the user's feet are inserted in order to warm them
3.102
heating mat
appliance having an area not exceeding 0,5 m , on which the user's feet are placed in order
to warm them
3.103
heating element with PTC characteristics
heating element of the appliance consisting of a pair of conductors separated by conductive
material that has a rapid non-linear increase in resistance when the temperature is raised
through a particular range
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
A 15 m length of heating element or internal wiring is required for the tests of 21.102.
Twelve samples of the enclosure material of foot warmers, each having dimensions
200 mm × 100 mm, are required for the test of 30.101.
5.3 Addition:
Washable appliances are laundered twice in accordance with the instructions before testing is
started.
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The tests of Clauses 13, 15 and 16 are not carried out on Class III appliances having a rated
voltage not exceeding 24 V or on Class III constructions having a working voltage not
exceeding 24 V.
5.5 Addition:
If the appliance is provided with a detachable cover, the tests are carried out with or without
this cover, whichever is more unfavourable.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Appliances shall be class II or class III.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Washable appliances shall be marked with symbol ISO 7000-3114 (2012-04) and with symbol
ISO 7000-3124 (2012-04).
7.6 Addition:
[symbol ISO 7000-3114 (2012-04)] Do not dry clean

[symbol ISO 7000-3124 (2012-04)] Do not bleach

7.12 Addition:
The instructions shall state the substance of the following:
– the appliance is not to be used if there are signs of damage;
– the appliance is not to be used for warming animals;
– details regarding laundering or cleaning.
The instructions for foot warmers shall state that outdoor shoes must be removed before
use.
The instructions for heating mats shall state that the appliance has to be repaired or replaced
if the cover is worn. They shall explain how such wear can be observed.
The instructions for foot warmers intended to be used after preheating without supply and
incorporating an appliance inlet shall state that the cord set must be disconnected from the
supply after preheating.
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If symbol ISO 7000-3114 (2012-04) and symbol ISO 7000-3124 (2012-04) are used, their
meaning shall be explained.
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable except as follows.
10.101 The power input of appliances incorporating heating elements with PTC
characteristics shall significantly decrease with an increase in temperature.
Compliance is checked by the following test.
The appliance is supplied at rated voltage and operated under normal operation. The power
input shall have decreased by at least 50 % from the initial value when steady conditions are
established, any control operating during this period being short-circuited.
11 Heating
This clause of Part 1 is applicable except as follows:
11.2 Modification:
Appliances are placed as near as possible to one wall of the test corner and away from the
other wall.
11.3 Addition:
Thermocouples attached to the small blackened disks are also used for measuring the
temperature rise of the surface of the appliance.
11.7 Replacement:
Appliances are operated until steady conditions are established.
11.8 Modification:
When polyvinyl chloride is used for insulating heating elements, the temperature rise of the
insulation shall not exceed 80 K.
Addition:
The temperature rise of surfaces likely to be in contact with the user's feet shall not exceed
40 K.
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12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable except as follows.
13.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heating mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.1.1 Addition:
Appliances are subjected to the test of IEC 60529 as described in Subclause 14.2.1.
However, cord sets, switches and controls in the flexible cord are not subjected to the tests.
15.1.2 Addition:
Foot warmers are orientated so that the base of the appliance is in contact with the support.
Appliance inlets are covered before carrying out the test.
16 Leakage current and electric strength
This clause of Part 1 is applicable except as follows.
16.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heated mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.

+AMD2:2020 CSV © IEC 2020
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
18 Endurance
This clause of Part 1 is not applicable.
19 Abnormal operation
This clause of Part 1 is applicable except as follows.
19.2 Addition:
The appliance is covered partially or completely, whichever is more unfavourable, with a
sheet of open-cell polyether approximately 36 mm thick, having the following properties:
+2
– cell count 18 per cm;
+10
– specific mass 30 kg/m + %;
– hardness 120 N to 170 N at 40 % impression, measured according to ISO 2439.
If the foot warmer has a flexible part that covers the user's legs, this part is folded onto the
foot part before covering.
A plywood board, having dimensions approximately 500 mm × 500 mm × 20 mm, is placed on
top of the polyether sheet covering foot warmers.
19.4 Modification:
Heating mats are tested without being covered by the polystyrene block.
19.13 Addition:
The temperature rise of the insulation of heating elements shall not exceed 145 K.
20 Stability and mechanical hazards
This clause of Part 1 is applicable.
21 Mechanical strength
This clause of Part 1 is applicable except as follows.
21.1 Addition:
Foot warmers are also subjected to the test of 21.101.
21.2 Addition:
This requirement is not applicable to textiles and similar materials forming the enclosure.

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+AMD2:2020 CSV © IEC 2020
21.101 A plywood board, having dimensions approximately 300 mm × 150 mm × 20 mm with
rounded edges, is placed in the leg section of the foot warmer as shown in Figure 101. A
load of 30 kg is placed on the board, which is allowed to drop freely from a height of 200 mm
above the base, so that the leg section is flexed and the appliance is compressed between
the board and the supporting surface. The total mass of the board, its movable support and
the load is 30 kg. If the foot warmer does not have a leg section, the board is allowed to fall
onto the top surface.
The test is carried out 1 000 times at a rate of six times per minute.
The test shall not result in
– damage to the enclosure or displacement of heating elements to such an extent that
compliance with the standard is impaired;
– open-circuiting of heating elements or controls;
– breakage of more than 10 % of the strands of internal wiring;
– failure of constructional stitching, or breakage of glued or welded joints, to such an extent
that compliance with the standard is impaired.
NOTE An example of damage to the enclosure that could impair compliance with the standard is a tear in the
enclosure. Small holes in textiles that are not part of electrical insulation or do not provide protection against
moisture are ignored.
21.102 The insulation of heating elements and internal wiring shall retain adequate flexibility
and insulating characteristics throughout the life of the appliance.
Compliance is checked by the tests of 21.102.1 and by the tests of 21.102.2 and 21.102.3
when the insulation exceeds
– a temperature rise of 50 K during the test of Clause 11,
or
– a temperature rise of 110 K during the tests of Clause 19.
The tests are carried out on separate samples of heating element or internal wiring.
For the test of 21.102.1, one sample measuring approximately 4 m in length is required. For
the tests of 21.102.2, at least 12 samples are required, each having a length of 300 mm. For
the test of 21.102.3, 12 samples are required, each having a length of 300 mm.
21.102.1 The sample of heating element or internal wiring is attached to the equipment
shown in Figure 102. This equipment has a carrier with two pulleys, each having a groove
with a radius of 4 mm, the diameter at the base of the groove being 25 mm. The pulleys are
arranged so that the sample is horizontal where it passes between them.
NOTE 1 For samples not having a circular cross-section, the form of the groove in the pulley is suitably modified.
The sample is stretched over the pulleys, each end being loaded with a mass of 0,25 kg. If
necessary, the mass at each end is increased in steps of 0,1 kg in order to ensure that the
wires leaving the pulleys are parallel to each other. Restraining clamps are positioned so that
the pull is always applied by the mass in the opposite direction from which the carrier is
moving.
The carrier moves over a distance of 1 m with a constant speed of approximately 0,33 m/s for
25 000 cycles.
NOTE 2 A cycle is two movements, one in each direction.
The sample shall not break during the test.

+AMD2:2020 CSV © IEC 2020
NOTE 3 A monitoring current not exceeding 50 mA can be passed through the sample during the test.
For heating elements with PTC characteristics, the power input is measured before and
after the test. The measurement is made with the heating element suspended vertically in
free air and supplied at the rated voltage of the appliance. Both measurements are carried
out at the same ambient temperature and when the power input has stabilized. The power
input shall not increase during the test.
The sample is then immersed in water containing approximately 1 % NaCl. A d.c. voltage of
approximately 500 V is applied between the conductor and the saline solution.
The insulation resistance is measured 1 min after immersion and shall be at least 1 MΩ.
21.102.2 The conductors are pulled out from 12 samples of heating element or internal
wiring. If this is not possible, the insulation is slit longitudinally, the conductor is removed and
the insulation allowed to close.
Six of the samples are conditioned by suspending them vertically so that they hang freely in a
heating cabinet at a temperature of 125 °C ± 2 °C for 336 h. The samples are removed from
the cabinet and allowed to cool down to room temperature. When the material has stabilized,
the length of the samples is measured and shall not be less than 90 % of the original length.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The 12 samples are placed in a tensile machine, in turn, so that the length between the
clamps is at least 50 mm. The machine is operated at a uniform speed of
500 mm/min ± 50 mm/min. The force and elongation at the instant of rupture are determined.
Results obtained from any sample that ruptured at a force differing from the average value by
more than 10 %, and from samples that ruptured within a distance of 15 mm from the clamp,
are disregarded. Additional samples are tested in order to obtain 12 valid results.
The elongation of each of the unconditioned samples shall not be less than 100 % and their
tensile strength shall not be less than 8,75 MPa.
The average value of both the elongation and tensile strength of the conditioned samples
shall be not less than 75 % of the average value determined for the unconditioned samples.
21.102.3 A 10 mm length of insulation is removed from each end of 12 samples of heating
element or internal wiring.
Six of the samples are wound in a close helix of six turns on a metal mandrel having a
diameter approximately equal to the external diameter of the samples. Together with the
remaining six samples, they are placed in a heating cabinet at a temperature of 125 °C ± 2 °C
for 336 h. The samples are removed from the cabinet and allowed to cool down to room
temperature.
When the material has stabilized, the other six samples are also wound on the mandrel in the
same way.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.

– 16 – IEC 60335-2-81:2015+AMD1:2017
+AMD2:2020 CSV © IEC 2020
The mandrel is immersed for 1 h in water containing approximately 1 % NaCl. The samples
are then subjected to a test voltage of 1 000 V for class II appliances and 500 V for class III
appliances. The voltage is applied for 1 min between the conductors and the solution and
there shall be no breakdown.
The samples are unwound from the mandrel and inspection shall show that there are no
visible cracks.
21.103 Heating elements with PTC characteristics shall be resistant to crushing.
Compliance is checked by the following test.
The flexible part is fully supported by a piece of plywood 20 mm thick and supplied as
specified in 11.4. When steady conditions are established, the temperature of the heating
element is measured. A block having dimensions of 100 mm × 300 mm and a mass of 80 kg
is applied for 5 min to the surface in the most unfavourable place. After removing the block,
the appliance is again operated until steady conditions are established and the temperature of
the heating element is measured. The temperature of the heating element where the block
has been applied shall not have increased by more than 10 K.
NOTE 1 The edges of the block in contact with the flexible part are rounded.
NOTE 2 The most unfavourable place to apply the block is usually at a loop in the element.
22 Construction
This clause of Part 1 is applicable except as follows.
22.101 Appliances shall be constructed so that heating elements and internal wiring are
retained in their intended position. No part of the heating element shall cross over another
part of the heating element.
Crossing of internal wiring shall be avoided as far as possible. When this is unavoidable, the
wiring shall be secured in order to prevent any relative movement.
Compliance is checked by inspection.
22.102 There shall be no significant change in the position of the heating elements if the
stitching retaining them in position is broken.
Compliance is checked by inspection after breaking the thread in the most unfavourable
place.
22.103 The insulation of heating elements and internal wiring, except in class III
appliances, shall be integral with the conductor.
Compliance is checked by inspection.
22.104 Heating mats shall be constructed so that exposure of insulation of heating element
and internal wiring shall be readily observed.
Compliance is checked by inspection after removing other materials such as carpet pile. The
colours of the insulation shall be different from the colours of the other materials.
22.105 The appliance inlet in foot warmers shall be positioned so that the connector is not
in contact with the floor.
+AMD2:2020 CSV © IEC 2020
Compliance is checked by inspection.
23 Internal wiring
This clause of Part 1 is applicable.
24 Components
This clause of Part 1 is applicable except as follows.
24.1.3 Modification:
Switches are tested for 6 000 cycles of operation.
24.1.4 Modification:
Thermostats are operated for 100 000 cycles of operation and self-resetting thermal cut-
outs for 10 000 cycles of operation.
24.1.5 Addition:
All parts of IEC 60320-1 are applicable except for those that make reference to the
connectors in the standard sheets of IEC 60320-1 IEC 60320-3.
24.2 Modification:
Appliances may be fitted with switches and controls in flexible cords.
25 Supply connection and external flexible cords
This clause of Part 1 is applicable except as follows.
25.5 Addition:
Type Z attachment is allowed.
25.14 Addition:
The test is applicable to appliances fitted with a non-detachable flexible cord. It also applies
to switches and controls fitted in the flexible cord.
25.15 Modification:
The pull force is increased to 60 N.
26 Terminals for external conductors
This clause of Part 1 is applicable.
27 Provision for earthing
This clause of Part 1 is applicable.

– 18 – IEC 60335-2-81:2015+AMD1:2017
+AMD2:2020 CSV © IEC 2020
28 Screws and connections
This clause of Part 1 is applicable.
29 Clearances, creepage distances and solid insulation
This clause of Part 1 is applicable except as follows.
29.1.3 Addition:
The clearance between the engagement face and contact tubes of appliance couplers used
for supplying the flexible part shall be at least 3,5 mm.
29.2 Addition:
The microenvironment is pollution degree 3 unless the insulation is enclosed or located so
that it is unlikely to be exposed to pollution during normal use of the appliance.
29.3 Addition:
The requirement does not apply to the part containing heating elements.
30 Resistance to heat and fire
This clause of Part 1 is applicable except as follows.
30.1 Addition:
The test is not applied to enclosures that are likely to be flexed in normal use.
Modification:
Parts of resilient plastic material are subjected to the pressure test of 24.1.3 of
IEC 60320-1:2001 instead of the ball pressure test of IEC 60695-10-2.
NOTE 101 An example of a part of resilient plastic material is a connection block.
Connectors of resilient plastic material are not subjected to the ball pressure test but are
subjected to a pressure test using an apparatus similar to that shown in Figure 105, the test
being made in a heating cabinet at a temperature of 100 °C ± 2 °C.
The specimen is clamped between steel jaws, having a cylindrical face of 25 mm radius, a
width of 15 mm and a length of 50 mm. The corners are rounded with a radius of 2,5 mm.
The specimen is clamped in such a way that the jaws press against it in the area where it is
gripped in normal use, the centre line of the jaws coinciding as nearly as possible with the
centre of this area.
The force applied through the jaws is 20 N.
After 1 h, the jaws are removed and the specimen shall show no damage within the meaning
of this document.
+AMD2:2020 CSV © IEC 2020
30.2 Modification:
The test is not carried out on textiles and similar materials forming the enclosure of foot
warmers.
30.2.2 Not applicable.
30.2.3.2 Addition:
The needle-flame test is not carried out on textile materials.
30.101 Textiles and similar materials forming the enclosure of foot warmers shall be
adequately resistant to ignition.
Compliance is checked by a spark ignition test that is carried out on six samples of the
material. Each sample has dimensions approximately 200 mm × 100 mm. Any pieces of
heating element and trimming are removed from the samples.
The test fixture, as shown in Figure 103, has two brass electrodes 3 mm in diameter that are
supported by brass pillars mounted on a base plate of insulating material so that their axes
are aligned. The base plate also supports a platform of insulating material, having dimensions
× 100 mm, and located centrally between the brass pillars. Provision is made for
of 100 mm
the height of the platform to be adjusted.
One of the electrodes is fixed in position while the other electrode is movable, thus allowing
the sample to be inserted. The tip of the fixed electrode has an angle of 45°. The electrode is
positioned so that the point furthest from the brass pillar is at the top and at a distance of
approximately 3 mm from the centre of the platform. The movable electrode has a flat end.
The lower member of a two-part hardwood mask, as shown in detail A of Figure 103, is placed
on the adjustable platform
...

IEC 60335-2-81 ®
Edition 3.1 2017-10
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

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IEC 60335-2-81 ®
Edition 3.1 2017-10
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Safety –

Part 2-81: Particular requirements for foot warmers and heating mats

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.120, 97.100.10 ISBN 978-2-8322-4927-7

IEC 60335-2-81 ®
Edition 3.1 2017-10
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

– 2 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
CONTENTS
FOREWORD . 3
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 General requirement . 8
5 General conditions for the tests . 8
6 Classification . 9
7 Marking and instructions . 9
8 Protection against access to live parts . 10
9 Starting of motor-operated appliances . 10
10 Power input and current . 10
11 Heating . 10
12 Void . 11
13 Leakage current and electric strength at operating temperature . 11
14 Transient overvoltages . 11
15 Moisture resistance . 11
16 Leakage current and electric strength . 11
17 Overload protection of transformers and associated circuits . 11
18 Endurance . 11
19 Abnormal operation . 12
20 Stability and mechanical hazards . 12
21 Mechanical strength . 12
22 Construction . 15
23 Internal wiring . 15
24 Components . 16
25 Supply connection and external flexible cords . 16
26 Terminals for external conductors . 16
27 Provision for earthing . 16
28 Screws and connections . 16
29 Clearances, creepage distances and solid insulation . 17
30 Resistance to heat and fire . 17
31 Resistance to rusting . 19
32 Radiation, toxicity and similar hazards . 19
Annexes . 23
Bibliography . 24

Figure 101 – Equipment for the flexing test for foot warmers . 19
Figure 102 – Equipment for flexing heating elements and internal wiring . 20
Figure 103 – Equipment for the spark ignition test . 21
Figure 104 – Details of the mask . 22

© IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
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, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for 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
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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.
This consolidated version of the official IEC Standard and its amendment has been prepared
for user convenience.
IEC 60335-2-81 edition 3.1 contains the third edition (2015-04) [documents 61/4841/FDIS and
61/4896/RVD] and its amendment 1 (2017-10) [documents 61/5292/CDV and 61/5378A/RVC].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions are in green text, deletions are in strikethrough red text. A
separate Final version with all changes accepted is available in this publication.

– 4 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
This part of International Standard IEC 60335 has been prepared by IEC technical
committee 61: Safety of household and similar electrical appliances.
This third edition constitutes a technical revision.
The principal changes in this edition as compared with the second edition of IEC 60335-2-81
are as follows (minor changes are not listed):
• Requirements for washable appliances (5.3, 7.1, 7.6, 7.12);
• Requirements for controls in flexible cords (15.1.1, 24.2);
• Requirements for appliance inlets (22.105, 24.1.5, 29.1.3).
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fifth edition (2010) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for foot warmers and
heating mats.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies
as far as is reasonable. When this standard states “addition”, “modification” or “replacement”,
the relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
© IEC 2017
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.
A list of all parts of the IEC 60335 series, under the general title: Household and similar electrical appliances –
Safety, can be found on the IEC website.
The following differences exist in the countries indicated below.
– 3.1.9: Normal operation is different (USA)
– 6.1: Class 0 appliances are allowed if their rated voltage does not exceed 150 V (Japan)
– 6.1: Class 0 and class I appliances are allowed (USA)
– 7.6: Symbols not permitted to replace required text (USA)
– 11.8: Temperature limit is different (USA)
– 13.2: Method and limit is different (USA)
– 19.2: The test is different (USA)
– 21.101: The test is different (USA)
– 22.101: The tests are different (USA)
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

– 6 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in
normal use taking into account the manufacturer's instructions. It also covers abnormal
situations that can be expected in practice and takes into account the way in which
electromagnetic phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply
mains. However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with
in Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of
the requirements and, if found to be substantially equivalent, may be considered to comply
with the standard.
© IEC 2017
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with the safety of electric foot warmers and heating mats
for household and similar purposes, their rated voltage being not more than 250 V.
Appliances not intended for normal household use but which nevertheless may be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by
appliances that are encountered by all persons in and around the home. However, in general,
it does not take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
NOTE 101 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be
necessary;
– in many countries additional requirements are specified by the national health authorities, the national
authorities responsible for the protection of labour, and similar authorities.
NOTE 102 This standard does not apply to
– appliances specifically intended for use under medical supervision;
– electric blankets and pads (IEC 60335-2-17);
– electrically heated carpets (IEC 60335-2-106);
– electrical heating appliances for breeding and rearing animals (IEC 60335-2-71).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60320-1:2001, Appliance couplers for household and similar general purposes – Part 1:
General requirements
IEC 60320-1:2001/AMD1:2007
________________
There exists a consolidated edition 2.1 (2007) that includes the second edition and its Amendment 1.

– 8 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
ISO 2439, Flexible cellular polymeric materials – Determination of hardness (indentation
technique)
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
Foot warmers are unfilled and placed on a horizontal surface.
Heating mats are placed on a horizontal surface and covered by a piece of expanded
polystyrene having dimensions approximately 300 mm × 150 mm × 50 mm.
3 3
NOTE 101 The density of the polystyrene is approximately 20 kg/m ± 5 kg/m .
3.101
foot warmer
appliance into which the user's feet are inserted in order to warm them
3.102
heating mat
appliance having an area not exceeding 0,5 m , on which the user's feet are placed in order
to warm them
3.103
heating element with PTC characteristics
heating element of the appliance consisting of a pair of conductors separated by conductive
material that has a rapid non-linear increase in resistance when the temperature is raised
through a particular range
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
A 15 m length of heating element or internal wiring is required for the tests of 21.102.
Twelve samples of the enclosure material of foot warmers, each having dimensions
200 mm × 100 mm, are required for the test of 30.101.
5.3 Addition:
Washable appliances are laundered twice in accordance with the instructions before testing is
started.
The tests of Clauses 13, 15 and 16 are not carried out on Class III appliances having a rated
voltage not exceeding 24 V or on Class III constructions having a working voltage not
exceeding 24 V.
© IEC 2017
5.5 Addition:
If the appliance is provided with a detachable cover, the tests are carried out with or without
this cover, whichever is more unfavourable.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Appliances shall be class II or class III.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Washable appliances shall be marked with symbol ISO 7000-3114 (2012-04) and with symbol
ISO 7000-3124 (2012-04).
7.6 Addition:
[symbol ISO 7000-3114 (2012-04)] Do not dry clean

[symbol ISO 7000-3124 (2012-04)] Do not bleach

7.12 Addition:
The instructions shall state the substance of the following:
– the appliance is not to be used if there are signs of damage;
– the appliance is not to be used for warming animals;
– details regarding laundering or cleaning.
The instructions for foot warmers shall state that outdoor shoes must be removed before
use.
The instructions for heating mats shall state that the appliance has to be repaired or replaced
if the cover is worn. They shall explain how such wear can be observed.
The instructions for foot warmers intended to be used after preheating without supply and
incorporating an appliance inlet shall state that the cord set must be disconnected from the
supply after preheating.
If symbol ISO 7000-3114 (2012-04) and symbol ISO 7000-3124 (2012-04) are used, their
meaning shall be explained.
– 10 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable except as follows.
10.101 The power input of appliances incorporating heating elements with PTC
characteristics shall significantly decrease with an increase in temperature.
Compliance is checked by the following test.
The appliance is supplied at rated voltage and operated under normal operation. The power
input shall have decreased by at least 50 % from the initial value when steady conditions are
established, any control operating during this period being short-circuited.
11 Heating
This clause of Part 1 is applicable except as follows:
11.2 Modification:
Appliances are placed as near as possible to one wall of the test corner and away from the
other wall.
11.3 Addition:
Thermocouples attached to the small blackened disks are also used for measuring the
temperature rise of the surface of the appliance.
11.7 Replacement:
Appliances are operated until steady conditions are established.
11.8 Modification:
When polyvinyl chloride is used for insulating heating elements, the temperature rise of the
insulation shall not exceed 80 K.
Addition:
The temperature rise of surfaces likely to be in contact with the user's feet shall not exceed
40 K.
© IEC 2017
12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable except as follows.
13.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heating mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.1.1 Addition:
Appliances are subjected to the test of IEC 60529 as described in Subclause 14.2.1.
However, cord sets, switches and controls in the flexible cord are not subjected to the tests.
16 Leakage current and electric strength
This clause of Part 1 is applicable except as follows.
16.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heated mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
18 Endurance
This clause of Part 1 is not applicable.

– 12 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
19 Abnormal operation
This clause of Part 1 is applicable except as follows.
19.2 Addition:
The appliance is covered partially or completely, whichever is more unfavourable, with a
sheet of open-cell polyether approximately 36 mm thick, having the following properties:
+2
– cell count 18 per cm;
+10
– specific mass 30 kg/m + %;
– hardness 120 N to 170 N at 40 % impression, measured according to ISO 2439.
If the foot warmer has a flexible part that covers the user's legs, this part is folded onto the
foot part before covering.
A plywood board, having dimensions approximately 500 mm × 500 mm × 20 mm, is placed on
top of the polyether sheet covering foot warmers.
19.4 Modification:
Heating mats are tested without being covered by the polystyrene block.
19.13 Addition:
The temperature rise of the insulation of heating elements shall not exceed 145 K.
20 Stability and mechanical hazards
This clause of Part 1 is applicable.
21 Mechanical strength
This clause of Part 1 is applicable except as follows.
21.1 Addition:
Foot warmers are also subjected to the test of 21.101.
21.2 Addition:
This requirement is not applicable to textiles and similar materials forming the enclosure.
21.101 A plywood board, having dimensions approximately 300 mm × 150 mm × 20 mm with
rounded edges, is placed in the leg section of the foot warmer as shown in Figure 101. A
load of 30 kg is placed on the board, which is allowed to drop freely from a height of 200 mm
above the base, so that the leg section is flexed and the appliance is compressed between
the board and the supporting surface. The total mass of the board, its movable support and
the load is 30 kg. If the foot warmer does not have a leg section, the board is allowed to fall
onto the top surface.
The test is carried out 1 000 times at a rate of six times per minute.

© IEC 2017
The test shall not result in
– damage to the enclosure or displacement of heating elements to such an extent that
compliance with the standard is impaired;
– open-circuiting of heating elements or controls;
– breakage of more than 10 % of the strands of internal wiring;
– failure of constructional stitching, or breakage of glued or welded joints, to such an extent
that compliance with the standard is impaired.
NOTE An example of damage to the enclosure that could impair compliance with the standard is a tear in the
enclosure. Small holes in textiles that are not part of electrical insulation or do not provide protection against
moisture are ignored.
21.102 The insulation of heating elements and internal wiring shall retain adequate flexibility
and insulating characteristics throughout the life of the appliance.
Compliance is checked by the tests of 21.102.1 and by the tests of 21.102.2 and 21.102.3
when the insulation exceeds
– a temperature rise of 50 K during the test of Clause 11,
or
– a temperature rise of 110 K during the tests of Clause 19.
The tests are carried out on separate samples of heating element or internal wiring.
For the test of 21.102.1, one sample measuring approximately 4 m in length is required. For
the tests of 21.102.2, at least 12 samples are required, each having a length of 300 mm. For
the test of 21.102.3, 12 samples are required, each having a length of 300 mm.
21.102.1 The sample of heating element or internal wiring is attached to the equipment
shown in Figure 102. This equipment has a carrier with two pulleys, each having a groove
with a radius of 4 mm, the diameter at the base of the groove being 25 mm. The pulleys are
arranged so that the sample is horizontal where it passes between them.
NOTE 1 For samples not having a circular cross-section, the form of the groove in the pulley is suitably modified.
The sample is stretched over the pulleys, each end being loaded with a mass of 0,25 kg. If
necessary, the mass at each end is increased in steps of 0,1 kg in order to ensure that the
wires leaving the pulleys are parallel to each other. Restraining clamps are positioned so that
the pull is always applied by the mass in the opposite direction from which the carrier is
moving.
The carrier moves over a distance of 1 m with a constant speed of approximately 0,33 m/s for
25 000 cycles.
NOTE 2 A cycle is two movements, one in each direction.
The sample shall not break during the test.
NOTE 3 A monitoring current not exceeding 50 mA can be passed through the sample during the test.
For heating elements with PTC characteristics, the power input is measured before and
after the test. The measurement is made with the heating element suspended vertically in
free air and supplied at the rated voltage of the appliance. Both measurements are carried
out at the same ambient temperature and when the power input has stabilized. The power
input shall not increase during the test.
The sample is then immersed in water containing approximately 1 % NaCl. A d.c. voltage of
approximately 500 V is applied between the conductor and the saline solution.

– 14 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
The insulation resistance is measured 1 min after immersion and shall be at least 1 MΩ.
21.102.2 The conductors are pulled out from 12 samples of heating element or internal
wiring. If this is not possible, the insulation is slit longitudinally, the conductor is removed and
the insulation allowed to close.
Six of the samples are conditioned by suspending them vertically so that they hang freely in a
heating cabinet at a temperature of 125 °C ± 2 °C for 336 h. The samples are removed from
the cabinet and allowed to cool down to room temperature. When the material has stabilized,
the length of the samples is measured and shall not be less than 90 % of the original length.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The 12 samples are placed in a tensile machine, in turn, so that the length between the
clamps is at least 50 mm. The machine is operated at a uniform speed of
500 mm/min ± 50 mm/min. The force and elongation at the instant of rupture are determined.
Results obtained from any sample that ruptured at a force differing from the average value by
more than 10 %, and from samples that ruptured within a distance of 15 mm from the clamp,
are disregarded. Additional samples are tested in order to obtain 12 valid results.
The elongation of each of the unconditioned samples shall not be less than 100 % and their
tensile strength shall not be less than 8,75 MPa.
The average value of both the elongation and tensile strength of the conditioned samples
shall be not less than 75 % of the average value determined for the unconditioned samples.
21.102.3 A 10 mm length of insulation is removed from each end of 12 samples of heating
element or internal wiring.
Six of the samples are wound in a close helix of six turns on a metal mandrel having a
diameter approximately equal to the external diameter of the samples. Together with the
remaining six samples, they are placed in a heating cabinet at a temperature of 125 °C ± 2 °C
for 336 h. The samples are removed from the cabinet and allowed to cool down to room
temperature.
When the material has stabilized, the other six samples are also wound on the mandrel in the
same way.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The mandrel is immersed for 1 h in water containing approximately 1 % NaCl. The samples
are then subjected to a test voltage of 1 000 V for class II appliances and 500 V for class III
appliances. The voltage is applied for 1 min between the conductors and the solution and
there shall be no breakdown.
The samples are unwound from the mandrel and inspection shall show that there are no
visible cracks.
21.103 Heating elements with PTC characteristics shall be resistant to crushing.

© IEC 2017
Compliance is checked by the following test.
The flexible part is fully supported by a piece of plywood 20 mm thick and supplied as
specified in 11.4. When steady conditions are established, the temperature of the heating
element is measured. A block having dimensions of 100 mm × 300 mm and a mass of 80 kg
is applied for 5 min to the surface in the most unfavourable place. After removing the block,
the appliance is again operated until steady conditions are established and the temperature of
the heating element is measured. The temperature of the heating element where the block
has been applied shall not have increased by more than 10 K.
NOTE 1 The edges of the block in contact with the flexible part are rounded.
NOTE 2 The most unfavourable place to apply the block is usually at a loop in the element.
22 Construction
This clause of Part 1 is applicable except as follows.
22.101 Appliances shall be constructed so that heating elements and internal wiring are
retained in their intended position. No part of the heating element shall cross over another
part of the heating element.
Crossing of internal wiring shall be avoided as far as possible. When this is unavoidable, the
wiring shall be secured in order to prevent any relative movement.
Compliance is checked by inspection.
22.102 There shall be no significant change in the position of the heating elements if the
stitching retaining them in position is broken.
Compliance is checked by inspection after breaking the thread in the most unfavourable
place.
22.103 The insulation of heating elements and internal wiring, except in class III
appliances, shall be integral with the conductor.
Compliance is checked by inspection.
22.104 Heating mats shall be constructed so that exposure of insulation of heating element
and internal wiring shall be readily observed.
Compliance is checked by inspection after removing other materials such as carpet pile. The
colours of the insulation shall be different from the colours of the other materials.
22.105 The appliance inlet in foot warmers shall be positioned so that the connector is not
in contact with the floor.
Compliance is checked by inspection.
23 Internal wiring
This clause of Part 1 is applicable.

– 16 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
24 Components
This clause of Part 1 is applicable except as follows.
24.1.3 Modification:
Switches are tested for 6 000 cycles of operation.
24.1.4 Modification:
Thermostats are operated for 100 000 cycles of operation and self-resetting thermal cut-
outs for 10 000 cycles of operation.
24.1.5 Addition:
All parts of IEC 60320-1 are applicable except for those that make reference to the
connectors in the standard sheets of IEC 60320-1.
24.2 Modification:
Appliances may be fitted with switches and controls in flexible cords.
25 Supply connection and external flexible cords
This clause of Part 1 is applicable except as follows.
25.5 Addition:
Type Z attachment is allowed.
25.14 Addition:
The test is applicable to appliances fitted with a non-detachable flexible cord. It also applies
to switches and controls fitted in the flexible cord.
25.15 Modification:
The pull force is increased to 60 N.
26 Terminals for external conductors
This clause of Part 1 is applicable.
27 Provision for earthing
This clause of Part 1 is applicable.
28 Screws and connections
This clause of Part 1 is applicable.

© IEC 2017
29 Clearances, creepage distances and solid insulation
This clause of Part 1 is applicable except as follows.
29.1.3 Addition:
The clearance between the engagement face and contact tubes of appliance couplers used
for supplying the flexible part shall be at least 3,5 mm.
29.2 Addition:
The microenvironment is pollution degree 3 unless the insulation is enclosed or located so
that it is unlikely to be exposed to pollution during normal use of the appliance.
29.3 Addition:
The requirement does not apply to the part containing heating elements.
30 Resistance to heat and fire
This clause of Part 1 is applicable except as follows.
30.1 Addition:
The test is not applied to enclosures that are likely to be flexed in normal use.
Modification:
Parts of resilient plastic material are subjected to the pressure test of 24.1.3 of
IEC 60320-1:2001 instead of the ball pressure test of IEC 60695-10-2.
NOTE 101 An example of a part of resilient plastic material is a connection block.
30.2 Modification:
The test is not carried out on textiles and similar materials forming the enclosure of foot
warmers.
30.2.2 Not applicable.
30.2.3.2 Addition:
The needle-flame test is not carried out on textile materials.
30.101 Textiles and similar materials forming the enclosure of foot warmers shall be
adequately resistant to ignition.
Compliance is checked by a spark ignition test that is carried out on six samples of the
material. Each sample has dimensions approximately 200 mm × 100 mm. Any pieces of
heating element and trimming are removed from the samples.
The test fixture, as shown in Figure 103, has two brass electrodes 3 mm in diameter that are
supported by brass pillars mounted on a base plate of insulating material so that their axes
are aligned. The base plate also supports a platform of insulating material, having dimensions

– 18 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
of 100 mm × 100 mm, and located centrally between the brass pillars. Provision is made for
the height of the platform to be adjusted.
One of the electrodes is fixed in position while the other electrode is movable, thus allowing
the sample to be inserted. The tip of the fixed electrode has an angle of 45°. The electrode is
positioned so that the point furthest from the brass pillar is at the top and at a distance of
approximately 3 mm from the centre of the platform. The movable electrode has a flat end.
The lower member of a two-part hardwood mask, as shown in detail A of Figure 103, is placed
on the adjustable platform in the position indicated.
The test fixture, including the upper member of the mask as shown in detail B of Figure 103,
is placed in a heating cabinet having a door with an inspection window, air being circulated by
natural convection. The electrodes are connected in series with an adjustable non-inductive
resistor to a supply having a sinusoidal output voltage of 10 kV and a characteristic such that
the output voltage does not decrease by more than 100 V when a current of 1 mA is flowing.
The temperature of the heating cabinet is raised to 65 °C ± 2 °C. The electrodes are then
short-circuited and the resistor adjusted so that a current of 1 mA flows. The supply is then
disconnected and the samples are placed in the cabinet for a period of 3 h.
Without removing the fixture from the heating cabinet, the movable electrode is withdrawn and
one sample is pulled over the fixed electrode so that the electrode is situated centrally in the
space normally occupied by the heating element. The sample is adjusted so that its end is
approximately level with the edge of the adjustable platform. The movable electrode is then
inserted into the other end of the element space and is fixed so that the distance between the
electrodes is 6,0 mm ± 0,1 mm. The sample is smoothed out and t
...

IEC 60335-2-81 ®
Edition 3.0 2015-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-81: Exigences particulières pour les chancelières et les carpettes
chauffantes électriques
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IEC 60335-2-81 ®
Edition 3.0 2015-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Household and similar electrical appliances – Safety –

Part 2-81: Particular requirements for foot warmers and heating mats

Appareils électrodomestiques et analogues – Sécurité –

Partie 2-81: Exigences particulières pour les chancelières et les carpettes

chauffantes électriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.120, 97.100.10 ISBN 978-2-8322-2597-4

– 2 – IEC 60335-2-81:2015 © IEC 2015
CONTENTS
FOREWORD . 4
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General requirement . 9
5 General conditions for the tests . 9
6 Classification . 10
7 Marking and instructions . 10
8 Protection against access to live parts . 11
9 Starting of motor-operated appliances . 11
10 Power input and current . 11
11 Heating . 11
12 Void . 12
13 Leakage current and electric strength at operating temperature . 12
14 Transient overvoltages . 12
15 Moisture resistance . 12
16 Leakage current and electric strength . 12
17 Overload protection of transformers and associated circuits . 12
18 Endurance . 12
19 Abnormal operation . 13
20 Stability and mechanical hazards . 13
21 Mechanical strength . 13
22 Construction . 16
23 Internal wiring . 16
24 Components . 17
25 Supply connection and external flexible cords . 17
26 Terminals for external conductors . 17
27 Provision for earthing . 17
28 Screws and connections . 17
29 Clearances, creepage distances and solid insulation . 17
30 Resistance to heat and fire . 18
31 Resistance to rusting . 20
32 Radiation, toxicity and similar hazards . 20
Annexes . 24
Bibliography . 25

Figure 101 – Equipment for the flexing test for foot warmers . 20
Figure 102 – Equipment for flexing heating elements and internal wiring . 21
Figure 103 – Equipment for the spark ignition test . 22
Figure 104 – Details of the mask . 23

– 4 – IEC 60335-2-81:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This part of International Standard IEC 60335 has been prepared by IEC technical committee
61: Safety of household and similar electrical appliances.
This third edition cancels and replaces the second edition published in 2002, its Amendment 1
(2007) and its Amendment 2 (2011). It constitutes a technical revision.
The principal changes in this edition as compared with the second edition of IEC 60335-2-81
are as follows (minor changes are not listed):
• Requirements for washable appliances (5.3, 7.1, 7.6, 7.12);
• Requirements for controls in flexible cords (15.1.1, 24.2);
• Requirements for appliance inlets (22.105, 24.1.5, 29.1.3).

The text of this standard is based on the following documents:
FDIS Report on voting
61/4841/FDIS 61/4896/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fifth edition (2010) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for foot warmers and
heating mats.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies
as far as is reasonable. When this standard states “addition”, “modification” or “replacement”,
the relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.
A list of all parts of the IEC 60335 series, under the general title: Household and similar
electrical appliances – Safety, can be found on the IEC website.
The following differences exist in the countries indicated below.

– 6 – IEC 60335-2-81:2015 © IEC 2015
– 3.1.9: Normal operation is different (USA)
– 6.1: Class 0 appliances are allowed if their rated voltage does not exceed 150 V (Japan)
– 6.1: Class 0 and class I appliances are allowed (USA)
– 7.6: Symbols not permitted to replace required text (USA)
– 11.8: Temperature limit is different (USA)
– 13.2: Method and limit is different (USA)
– 19.2: The test is different (USA)
– 21.101: The test is different (USA)
– 22.101: The tests are different (USA)

INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in
normal use taking into account the manufacturer's instructions. It also covers abnormal
situations that can be expected in practice and takes into account the way in which
electromagnetic phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply
mains. However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with
in Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of
the requirements and, if found to be substantially equivalent, may be considered to comply
with the standard.
– 8 – IEC 60335-2-81:2015 © IEC 2015
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with the safety of electric foot warmers and heating mats
for household and similar purposes, their rated voltage being not more than 250 V.
Appliances not intended for normal household use but which nevertheless may be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by
appliances that are encountered by all persons in and around the home. However, in general,
it does not take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
NOTE 101 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be
necessary;
– in many countries additional requirements are specified by the national health authorities, the national
authorities responsible for the protection of labour, and similar authorities.
NOTE 102 This standard does not apply to
– appliances specifically intended for use under medical supervision;
– electric blankets and pads (IEC 60335-2-17);
– electrically heated carpets;
– electrical heating appliances for breeding and rearing animals (IEC 60335-2-71).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60320-1:2001, Appliance couplers for household and similar general purposes – Part 1:
General requirements
IEC 60320-1:2001/AMD1:2007
________________
There exists a consolidated edition 2.1 (2007) that includes the second edition and its Amendment 1.

ISO 2439, Flexible cellular polymeric materials – Determination of hardness (indentation
technique)
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
Foot warmers are unfilled and placed on a horizontal surface.
Heating mats are placed on a horizontal surface and covered by a piece of expanded
polystyrene having dimensions approximately 300 mm × 150 mm × 50 mm.
3 3
NOTE 101 The density of the polystyrene is approximately 20 kg/m ± 5 kg/m .
3.101
foot warmer
appliance into which the user's feet are inserted in order to warm them
3.102
heating mat
appliance having an area not exceeding 0,5 m , on which the user's feet are placed in order
to warm them
3.103
heating element with PTC characteristics
heating element of the appliance consisting of a pair of conductors separated by conductive
material that has a rapid non-linear increase in resistance when the temperature is raised
through a particular range
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
A 15 m length of heating element or internal wiring is required for the tests of 21.102.
Twelve samples of the enclosure material of foot warmers, each having dimensions
200 mm × 100 mm, are required for the test of 30.101.
5.3 Addition:
Washable appliances are laundered twice in accordance with the instructions before testing is
started.
The tests of Clauses 13, 15 and 16 are not carried out on Class III appliances having a rated
voltage not exceeding 24 V or on Class III constructions having a working voltage not
exceeding 24 V.
– 10 – IEC 60335-2-81:2015 © IEC 2015
5.5 Addition:
If the appliance is provided with a detachable cover, the tests are carried out with or without
this cover, whichever is more unfavourable.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Appliances shall be class II or class III.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Washable appliances shall be marked with symbol ISO 7000-3114 (2012-04) and with symbol
ISO 7000-3124 (2012-04).
7.6 Addition:
[symbol ISO 7000-3114 (2012-04)] Do not dry clean

[symbol ISO 7000-3124 (2012-04)] Do not bleach

7.12 Addition:
The instructions shall state the substance of the following:
– the appliance is not to be used if there are signs of damage;
– the appliance is not to be used for warming animals;
– details regarding laundering or cleaning.
The instructions for foot warmers shall state that outdoor shoes must be removed before
use.
The instructions for heating mats shall state that the appliance has to be repaired or replaced
if the cover is worn. They shall explain how such wear can be observed.
The instructions for foot warmers intended to be used after preheating without supply and
incorporating an appliance inlet shall state that the cord set must be disconnected from the
supply after preheating.
If symbol ISO 7000-3114 (2012-04) and symbol ISO 7000-3124 (2012-04) are used, their
meaning shall be explained.
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable except as follows.
10.101 The power input of appliances incorporating heating elements with PTC
characteristics shall significantly decrease with an increase in temperature.
Compliance is checked by the following test.
The appliance is supplied at rated voltage and operated under normal operation. The power
input shall have decreased by at least 50 % from the initial value when steady conditions are
established, any control operating during this period being short-circuited.
11 Heating
This clause of Part 1 is applicable except as follows:
11.2 Modification:
Appliances are placed as near as possible to one wall of the test corner and away from the
other wall.
11.3 Addition:
Thermocouples attached to the small blackened disks are also used for measuring the
temperature rise of the surface of the appliance.
11.7 Replacement:
Appliances are operated until steady conditions are established.
11.8 Modification:
When polyvinyl chloride is used for insulating heating elements, the temperature rise of the
insulation shall not exceed 80 K.
Addition:
The temperature rise of surfaces likely to be in contact with the user's feet shall not exceed
40 K.
– 12 – IEC 60335-2-81:2015 © IEC 2015
12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable except as follows.
13.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heating mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.1.1 Addition:
Appliances are subjected to the test of IEC 60529 as described in Subclause 14.2.1.
However, cord sets, switches and controls in the flexible cord are not subjected to the tests.
16 Leakage current and electric strength
This clause of Part 1 is applicable except as follows.
16.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heated mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
18 Endurance
This clause of Part 1 is not applicable.

19 Abnormal operation
This clause of Part 1 is applicable except as follows.
19.2 Addition:
The appliance is covered partially or completely, whichever is more unfavourable, with a
sheet of open-cell polyether approximately 36 mm thick, having the following properties:
+2
– cell count 18 per cm;
+10
– specific mass 30 kg/m + %;
– hardness 120 N to 170 N at 40 % impression, measured according to ISO 2439.
If the foot warmer has a flexible part that covers the user's legs, this part is folded onto the
foot part before covering.
A plywood board, having dimensions approximately 500 mm × 500 mm × 20 mm, is placed on
top of the polyether sheet covering foot warmers.
19.4 Modification:
Heating mats are tested without being covered by the polystyrene block.
19.13 Addition:
The temperature rise of the insulation of heating elements shall not exceed 145 K.
20 Stability and mechanical hazards
This clause of Part 1 is applicable.
21 Mechanical strength
This clause of Part 1 is applicable except as follows.
21.1 Addition:
Foot warmers are also subjected to the test of 21.101.
21.2 Addition:
This requirement is not applicable to textiles and similar materials forming the enclosure.
21.101 A plywood board, having dimensions approximately 300 mm × 150 mm × 20 mm with
rounded edges, is placed in the leg section of the foot warmer as shown in Figure 101. A
load of 30 kg is placed on the board, which is allowed to drop freely from a height of 200 mm
above the base, so that the leg section is flexed and the appliance is compressed between
the board and the supporting surface. The total mass of the board, its movable support and
the load is 30 kg. If the foot warmer does not have a leg section, the board is allowed to fall
onto the top surface.
The test is carried out 1 000 times at a rate of six times per minute.

– 14 – IEC 60335-2-81:2015 © IEC 2015
The test shall not result in
– damage to the enclosure or displacement of heating elements to such an extent that
compliance with the standard is impaired;
– open-circuiting of heating elements or controls;
– breakage of more than 10 % of the strands of internal wiring;
– failure of constructional stitching, or breakage of glued or welded joints, to such an extent
that compliance with the standard is impaired.
NOTE An example of damage to the enclosure that could impair compliance with the standard is a tear in the
enclosure. Small holes in textiles that are not part of electrical insulation or do not provide protection against
moisture are ignored.
21.102 The insulation of heating elements and internal wiring shall retain adequate flexibility
and insulating characteristics throughout the life of the appliance.
Compliance is checked by the tests of 21.102.1 and by the tests of 21.102.2 and 21.102.3
when the insulation exceeds
– a temperature rise of 50 K during the test of Clause 11,
or
– a temperature rise of 110 K during the tests of Clause 19.
The tests are carried out on separate samples of heating element or internal wiring.
For the test of 21.102.1, one sample measuring approximately 4 m in length is required. For
the tests of 21.102.2, at least 12 samples are required, each having a length of 300 mm. For
the test of 21.102.3, 12 samples are required, each having a length of 300 mm.
21.102.1 The sample of heating element or internal wiring is attached to the equipment
shown in Figure 102. This equipment has a carrier with two pulleys, each having a groove
with a radius of 4 mm, the diameter at the base of the groove being 25 mm. The pulleys are
arranged so that the sample is horizontal where it passes between them.
NOTE 1 For samples not having a circular cross-section, the form of the groove in the pulley is suitably modified.
The sample is stretched over the pulleys, each end being loaded with a mass of 0,25 kg. If
necessary, the mass at each end is increased in steps of 0,1 kg in order to ensure that the
wires leaving the pulleys are parallel to each other. Restraining clamps are positioned so that
the pull is always applied by the mass in the opposite direction from which the carrier is
moving.
The carrier moves over a distance of 1 m with a constant speed of approximately 0,33 m/s for
25 000 cycles.
NOTE 2 A cycle is two movements, one in each direction.
The sample shall not break during the test.
NOTE 3 A monitoring current not exceeding 50 mA can be passed through the sample during the test.
For heating elements with PTC characteristics, the power input is measured before and
after the test. The measurement is made with the heating element suspended vertically in
free air and supplied at the rated voltage of the appliance. Both measurements are carried
out at the same ambient temperature and when the power input has stabilized. The power
input shall not increase during the test.
The sample is then immersed in water containing approximately 1 % NaCl. A d.c. voltage of
approximately 500 V is applied between the conductor and the saline solution.

The insulation resistance is measured 1 min after immersion and shall be at least 1 MΩ.
21.102.2 The conductors are pulled out from 12 samples of heating element or internal
wiring. If this is not possible, the insulation is slit longitudinally, the conductor is removed and
the insulation allowed to close.
Six of the samples are conditioned by suspending them vertically so that they hang freely in a
heating cabinet at a temperature of 125 °C ± 2 °C for 336 h. The samples are removed from
the cabinet and allowed to cool down to room temperature. When the material has stabilized,
the length of the samples is measured and shall not be less than 90 % of the original length.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The 12 samples are placed in a tensile machine, in turn, so that the length between the
clamps is at least 50 mm. The machine is operated at a uniform speed of
500 mm/min ± 50 mm/min. The force and elongation at the instant of rupture are determined.
Results obtained from any sample that ruptured at a force differing from the average value by
more than 10 %, and from samples that ruptured within a distance of 15 mm from the clamp,
are disregarded. Additional samples are tested in order to obtain 12 valid results.
The elongation of each of the unconditioned samples shall not be less than 100 % and their
tensile strength shall not be less than 8,75 MPa.
The average value of both the elongation and tensile strength of the conditioned samples
shall be not less than 75 % of the average value determined for the unconditioned samples.
21.102.3 A 10 mm length of insulation is removed from each end of 12 samples of heating
element or internal wiring.
Six of the samples are wound in a close helix of six turns on a metal mandrel having a
diameter approximately equal to the external diameter of the samples. Together with the
remaining six samples, they are placed in a heating cabinet at a temperature of 125 °C ± 2 °C
for 336 h. The samples are removed from the cabinet and allowed to cool down to room
temperature.
When the material has stabilized, the other six samples are also wound on the mandrel in the
same way.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The mandrel is immersed for 1 h in water containing approximately 1 % NaCl. The samples
are then subjected to a test voltage of 1 000 V for class II appliances and 500 V for class III
appliances. The voltage is applied for 1 min between the conductors and the solution and
there shall be no breakdown.
The samples are unwound from the mandrel and inspection shall show that there are no
visible cracks.
21.103 Heating elements with PTC characteristics shall be resistant to crushing.

– 16 – IEC 60335-2-81:2015 © IEC 2015
Compliance is checked by the following test.
The flexible part is fully supported by a piece of plywood 20 mm thick and supplied as
specified in 11.4. When steady conditions are established, the temperature of the heating
element is measured. A block having dimensions of 100 mm × 300 mm and a mass of 80 kg
is applied for 5 min to the surface in the most unfavourable place. After removing the block,
the appliance is again operated until steady conditions are established and the temperature of
the heating element is measured. The temperature of the heating element where the block
has been applied shall not have increased by more than 10 K.
NOTE 1 The edges of the block in contact with the flexible part are rounded.
NOTE 2 The most unfavourable place to apply the block is usually at a loop in the element.
22 Construction
This clause of Part 1 is applicable except as follows.
22.101 Appliances shall be constructed so that heating elements and internal wiring are
retained in their intended position. No part of the heating element shall cross over another
part of the heating element.
Crossing of internal wiring shall be avoided as far as possible. When this is unavoidable, the
wiring shall be secured in order to prevent any relative movement.
Compliance is checked by inspection.
22.102 There shall be no significant change in the position of the heating elements if the
stitching retaining them in position is broken.
Compliance is checked by inspection after breaking the thread in the most unfavourable
place.
22.103 The insulation of heating elements and internal wiring, except in class III
appliances, shall be integral with the conductor.
Compliance is checked by inspection.
22.104 Heating mats shall be constructed so that exposure of insulation of heating element
and internal wiring shall be readily observed.
Compliance is checked by inspection after removing other materials such as carpet pile. The
colours of the insulation shall be different from the colours of the other materials.
22.105 The appliance inlet in foot warmers shall be positioned so that the connector is not
in contact with the floor.
Compliance is checked by inspection.
23 Internal wiring
This clause of Part 1 is applicable.

24 Components
This clause of Part 1 is applicable except as follows.
24.1.3 Modification:
Switches are tested for 6 000 cycles of operation.
24.1.4 Modification:
Thermostats are operated for 100 000 cycles of operation and self-resetting thermal cut-
outs for 10 000 cycles of operation.
24.1.5 Addition:
All parts of IEC 60320-1 are applicable except for those that make reference to the
connectors in the standard sheets of IEC 60320-1.
24.2 Modification:
Appliances may be fitted with switches and controls in flexible cords.
25 Supply connection and external flexible cords
This clause of Part 1 is applicable except as follows.
25.5 Addition:
Type Z attachment is allowed.
25.15 Modification:
The pull force is increased to 60 N.
26 Terminals for external conductors
This clause of Part 1 is applicable.
27 Provision for earthing
This clause of Part 1 is applicable.
28 Screws and connections
This clause of Part 1 is applicable.
29 Clearances, creepage distances and solid insulation
This clause of Part 1 is applicable except as follows.
29.1.3 Addition:
– 18 – IEC 60335-2-81:2015 © IEC 2015
The clearance between the engagement face and contact tubes of appliance couplers used
for supplying the flexible part shall be at least 3,5 mm.
29.2 Addition:
The microenvironment is pollution degree 3 unless the insulation is enclosed or located so
that it is unlikely to be exposed to pollution during normal use of the appliance.
29.3 Addition:
The requirement does not apply to the part containing heating elements.
30 Resistance to heat and fire
This clause of Part 1 is applicable except as follows.
30.1 Addition:
The test is not applied to enclosures that are likely to be flexed in normal use.
Modification:
Parts of resilient plastic material are subjected to the pressure test of 24.1.3 of
IEC 60320-1:2001 instead of the ball pressure test of IEC 60695-10-2.
NOTE 101 An example of a part of resilient plastic material is a connection block.
30.2 Modification:
The test is not carried out on textiles and similar materials forming the enclosure of foot
warmers.
30.2.2 Not applicable.
30.2.3.2 Addition:
The needle-flame test is not carried out on textile materials.
30.101 Textiles and similar materials forming the enclosure of foot warmers shall be
adequately resistant to ignition.
Compliance is checked by a spark ignition test that is carried out on six samples of the
material. Each sample has dimensions approximately 200 mm × 100 mm. Any pieces of
heating element and trimming are removed from the samples.
The test fixture, as shown in Figure 103, has two brass electrodes 3 mm in diameter that are
supported by brass pillars mounted on a base plate of insulating material so that their axes
are aligned. The base plate also supports a platform of insulating material, having dimensions
of 100 mm × 100 mm, and located centrally between the brass p
...

IEC 60335-2-81 ®
Edition 3.1 2017-10
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-81: Exigences particulières pour les chancelières et les carpettes
chauffantes électriques
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IEC 60335-2-81 ®
Edition 3.1 2017-10
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats
Appareils électrodomestiques et analogues – Sécurité –
Partie 2-81: Exigences particulières pour les chancelières et les carpettes
chauffantes électriques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.120, 97.100.10 ISBN 978-2-8322-7174-2

IEC 60335-2-81 ®
Edition 3.1 2017-10
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Household and similar electrical appliances – Safety –
Part 2-81: Particular requirements for foot warmers and heating mats

Appareils électrodomestiques et analogues – Sécurité –
Partie 2-81: Exigences particulières pour les chancelières et les carpettes
chauffantes électriques
– 2 – IEC 60335-2-81:2015+AMD1:2017 CSV
© IEC 2017
CONTENTS
FOREWORD . 3
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 General requirement . 8
5 General conditions for the tests . 8
6 Classification . 9
7 Marking and instructions . 9
8 Protection against access to live parts . 10
9 Starting of motor-operated appliances . 10
10 Power input and current . 10
11 Heating . 10
12 Void . 11
13 Leakage current and electric strength at operating temperature . 11
14 Transient overvoltages . 11
15 Moisture resistance . 11
16 Leakage current and electric strength . 11
17 Overload protection of transformers and associated circuits . 11
18 Endurance . 11
19 Abnormal operation . 12
20 Stability and mechanical hazards . 12
21 Mechanical strength . 12
22 Construction . 15
23 Internal wiring . 15
24 Components . 16
25 Supply connection and external flexible cords . 16
26 Terminals for external conductors . 16
27 Provision for earthing . 16
28 Screws and connections . 16
29 Clearances, creepage distances and solid insulation . 17
30 Resistance to heat and fire . 17
31 Resistance to rusting . 19
32 Radiation, toxicity and similar hazards . 19
Annexes . 23
Bibliography . 24

Figure 101 – Equipment for the flexing test for foot warmers . 19
Figure 102 – Equipment for flexing heating elements and internal wiring . 20
Figure 103 – Equipment for the spark ignition test . 21
Figure 104 – Details of the mask . 22

© IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
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, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for 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
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60335-2-81 edition 3.1 contains the third edition (2015-04) [documents 61/4841/FDIS
and 61/4896/RVD] and its amendment 1 (2017-10) [documents 61/5292/CDV and
61/5378A/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
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© IEC 2017
This part of International Standard IEC 60335 has been prepared by IEC technical committee
61: Safety of household and similar electrical appliances.
This third edition constitutes a technical revision.
The principal changes in this edition as compared with the second edition of IEC 60335-2-81
are as follows (minor changes are not listed):
• Requirements for washable appliances (5.3, 7.1, 7.6, 7.12);
• Requirements for controls in flexible cords (15.1.1, 24.2);
• Requirements for appliance inlets (22.105, 24.1.5, 29.1.3).
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This part 2 is to be used in conjunction with the latest edition of IEC 60335-1 and its
amendments. It was established on the basis of the fifth edition (2010) of that standard.
NOTE 1 When “Part 1” is mentioned in this standard, it refers to IEC 60335-1.
This part 2 supplements or modifies the corresponding clauses in IEC 60335-1, so as to
convert that publication into the IEC standard: Safety requirements for foot warmers and
heating mats.
When a particular subclause of Part 1 is not mentioned in this part 2, that subclause applies
as far as is reasonable. When this standard states “addition”, “modification” or “replacement”,
the relevant text in Part 1 is to be adapted accordingly.
NOTE 2 The following numbering system is used:
– subclauses, tables and figures that are numbered starting from 101 are additional to those in Part 1;
– unless notes are in a new subclause or involve notes in Part 1, they are numbered starting from 101, including
those in a replaced clause or subclause;
– additional annexes are lettered AA, BB, etc.
NOTE 3 The following print types are used:
– requirements: in roman type;
– test specifications: in italic type;
– notes: in small roman type.
Words in bold in the text are defined in Clause 3. When a definition concerns an adjective, the adjective and the
associated noun are also in bold.
The committee has decided that the contents of this document and its amendment will remain
unchanged until the stability date indicated on the IEC website under 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.
© IEC 2017
NOTE 4 The attention of National Committees is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests.
It is the recommendation of the committee that the content of this publication be adopted for implementation
nationally not earlier than 12 months or later than 36 months from the date of publication.
A list of all parts of the IEC 60335 series, under the general title: Household and similar electrical appliances –
Safety, can be found on the IEC website.
The following differences exist in the countries indicated below.
– 3.1.9: Normal operation is different (USA)
– 6.1: Class 0 appliances are allowed if their rated voltage does not exceed 150 V (Japan)
– 6.1: Class 0 and class I appliances are allowed (USA)
– 7.6: Symbols not permitted to replace required text (USA)
– 11.8: Temperature limit is different (USA)
– 13.2: Method and limit is different (USA)
– 19.2: The test is different (USA)
– 21.101: The test is different (USA)
– 22.101: The tests are different (USA)

IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

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© IEC 2017
INTRODUCTION
It has been assumed in the drafting of this International Standard that the execution of its
provisions is entrusted to appropriately qualified and experienced persons.
This standard recognizes the internationally accepted level of protection against hazards such
as electrical, mechanical, thermal, fire and radiation of appliances when operated as in
normal use taking into account the manufacturer's instructions. It also covers abnormal
situations that can be expected in practice and takes into account the way in which
electromagnetic phenomena can affect the safe operation of appliances.
This standard takes into account the requirements of IEC 60364 as far as possible so that
there is compatibility with the wiring rules when the appliance is connected to the supply
mains. However, national wiring rules may differ.
If an appliance within the scope of this standard also incorporates functions that are covered
by another part 2 of IEC 60335, the relevant part 2 is applied to each function separately, as
far as is reasonable. If applicable, the influence of one function on the other is taken into
account.
When a part 2 standard does not include additional requirements to cover hazards dealt with
in Part 1, Part 1 applies.
NOTE 1 This means that the technical committees responsible for the part 2 standards have determined that it is
not necessary to specify particular requirements for the appliance in question over and above the general
requirements.
This standard is a product family standard dealing with the safety of appliances and takes
precedence over horizontal and generic standards covering the same subject.
NOTE 2 Horizontal and generic standards covering a hazard are not applicable since they have been taken into
consideration when developing the general and particular requirements for the IEC 60335 series of standards. For
example, in the case of temperature requirements for surfaces on many appliances, generic standards, such as
ISO 13732-1 for hot surfaces, are not applicable in addition to Part 1 or part 2 standards.
An appliance that complies with the text of this standard will not necessarily be considered to
comply with the safety principles of the standard if, when examined and tested, it is found to
have other features that impair the level of safety covered by these requirements.
An appliance employing materials or having forms of construction differing from those detailed
in the requirements of this standard may be examined and tested according to the intent of
the requirements and, if found to be substantially equivalent, may be considered to comply
with the standard.
© IEC 2017
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
SAFETY –
Part 2-81: Particular requirements for
foot warmers and heating mats
1 Scope
This clause of Part 1 is replaced by the following.
This International Standard deals with the safety of electric foot warmers and heating mats
for household and similar purposes, their rated voltage being not more than 250 V.
Appliances not intended for normal household use but which nevertheless may be a source of
danger to the public, such as appliances intended to be used by laymen in shops, in light
industry and on farms, are within the scope of this standard.
As far as is practicable, this standard deals with the common hazards presented by
appliances that are encountered by all persons in and around the home. However, in general,
it does not take into account
– persons (including children) whose
• physical, sensory or mental capabilities; or
• lack of experience and knowledge
prevents them from using the appliance safely without supervision or instruction;
– children playing with the appliance.
NOTE 101 Attention is drawn to the fact that
– for appliances intended to be used in vehicles or on board ships or aircraft, additional requirements may be
necessary;
– in many countries additional requirements are specified by the national health authorities, the national
authorities responsible for the protection of labour, and similar authorities.
NOTE 102 This standard does not apply to
– appliances specifically intended for use under medical supervision;
– electric blankets and pads (IEC 60335-2-17);
– electrically heated carpets (IEC 60335-2-106);
– electrical heating appliances for breeding and rearing animals (IEC 60335-2-71).
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 60320-1:2001, Appliance couplers for household and similar general purposes – Part 1:
General requirements
IEC 60320-1:2001/AMD1:2007
________________
There exists a consolidated edition 2.1 (2007) that includes the second edition and its Amendment 1.

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© IEC 2017
ISO 2439, Flexible cellular polymeric materials – Determination of hardness (indentation
technique)
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.1.9 Replacement:
normal operation
operation of the appliance under the following conditions:
Foot warmers are unfilled and placed on a horizontal surface.
Heating mats are placed on a horizontal surface and covered by a piece of expanded
polystyrene having dimensions approximately 300 mm × 150 mm × 50 mm.
3 3
NOTE 101 The density of the polystyrene is approximately 20 kg/m ± 5 kg/m .
3.101
foot warmer
appliance into which the user's feet are inserted in order to warm them
3.102
heating mat
appliance having an area not exceeding 0,5 m , on which the user's feet are placed in order
to warm them
3.103
heating element with PTC characteristics
heating element of the appliance consisting of a pair of conductors separated by conductive
material that has a rapid non-linear increase in resistance when the temperature is raised
through a particular range
4 General requirement
This clause of Part 1 is applicable.
5 General conditions for the tests
This clause of Part 1 is applicable except as follows.
5.2 Addition:
A 15 m length of heating element or internal wiring is required for the tests of 21.102.
Twelve samples of the enclosure material of foot warmers, each having dimensions
200 mm × 100 mm, are required for the test of 30.101.
5.3 Addition:
Washable appliances are laundered twice in accordance with the instructions before testing is
started.
The tests of Clauses 13, 15 and 16 are not carried out on Class III appliances having a rated
voltage not exceeding 24 V or on Class III constructions having a working voltage not
exceeding 24 V.
© IEC 2017
5.5 Addition:
If the appliance is provided with a detachable cover, the tests are carried out with or without
this cover, whichever is more unfavourable.
6 Classification
This clause of Part 1 is applicable except as follows.
6.1 Modification:
Appliances shall be class II or class III.
7 Marking and instructions
This clause of Part 1 is applicable except as follows.
7.1 Addition:
Washable appliances shall be marked with symbol ISO 7000-3114 (2012-04) and with symbol
ISO 7000-3124 (2012-04).
7.6 Addition:
[symbol ISO 7000-3114 (2012-04)] Do not dry clean

[symbol ISO 7000-3124 (2012-04)] Do not bleach

7.12 Addition:
The instructions shall state the substance of the following:
– the appliance is not to be used if there are signs of damage;
– the appliance is not to be used for warming animals;
– details regarding laundering or cleaning.
The instructions for foot warmers shall state that outdoor shoes must be removed before
use.
The instructions for heating mats shall state that the appliance has to be repaired or replaced
if the cover is worn. They shall explain how such wear can be observed.
The instructions for foot warmers intended to be used after preheating without supply and
incorporating an appliance inlet shall state that the cord set must be disconnected from the
supply after preheating.
If symbol ISO 7000-3114 (2012-04) and symbol ISO 7000-3124 (2012-04) are used, their
meaning shall be explained.
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© IEC 2017
8 Protection against access to live parts
This clause of Part 1 is applicable.
9 Starting of motor-operated appliances
This clause of Part 1 is not applicable.
10 Power input and current
This clause of Part 1 is applicable except as follows.
10.101 The power input of appliances incorporating heating elements with PTC
characteristics shall significantly decrease with an increase in temperature.
Compliance is checked by the following test.
The appliance is supplied at rated voltage and operated under normal operation. The power
input shall have decreased by at least 50 % from the initial value when steady conditions are
established, any control operating during this period being short-circuited.
11 Heating
This clause of Part 1 is applicable except as follows:
11.2 Modification:
Appliances are placed as near as possible to one wall of the test corner and away from the
other wall.
11.3 Addition:
Thermocouples attached to the small blackened disks are also used for measuring the
temperature rise of the surface of the appliance.
11.7 Replacement:
Appliances are operated until steady conditions are established.
11.8 Modification:
When polyvinyl chloride is used for insulating heating elements, the temperature rise of the
insulation shall not exceed 80 K.
Addition:
The temperature rise of surfaces likely to be in contact with the user's feet shall not exceed
40 K.
© IEC 2017
12 Void
13 Leakage current and electric strength at operating temperature
This clause of Part 1 is applicable except as follows.
13.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heating mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
14 Transient overvoltages
This clause of Part 1 is applicable.
15 Moisture resistance
This clause of Part 1 is applicable except as follows.
15.1.1 Addition:
Appliances are subjected to the test of IEC 60529 as described in Subclause 14.2.1.
However, cord sets, switches and controls in the flexible cord are not subjected to the tests.
16 Leakage current and electric strength
This clause of Part 1 is applicable except as follows.
16.2 Modification:
When testing the top surface of heating mats, the dimensions of the metal foil are
300 mm × 150 mm.
NOTE 101 If the heated mat is reversible, each surface is tested in turn.
Addition:
Foot warmers are also tested with the inside surface completely covered with metal foil.
17 Overload protection of transformers and associated circuits
This clause of Part 1 is applicable.
18 Endurance
This clause of Part 1 is not applicable.

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© IEC 2017
19 Abnormal operation
This clause of Part 1 is applicable except as follows.
19.2 Addition:
The appliance is covered partially or completely, whichever is more unfavourable, with a
sheet of open-cell polyether approximately 36 mm thick, having the following properties:
+2
per cm;
– cell count 18
+10
– specific mass 30 kg/m + %;
– hardness 120 N to 170 N at 40 % impression, measured according to ISO 2439.
If the foot warmer has a flexible part that covers the user's legs, this part is folded onto the
foot part before covering.
A plywood board, having dimensions approximately 500 mm × 500 mm × 20 mm, is placed on
top of the polyether sheet covering foot warmers.
19.4 Modification:
Heating mats are tested without being covered by the polystyrene block.
19.13 Addition:
The temperature rise of the insulation of heating elements shall not exceed 145 K.
20 Stability and mechanical hazards
This clause of Part 1 is applicable.
21 Mechanical strength
This clause of Part 1 is applicable except as follows.
21.1 Addition:
Foot warmers are also subjected to the test of 21.101.
21.2 Addition:
This requirement is not applicable to textiles and similar materials forming the enclosure.
21.101 A plywood board, having dimensions approximately 300 mm × 150 mm × 20 mm with
rounded edges, is placed in the leg section of the foot warmer as shown in Figure 101. A
load of 30 kg is placed on the board, which is allowed to drop freely from a height of 200 mm
above the base, so that the leg section is flexed and the appliance is compressed between
the board and the supporting surface. The total mass of the board, its movable support and
the load is 30 kg. If the foot warmer does not have a leg section, the board is allowed to fall
onto the top surface.
The test is carried out 1 000 times at a rate of six times per minute.

© IEC 2017
The test shall not result in
– damage to the enclosure or displacement of heating elements to such an extent that
compliance with the standard is impaired;
– open-circuiting of heating elements or controls;
– breakage of more than 10 % of the strands of internal wiring;
– failure of constructional stitching, or breakage of glued or welded joints, to such an extent
that compliance with the standard is impaired.
NOTE An example of damage to the enclosure that could impair compliance with the standard is a tear in the
enclosure. Small holes in textiles that are not part of electrical insulation or do not provide protection against
moisture are ignored.
21.102 The insulation of heating elements and internal wiring shall retain adequate flexibility
and insulating characteristics throughout the life of the appliance.
Compliance is checked by the tests of 21.102.1 and by the tests of 21.102.2 and 21.102.3
when the insulation exceeds
– a temperature rise of 50 K during the test of Clause 11,
or
– a temperature rise of 110 K during the tests of Clause 19.
The tests are carried out on separate samples of heating element or internal wiring.
For the test of 21.102.1, one sample measuring approximately 4 m in length is required. For
the tests of 21.102.2, at least 12 samples are required, each having a length of 300 mm. For
the test of 21.102.3, 12 samples are required, each having a length of 300 mm.
21.102.1 The sample of heating element or internal wiring is attached to the equipment
shown in Figure 102. This equipment has a carrier with two pulleys, each having a groove
with a radius of 4 mm, the diameter at the base of the groove being 25 mm. The pulleys are
arranged so that the sample is horizontal where it passes between them.
NOTE 1 For samples not having a circular cross-section, the form of the groove in the pulley is suitably modified.
The sample is stretched over the pulleys, each end being loaded with a mass of 0,25 kg. If
necessary, the mass at each end is increased in steps of 0,1 kg in order to ensure that the
wires leaving the pulleys are parallel to each other. Restraining clamps are positioned so that
the pull is always applied by the mass in the opposite direction from which the carrier is
moving.
The carrier moves over a distance of 1 m with a constant speed of approximately 0,33 m/s for
25 000 cycles.
NOTE 2 A cycle is two movements, one in each direction.
The sample shall not break during the test.
NOTE 3 A monitoring current not exceeding 50 mA can be passed through the sample during the test.
For heating elements with PTC characteristics, the power input is measured before and
after the test. The measurement is made with the heating element suspended vertically in
free air and supplied at the rated voltage of the appliance. Both measurements are carried
out at the same ambient temperature and when the power input has stabilized. The power
input shall not increase during the test.
The sample is then immersed in water containing approximately 1 % NaCl. A d.c. voltage of
approximately 500 V is applied between the conductor and the saline solution.

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© IEC 2017
The insulation resistance is measured 1 min after immersion and shall be at least 1 MΩ.
21.102.2 The conductors are pulled out from 12 samples of heating element or internal
wiring. If this is not possible, the insulation is slit longitudinally, the conductor is removed and
the insulation allowed to close.
Six of the samples are conditioned by suspending them vertically so that they hang freely in a
heating cabinet at a temperature of 125 °C ± 2 °C for 336 h. The samples are removed from
the cabinet and allowed to cool down to room temperature. When the material has stabilized,
the length of the samples is measured and shall not be less than 90 % of the original length.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The 12 samples are placed in a tensile machine, in turn, so that the length between the
clamps is at least 50 mm. The machine is operated at a uniform speed of
500 mm/min ± 50 mm/min. The force and elongation at the instant of rupture are determined.
Results obtained from any sample that ruptured at a force differing from the average value by
more than 10 %, and from samples that ruptured within a distance of 15 mm from the clamp,
are disregarded. Additional samples are tested in order to obtain 12 valid results.
The elongation of each of the unconditioned samples shall not be less than 100 % and their
tensile strength shall not be less than 8,75 MPa.
The average value of both the elongation and tensile strength of the conditioned samples
shall be not less than 75 % of the average value determined for the unconditioned samples.
21.102.3 A 10 mm length of insulation is removed from each end of 12 samples of heating
element or internal wiring.
Six of the samples are wound in a close helix of six turns on a metal mandrel having a
diameter approximately equal to the external diameter of the samples. Together with the
remaining six samples, they are placed in a heating cabinet at a temperature of 125 °C ± 2 °C
for 336 h. The samples are removed from the cabinet and allowed to cool down to room
temperature.
When the material has stabilized, the other six samples are also wound on the mandrel in the
same way.
NOTE PVC material is considered to have stabilized by 16 h after removal from the cabinet.
The heating cabinet shall have forced air circulation in order to ensure that there is no
temperature gradient over the length of the samples.
The mandrel is immersed for 1 h in water containing approximately 1 % NaCl. The samples
are then subjected to a test voltage of 1 000 V for class II appliances and 500 V for class III
appliances. The voltage is applied for 1 min between the conductors and the solution and
there shall be no breakdown.
The samples are unwound from the mandrel and inspection shall show that there are no
visible cracks.
21.103 Heating elements with PTC characteristics shall be resistant to crushing.

© IEC 2017
Compliance is checked by the following test.
The flexible part is fully supported by a piece of plywood 20 mm thick and supplied as
specified in 11.4. When steady conditions are established, the temperature of the heating
element is measured. A block having dimensions of 100 mm × 300 mm and a mass of 80 kg
is applied for 5 min to the surface in the most unfavourable place. After removing the block,
the appliance is again operated until steady conditions are established and the temperature of
the heating element is measured. The temperature of the heating element where the block
has been applied shall not have increased by more than 10 K.
NOTE 1 The edges of the block in contact with the flexible part are rounded.
NOTE 2 The most unfavourable place to apply the block is usually at a loop in the element.
22 Construction
This clause of Part 1 is applicable except as follows.
22.101 Appliances shall be constructed so that heating elements and internal wiring are
retained in their intended position. No part of the heating element shall cross over another
part of the heating element.
Crossing of internal wiring shall be avoided as far as possible. When this is unavoidable, the
wiring shall be secured in order to prevent any relative movement.
Compliance is checked by inspection.
22.102 There shall be no significant change in the position of the heating elements if the
stitching retaining them in position is broken.
Compliance is checked by inspection after breaking the thread in the most unfavourable
place.
22.103 The insulation of heating elements and internal wiring, except in class III
appliances, shall be integral with the conductor.
Compliance is checked by inspection.
22.104 Heating mats shall be constructed so that exposure of insulation of heating element
and internal wiring shall be readily observed.
Compliance is checked by inspection after removing other materials such as carpet pile. The
colours of the insulation shall be different from the colours of the other materials.
22.105 The appliance inlet in foot warmers shall be positioned so that the connector is not
in contact with the floor.
Compliance is checked by inspection.
23 Internal wiring
This clause of Part 1 is applicable.

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© IEC 2017
24 Components
This clause of Part 1 is applicable except as follows.
24.1.3 Modification:
Switches are tested for 6 000 cycles of operation.
24.1.4 Modification:
Thermostats are operated for 100 000 cycles of operation and self-resetting thermal cut-
outs for 10 000 cycles of operation.
24.1.5 Addition:
All parts of IEC 60320-1 are applicable except for those that make reference to the
connectors in the standard sheets of IEC 60320-1.
24.2 Modification:
Appliances may be fitted with switches and controls in flexible cords.
25 Supply connection and external flexible cords
This clause of Part 1 is applicable except as follows.
25.5 Addition:
Type Z attachment is allowed.
25.14 Addition:
The test is applicable to appliances fitted with a non-detachable flexible cord. It also applies
to switches and controls fitted in the flexible cord.
25.15 Modification:
The pull force is increased to 60 N.
26 Terminals for external conductors
This clause of Part 1 is applicable.
27 Provision for earthing
This clause of Part 1 is applicable.
28 Screws and connections
This clause of Part 1 is applicable.

© IEC 2017
29 Clearances, creepage distances and solid insulation
This clause of Part 1 is applicable except as follows.
29.1.3 Addition:
The clearance between the engagement face and contact tubes of appliance couplers used
for supplying the flexible part shall be at least 3,5 mm.
29.2 Addition:
The microenvironment is pollution degree 3 unless the insulation is enclosed or located so
that it is unlikely to be exposed to pollution during normal use of the appliance.
29.3 Addition:
The requirement does not apply to the part containing heating elements.
30 Resistance to heat and fire
This clause of Part 1 is applicable except as follows.
30.1 Addition:
The test is not applied to enclosures that are likely to be flexed in normal use.
Modification:
Parts of resilient plastic material are subjected to the pressure test of 24.1.3 of
IEC 60320-1:2001 instead of the ball pressure test of IEC 60695-10-2.
NOTE 101 An example of a part of resilient plastic material is a connection block.
30.2 Modification:
The test is not carried out on textiles and similar materials forming the enclosure of foot
warmers.
30.2.2 Not applicable.
30.2.3.2 Addition:
The needle-flame test is not carried out on textile materials.
30.101 Textiles and similar materials forming the enclosure of foot warmers shall be
adequately resistant to ignition.
Compliance is checked
...