SIST EN IEC 60721-3-6:2025

SLOVENSKI STANDARD
01-november-2025
Nadomešča:
SIST EN 60721-3-6:2001
SIST EN 60721-3-6:2001/A2:2001
Klasifikacija okoljskih pogojev - 3. del: Razvrščanje skupin okoljskih parametrov
in njihove resnosti - Ladijsko okolje (IEC 60721-3-6:2025)
Classification of environmental conditions. part 3: Classification of groups of
environmental parameters and their severities - Ship environment (IEC 60721-3-6:2025)
Klassifizierung von Umgebungsbedingungen - Teil 3-6: Klassen von Einflussgrößen und
deren Grenzwerte - Ausrüstungen auf Schiffen (IEC 60721-3-6:2025)
Classification des conditions d'environnement - Partie 3: Classification des groupements
des agents d'environnement et de leurs sévérités - Environnement des navires (IEC
60721-3-6:2025)
Ta slovenski standard je istoveten z: EN IEC 60721-3-6:2025
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60721-3-6

NORME EUROPÉENNE
EUROPÄISCHE NORM September 2025
ICS 19.040 Supersedes EN 60721-3-6:1993; EN 60721-3-
6:1993/A2:1997
English Version
Classification of environmental conditions - Part 3-6:
Classification of groups of environmental parameters and their
severities - Ship environments
(IEC 60721-3-6:2025)
Classification des conditions d'environnement - Partie 3-6: Klassifizierung von Umgebungsbedingungen - Teil 3-6:
Classification des groupements des agents Klassen von Einflussgrößen und deren Grenzwerte -
d'environnement et de leurs sévérités - Environnement des Ausrüstungen auf Schiffen
navires (IEC 60721-3-6:2025)
(IEC 60721-3-6:2025)
This European Standard was approved by CENELEC on 2025-08-06. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60721-3-6:2025 E

European foreword
The text of document 104/1094/FDIS, future edition 2 of IEC 60721-3-6, prepared by TC 104
"Environmental conditions, classification and methods of test" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN IEC 60721-3-6:2025.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-09-30
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-09-30
document have to be withdrawn
This document supersedes EN 60721-3-6:1993 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60721-3-6:2025 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60721-2 series NOTE Approved as EN 60721-2 series
IEC 60721-3 series NOTE Approved as EN IEC 60721-3 series
IEC 60721-3-0 NOTE Approved as EN IEC 60721-3-0
IEC 60721-3-2 NOTE Approved as EN IEC 60721-3-2
IEC 60721-3-6:1987 NOTE Approved as EN 60721-3-6:1993 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60721-1 - Classification of environmental conditions - EN 60721-1 -
Part 1: Environmental parameters and their
severities
IEC 60721-3-6 ®
Edition 2.0 2025-07
INTERNATIONAL
STANDARD
Classification of environmental conditions -
Part 3-6: Classification of groups of environmental parameters and their
severities – Ship environments
ICS 19.040  ISBN 978-2-8327-0513-1

IEC 60721-3-6:2025-07(en)
IEC 60721-3-6:2025 © IEC 2025
CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 General . 5
5 Classification of groups of environmental parameters and their severities . 6
5.1 General . 6
5.2 Climatic conditions (K) . 6
5.3 Biological conditions (B) . 10
5.4 Chemically active substances (C) . 10
5.5 Mechanically active substances (S) . 11
5.6 Mechanical conditions (M) . 12
Bibliography . 15

Figure 1 – Stationary vibration, sinusoidal . 14
Figure 2 – Non-stationary shock conditions . 14

Table 1 – Classification of climatic conditions . 8
Table 2 – Classification of biological conditions . 10
Table 3 – Classification of chemically active substances. 11
Table 4 – Classification of mechanically active substances . 12
Table 5 – Classification of mechanical conditions . 12

IEC 60721-3-6:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Classification of environmental conditions -
Part 3-6: Classification of groups of environmental
parameters and their severities - Ship environments

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60721-3-6 has been prepared by IEC technical committee 104: Environmental conditions,
classification and methods of test. It is an International Standard.
This second edition cancels and replaces the first edition, published in 1987, and constitutes a
technical revision.
This edition includes the following significant changes with respect to the previous edition:
a) most classes have been replaced by completely new classes based on the use of new
information obtained from referenced Technical Reports;
b) Table 1 through to Table 5 have been updated;
c) the content of Annex A and Annex B has either been incorporated into main body text or
deleted.
IEC 60721-3-6:2025 © IEC 2025
The text of this International Standard is based on the following documents:
Draft Report on voting
104/1094/FDIS 104/1113/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60721 series, published under the general title Classification of
environmental conditions, can be found on the IEC website.
The committee has decided that the contents of this document 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, or
• revised.
IEC 60721-3-6:2025 © IEC 2025
1 Scope
This part of IEC 60721 classifies the groups of environmental parameters and their severities
to which a product is subjected when installed aboard a ship.
Ships where electrotechnical products may be permanently or temporarily installed include
• ships propelled by mechanical means, including mobile offshore units, and
• ships not propelled by mechanical means, including sailing boats and life rafts.
The classes defined apply to all sizes of ship from pleasure craft to trawlers, ferry boats,
icebreakers, cargo ships including tankers.
The areas in which ships normally navigate are
• inland waterways (canals, rivers, lakes etc.),
• coastal waters, and
• oceans.
Areas where ships navigate in ice are also included.
The environmental conditions specified in this document are those that the product can be
exposed to whilst permanently or temporarily installed for the running, handling and safety of
the ship. The environmental conditions can also be used for other products, installed in a similar
way at similar locations.
Accidental incidents are not included but it can be important to take their occurrence into
account for products vital to the safety of the ship. The classification also does not cover the
effects of water pressure on submerged products.
Classification of storage and transportation environmental conditions are given in other
subparts of the IEC 60721-3 series.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60721-1, Classification of environmental conditions – Part 1: Environmental parameters
and their severities
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60721-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
IEC 60721-3-6:2025 © IEC 2025
3.1
weatherprotected
protected from the influences of meteorological conditions
3.2
non-weatherprotected
not protected from the influences of meteorological conditions
4 General
A product can be subjected to a range of environmental conditions during its lifetime. These
conditions have been separated into classes described in IEC 60721-3-0. The classes given
may be used for defining the maximum short-term environmental stresses on a product.
However, they do not provide information regarding the long-term or total lifetime environmental
stresses a product can experience. This means that no reliability or lifetime assessment is
possible based on these classes alone. Refer to the IEC 60721-2 series and applicable
technical reports (IEC TR 62130 and IEC TR 62131-8) for further information on actual
environmental conditions.
A product can be simultaneously exposed to a number of environmental parameters. For
example, solar radiation and temperature, temperature and humidity, as well as vibration and
temperature change. Combinations of the environmental parameters given can increase the
stress effect on a product. Therefore, combined conditions should be considered in the design
and evaluation of a product.
Products should be designed to survive and operate in different environments. Basically, they
will be affected by environmental influences in two ways:
• by the effects of short-term extreme environmental conditions which can directly cause
malfunction or destroy the product;
• by the effect of long-term subjection to non-extreme environmental stresses which can
slowly degrade the product and finally cause malfunction or destruction of the product.
Short-term extreme environmental conditions can occur at any time in a product's life. A product
can be unaffected by an extreme condition when it is new but fail when it is subjected to the
same condition after being used for a long period of time due to the effect of ageing. The order
in which the environmental conditions are applied can affect the results of an evaluation.
It is important for the product specification, when referring to a certain class in the
IEC 60721-3 series, to define whether the product is required to be capable of operating or only
to survive without permanent damage when being exposed to the conditions described by the
class.
The environmental classes may be used as a basis for the selection of design and test severities
with respect to the consequence of failure. Information contained in the IEC 60721-3 series may
be used as a means to help establish expected requirements for use, storage, transportation,
etc., and in the development of relevant specifications. The s
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