IEC 60721-2-7:2018

IEC 60721-2-7 ®
Edition 2.0 2018-03
INTERNATIONAL
STANDARD
Classification of environmental conditions –
Part 2-7: Environmental conditions appearing in nature – Fauna and flora

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 60721-2-7 ®
Edition 2.0 2018-03
INTERNATIONAL
STANDARD
Classification of environmental conditions –

Part 2-7: Environmental conditions appearing in nature – Fauna and flora

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 19.040 ISBN 978-2-8322-5483-7

– 2 – IEC 60721-2-7:2018 © IEC 2018
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General . 5
5 Occurrence of fauna and flora . 6
5.1 Fungi . 6
5.1.1 Background . 6
5.1.2 Growth and survival factors . 6
5.1.3 Habitat and geographical distribution . 7
5.1.4 Effects of fungi on materials . 8
5.2 Bacteria . 11
5.2.1 Background . 11
5.2.2 Growth and survival factors . 11
5.2.3 Habitat . 12
5.2.4 Effects of bacteria on materials. 12
5.3 Insects . 13
5.3.1 Background . 13
5.3.2 Habitat . 14
5.3.3 Effects of insects on materials . 14
5.4 Rodents . 14
5.4.1 Background . 14
5.4.2 Effects of rodents on materials . 14
5.5 Algae and marine organisms . 15
5.5.1 Algae . 15
5.5.2 Borers . 15
5.5.3 Fouling organisms . 15
Bibliography . 16

Figure 1 – Map of regions with different degrees of fungal corrosion . 8

Table 1 – List of fungus resistant materials . 9
Table 2 – List of potential fungus nutrient materials . 10

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CLASSIFICATION OF ENVIRONMENTAL CONDITIONS –

Part 2-7: Environmental conditions appearing in nature –
Fauna and flora
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.
International Standard IEC 60721-2-7 has been prepared by IEC technical committee 104:
Environmental conditions, classification and methods of test.
This second edition cancels and replaces the first edition published in 1987. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) This edition has been entirely rewritten.

– 4 – IEC 60721-2-7:2018 © IEC 2018
The text of this International Standard is based on the following documents:
CDV Report on voting
104/741/CDV 104/792/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

CLASSIFICATION OF ENVIRONMENTAL CONDITIONS –

Part 2-7: Environmental conditions appearing in nature –
Fauna and flora
1 Scope
This document addresses the occurrence of fauna and flora, including its main effects on
electrotechnical products. Exposure and damage from the effects of fauna and flora can occur
at almost any time in a product's life cycle. Moreover, there are many agents of attack with
various actions.
This document addresses the occurrence and damage arising from fauna and flora in all
locations a product can be stored, transported or used. Generally, fauna can be present and
cause damage to products in both the natural environments experienced in open-air locations
as well as in artificially created environments, such as in a warehouse or building. However,
flora will predominantly be present and cause damage to products only in open-air locations.
Fungus and bacteria can be present in both open-air locations as well as in warehouses or
buildings.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 General
The main attacking agents considered in this document are micro-organisms including fungi,
bacteria, as well as insects, rodents, algae and marine organisms. Hazards due to other
agents are considered to be of lesser importance and have been omitted. These include the
corrosive action of juices secreted by some plants, the mechanical action due to the growth of
the larger trees, which may be sufficiently great to destroy the foundations of a building or to
break cables, and the damage caused by animals such as monkeys and elephants. Birds in
flight can be a hazard to aircraft, and in the region of bird colonies, widespread droppings can
create corrosion problems. In addition, some agents which are mentioned have other modes
of action which have not been included; for example both rodents and insects are occasionally
responsible for chemical corrosion or soiling.
The frequency of occurrence of fauna and flora with a possibility of damaging products very
much depends on conditio
...