SIST EN IEC 60721-3-3:2019/A1:2026
(Amendment)Amendment 1 - Classification of environmental conditions - Part 3-3: Classification of groups of environmental parameters and their severities - Stationary use at weatherprotected locations (IEC 60721-3-3:2019/AMD1:2026)
- Status
- Published
- Public Enquiry End Date
- 22-May-2025
- Publication Date
- 28-Oct-2026
- Technical Committee
- I09 - Imaginarni 09
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 28-Oct-2026
- Due Date
- 02-Jan-2027
- Completion Date
- 29-Oct-2026
SIST EN IEC 60721-3-3:2019/A1:2026 is an IEC amendment published by SIST for the classification of environmental conditions for stationary use at weatherprotected locations. It updates how locations are classified for chemically active substances and mechanical conditions, so designers and test engineers can match equipment to the environment it will face.
What does SIST EN IEC 60721-3-3:2019/A1:2026 specify?
SIST EN IEC 60721-3-3:2019/A1:2026 amends IEC 60721-3-3:2019 for stationary use at weatherprotected locations. The amendment focuses on two environmental groups - chemically active substances and mechanical conditions - and replaces the related text, table, and figures in the base document.
The document is organized as targeted replacements rather than a full rewrite:
- subclause 5.5 on chemically active substances
- subclause 5.7 on mechanical conditions
- Table 5 and Figures 1, 2 and 3
- informative Annex C on classification of chemically active substances
What are the key requirements of SIST EN IEC 60721-3-3:2019/A1:2026?
The amendment gives practical classification rules for the environment around equipment installed in sheltered, stationary locations. In practice, users select the severities that match the site, then use those classes in product specification, design, and qualification.
Chemically active substances
Subclause 5.5 says contamination of the atmosphere can come from industrial emissions, vehicle exhaust, heating systems, sea salt, and road salt aerosols. It also states that these substances can affect both function and materials, so the chosen class should reflect the real exposure at the site.
For chemical contamination, the amendment allows two routes: classification based on ISO 9223 or the classification in Annex C. The document says the two approaches have different backgrounds, so the user has to choose the one that fits the application.
Mechanical conditions
Subclause 5.7 classifies mechanical conditions by vibration and shock. Table 5 and Figures 1 to 3 define five classes, from 3M10 through 3M14, ranging from insignificant vibration and shock to extremely high levels.
The practical meaning is straightforward: 3M10 suits very quiet locations, while 3M11 to 3M14 cover increasing exposure near air conditioning, machines, conveyors, heavy machinery, and power hammers. The amendment also notes that rotating machinery often produces complex sinusoidal vibration, while higher-frequency random vibration may be more relevant for electronics and small mechanisms.
Vibration and shock description
Table 5 separates three cases:
- stationary vibration, sinusoidal
- stationary vibration, random
- non-stationary vibration including shock
The figures provide the severity curves used for those cases. That matters because the same installation may need a different description depending on whether the dominant excitation is low-frequency rotating machinery, higher-frequency random vibration, or shock events.
Combined and alternative conditions
The text notes that shock can occur at the same time as stationary vibration. It also points users to Annex B for the definition of seismic environment, which is useful when the installation has earth-motion exposure in addition to local vibration.
Chemically active substances in Annex C
Annex C adds a detailed classification for chemically active substances. It explains that the values come from survey experience, that maximum values reflect short-term peaks, and that mean values represent longer-term exposure.
For classes 3C1 and 3C2, the severities are intended as combined requirements for all listed contaminants. For 3C3 and 3C4, the document allows selection of only the relevant single parameters to avoid over-design, while unspecified parameters default to 3C2 severities.
What terms does SIST EN IEC 60721-3-3:2019/A1:2026 define?
- Chemically active substances (C) - atmospheric contaminants that may attack materials or affect equipment function, such as sea salts, sulphur dioxide, or ozone.
- Mechanical conditions (M) - the vibration and shock environment at the installation location.
- Stationary vibration, sinusoidal - a vibration case used when the excitation is mainly regular and low-frequency, often linked to rotating machinery.
- Stationary vibration, random - a vibration case used when higher-frequency, non-regular vibration is expected.
- Non-stationary vibration including shock - transient excitation that can occur together with stationary vibration.
- 3C1R / 3C1L - refined chemical environment classes for controlled atmospheres, including clean room and continuously controlled conditions.
- 3M10 to 3M14 - mechanical severity classes from insignificant to extremely high vibration and shock.
Who uses SIST EN IEC 60721-3-3:2019/A1:2026?
This amendment is used by equipment designers, environmental test engineers, quality managers, and buyers who need to specify the environment for products installed at weatherprotected stationary locations. It is relevant for industrial equipment, electronics, and small mechanisms where vibration, shock, and atmospheric contamination affect reliability and material choice.
It is also useful for suppliers and purchasers writing environmental specifications, comparing site conditions, or deciding which tests and design margins are appropriate for a product.
What changed in SIST EN IEC 60721-3-3:2019/A1:2026 from the previous edition?
SIST EN IEC 60721-3-3:2019/A1:2026 is Amendment 1 to IEC 60721-3-3:2019. It replaces subclauses 5.5 and 5.7, deletes the former Table 5 and figures, and adds Annex C with the updated chemical classification guidance and table.
Which standards are used with SIST EN IEC 60721-3-3:2019/A1:2026?
- ISO 9223 - provides one of the two allowed ways to categorize chemically active substances.
- IEC 60721-3-3:2019 - the base part that this amendment updates for stationary use at weatherprotected locations.
What does the SIST EN IEC 60721-3-3:2019/A1:2026 document contain?
The document contains replacement text for chemical and mechanical environmental classification, a revised Table 5 for vibration and shock classes, and Figures 1 to 3 showing the related severity descriptions. It also adds informative Annex C with Table C.1 for chemically active substances, including classes, maximum and mean values, and notes on how to apply them in practice.
The content is written for environmental specification and qualification work, not for general description. In practical use, it helps users translate a site description into environmental classes that can be applied in design, testing, and product documentation.
Relations
- Effective Date
- 27-Oct-2026
- Effective Date
- 27-Oct-2026
- Effective Date
- 27-Oct-2026
- Effective Date
- 27-Oct-2026
- Effective Date
- 27-Oct-2026
- Effective Date
- 01-Dec-2026
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Frequently Asked Questions
SIST EN IEC 60721-3-3:2019/A1:2026 is a amendment published by the Slovenian Institute for Standardization (SIST). Its full title is "Amendment 1 - Classification of environmental conditions - Part 3-3: Classification of groups of environmental parameters and their severities - Stationary use at weatherprotected locations (IEC 60721-3-3:2019/AMD1:2026)". This standard covers: Amendment 1 - Classification of environmental conditions - Part 3-3: Classification of groups of environmental parameters and their severities - Stationary use at weatherprotected locations (IEC 60721-3-3:2019/AMD1:2026)
Amendment 1 - Classification of environmental conditions - Part 3-3: Classification of groups of environmental parameters and their severities - Stationary use at weatherprotected locations (IEC 60721-3-3:2019/AMD1:2026)
SIST EN IEC 60721-3-3:2019/A1:2026 is classified under the following ICS (International Classification for Standards) categories: 19.040 - Environmental testing. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN IEC 60721-3-3:2019/A1:2026 has the following relationships with other standards: It is inter standard links to SIST EN IEC 61514:2026, SIST EN IEC 61514-2:2026, SIST EN 60770-3:2014, SIST EN 50617-1:2015, SIST EN IEC 61987-1:2025, SIST EN IEC 60721-3-3:2019. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN IEC 60721-3-3:2019/A1:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2026
Klasifikacija okoljskih pogojev - 3-3. del: Klasifikacija skupin okoljskih parametrov
in njihove resnosti - Stacionarna uporaba na lokacijah, zaščitenih pred
vremenskimi vplivi - Dopolnilo A1 (IEC 60721-3-3:2019/AMD1:2026)
Amendment 1 - Classification of environmental conditions - Part 3-3: Classification of
groups of environmental parameters and their severities - Stationary use at
weatherprotected locations (IEC 60721-3-3:2019/AMD1:2026)
Klassifizierung von Umgebungsbedingungen - Teil 3-3: Klassen von Einflussgrößen und
deren Grenzwerte – Ortsfester Einsatz, wettergeschützt (IEC 60721-3-
3:2019/AMD1:2026)
Classification des conditions d'environnement - Partie 3-3: Classification des
groupements des agents d'environnement et de leurs sévérités - Utilisation à poste fixe,
protégé contre les intempéries (IEC 60721-3-3:2019/AMD1:2026)
Ta slovenski standard je istoveten z: EN IEC 60721-3-3:2019/A1:2026
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 60721-3-3:2019/A1
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2026
ICS 19.040
English Version
Classification of environmental conditions - Part 3-3:
Classification of groups of environmental parameters and their
severities - Stationary use at weatherprotected locations
(IEC 60721-3-3:2019/AMD1:2026)
Classification des conditions d'environnement - Partie 3-3: Klassifizierung von Umgebungsbedingungen - Teil 3-3:
Classification des groupements des agents Klassen von Einflussgrößen und deren Grenzwerte -
d'environnement et de leurs sévérités - Utilisation à poste Ortsfester Einsatz, wettergeschützt
fixe, protégé contre les intempéries (IEC 60721-3-3:2019/AMD1:2026)
(IEC 60721-3-3:2019/AMD1:2026)
This amendment A1 modifies the European Standard EN IEC 60721-3-3:2019; it was approved by CENELEC on 2026-10-20. CENELEC
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment 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 amendment 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
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60721-3-3:2019/A1:2026 E
European foreword
The text of document 104/1188/FDIS, future edition 3 of IEC 60721-3-3/AMD1, 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 60721-3-3:2019/A1:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-10-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-10-31
document have to be withdrawn
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 60721-3-3:2019/AMD1:2026 was approved by CENELEC
as a European Standard without any modification.
IEC 60721-3-3 ®
Edition 3.0 2026-09
INTERNATIONAL
STANDARD
AMENDMENT 1
Classification of environmental conditions -
Part 3-3: Classification of groups of environmental parameters and their
severities - Stationary use at weatherprotected locations
ICS 19.040 ISBN 978-2-8327-1480-5
IEC 60721-3-3:2019-05/AMD1:2026-09(en)
IEC 60721-3-3:2019/AMD1:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Classification of environmental conditions -
Part 3-3: Classification of groups of environmental parameters and their
severities - Stationary use at weatherprotected locations
AMENDMENT 1
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,
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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
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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.
Amendment 1 to IEC 60721-3-3:2019 has been prepared by IEC technical committee 104:
Environmental conditions, classification and methods of test.
The text of this Amendment is based on the following documents:
Draft Report on voting
104/1188/FDIS 104/1204/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
...