EN ISO 877-3:2026
(Main)Plastics - Methods of exposure to solar radiation - Part 3: Intensified weathering using concentrated solar radiation (ISO 877-3:2026)
- Abstract
This document specifies a method for exposing plastics to concentrated solar radiation using reflecting concentrators to accelerate the weathering processes. The purpose is to assess property changes produced after specified stages of such exposures. The reflecting concentrators used in these exposures are sometimes referred to as “Fresnel reflectors” because, in cross-section, the array of mirrors used to concentrate the solar radiation resembles the cross-section of a Fresnel lens.
General guidance concerning the scope of the ISO 877 series is given in ISO 877-1.
NOTE Additional information about solar concentrating exposures, including a partial list of standards in which they are specified, is given in the Bibliography.
- Status
- Published
- Publication Date
- 26-May-2026
- Technical Committee
- CEN/TC 249 - Plastics
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 27-May-2026
- Completion Date
- 27-May-2026
EN ISO 877-3:2026 is a CEN European Standard that adopts ISO 877-3:2026 for plastics weathering. It specifies a method for exposing plastics to concentrated solar radiation using reflecting concentrators, so users can assess property changes after defined exposure stages. It is used by laboratories, materials engineers, quality teams, and buyers who need a controlled accelerated outdoor weathering procedure.
What does EN ISO 877-3:2026 specify?
EN ISO 877-3:2026 specifies intensified weathering of plastics by concentrated solar radiation. The method uses reflecting concentrators, sometimes called Fresnel reflectors, to accelerate weathering and then assess property changes after set exposure stages.
The document is part of the ISO 877 series. General guidance for the series is given in ISO 877-1, and ISO 877-2 covers direct weathering and exposure behind window glass. EN ISO 877-3:2026 is organized into clauses 1 to 11, followed by a bibliography.
What are the key requirements of EN ISO 877-3:2026?
EN ISO 877-3:2026 sets out the test equipment, exposure conditions, specimen mounting, exposure stages, reporting, and result expression needed for concentrated-sunlight weathering. In practice, the standard is not just about placing a sample outdoors - it also controls the device, the temperature, the wetting cycle, and the way exposure is reported.
Apparatus and measurement setup - Clause 5 requires the solar concentrating device, its operation, and measurement of solar radiation in the specimen exposure area to follow ASTM G90. Climatic measurement equipment follows ISO 877-1. This matters because the test depends on a defined concentrator and a defined way of measuring what the specimen actually receives.
Exposure site conditions - Clause 7.2 says Fresnel-reflecting concentrator devices work best at sites with at least 3 500 h of sunshine per year and average daytime relative humidity below 30 %. The practical point is that diffuse light and high humidity reduce the amount of usable UV focused onto the specimens, which can change degradation behavior and material ranking.
Temperature control - Clause 7.3 explains that the device uses a blower to cool the specimens, and that specimen temperatures are typically about 10 °C higher than direct un-concentrated solar exposure at normal incidence. If tighter control is needed, the standard allows temperature monitoring by black-panel, white-panel, black-standard, specimen, air, or remote sensors, with the controlled temperature and deviations reported. This matters because temperature strongly affects weathering rate.
Irradiance control - Clause 7.4 allows irradiance to be varied by changing the number of mirrors in the device, but any change to irradiance and the method used to calculate or measure it must be fully described in the test report. In practice, this means irradiance changes also change temperature and exposure time, so the setting must be recorded.
Exposure stages - Clause 8.1 states that exposure stages are defined by total solar radiant exposure, solar UV radiant exposure, or narrow-passband UV radiant exposure unless otherwise specified. This lets users target a radiation dose instead of only a time period, which is more useful for comparing weathering performance.
Specimen mounting - Clause 9.1 requires the exposed surface to face the mirrors and limits specimen-plus-backing thickness to 13 mm to allow adequate cooling. The standard also gives mounting guidance for unbacked and insulated backed exposures. This matters because specimen position affects both cooling and uniformity of exposure.
Water spray cycles and under-glass testing - Clause 9.4 and Table 2 define the spray cycles used with Fresnel-reflecting concentrators. Cycle selection depends on how much spray is wanted, and cycle 3 is used for under-glass testing, with the glass characteristics taken from ISO 877-2. For under-glass exposures, airflow should be as high as possible, and the glass transmission must be reported.
Results and test report - Clause 10 requires changes in properties to be determined using suitable ISO procedures and test methods, with ISO 4582 cited for evaluating changes after exposure. Clause 11 requires reporting of the spray cycle, glass transmission for under-glass exposures, the temperature-control thermometer type, the mean controlled temperature and variation, and any irradiance reduction. This makes test results traceable and comparable between laboratories.
Who uses EN ISO 877-3:2026?
EN ISO 877-3:2026 is used by laboratories, plastics producers, product development teams, quality managers, and buyers who need to compare weathering resistance. It is relevant wherever plastics are exposed to sunlight outdoors and the user wants an accelerated procedure that concentrates solar radiation.
The document is especially relevant for teams evaluating appearance changes, surface degradation, or other property changes after exposure. It is also useful when a specification, product qualification program, or supplier comparison needs a repeatable outdoor weathering method with defined dose, wetting, and temperature reporting.
What changed in EN ISO 877-3:2026 from the previous edition?
EN ISO 877-3:2026 supersedes EN ISO 877-3:2018. The foreword states that the third edition technically revises the second edition.
The changes named in the document are:
- size requirements were added in 7.3
- a second formula was added in 10.2.4
- a new 10.2.5, “Radiation measurement”, was added and the later clauses were renumbered
Which standards are used with EN ISO 877-3:2026?
EN ISO 877-3:2026 relies on several named standards for general guidance, apparatus rules, measurement methods, and related exposure procedures.
- ISO 877-1 - gives general guidance for the ISO 877 series and is also used for climatic measurements, specimen requirements, observations, and test reporting.
- ISO 877-2:2025 - provides the companion method for direct weathering and exposure behind window glass, and is used for glass characteristics in under-glass testing.
- ISO 4892-1 - gives general requirements for laboratory light-source exposure methods and is used for white-standard thermometer requirements.
- ASTM G90 - governs the concentrating device, its operation, exposure site requirements, orientation of mirrors, and radiation measurement within the specimen exposure area.
- ASTM G179 - gives requirements for black-panel and white-panel temperature devices used for temperature measurement and control.
What does the EN ISO 877-3:2026 document contain?
EN ISO 877-3:2026 contains the method description, apparatus requirements, specimen mounting rules, exposure conditions, exposure stage guidance, result expression, and test report content needed for intensified weathering with concentrated solar radiation. It also includes three figures showing the apparatus layouts and the reflecting mechanism, plus Table 1 for annual solar and UV exposure guidance and Table 2 for spray cycles.
Clause 10 gives the calculation and measurement approach for exposure levels and the radiation measurements used to express results. Clause 11 defines what has to be recorded in the report so that the exposure can be reproduced or compared later.
Relations
- Effective Date
- 25-Oct-2023
- Effective Date
- 12-Aug-2026
- Effective Date
- 12-Aug-2026
- Effective Date
- 03-Jun-2026
- Referred By
CEN/TS 15534-3:2007 - Wood-plastics composites (WPC) - Part 3: Characterisation of WPC products - Effective Date
- 03-Jun-2026
- Effective Date
- 03-Jun-2026
- Effective Date
- 03-Jun-2026
- Effective Date
- 03-Jun-2026
- Effective Date
- 03-Jun-2026
- Effective Date
- 03-Jun-2026
- Consolidated By
ISO 877-3:2026 - Plastics — Methods of exposure to solar radiation — Part 3: Intensified weathering using concentrated solar radiation - Effective Date
- 12-Feb-2026
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Frequently Asked Questions
EN ISO 877-3:2026 is a standard published by the European Committee for Standardization (CEN). Its full title is "Plastics - Methods of exposure to solar radiation - Part 3: Intensified weathering using concentrated solar radiation (ISO 877-3:2026)". This standard covers: This document specifies a method for exposing plastics to concentrated solar radiation using reflecting concentrators to accelerate the weathering processes. The purpose is to assess property changes produced after specified stages of such exposures. The reflecting concentrators used in these exposures are sometimes referred to as “Fresnel reflectors” because, in cross-section, the array of mirrors used to concentrate the solar radiation resembles the cross-section of a Fresnel lens. General guidance concerning the scope of the ISO 877 series is given in ISO 877-1. NOTE Additional information about solar concentrating exposures, including a partial list of standards in which they are specified, is given in the Bibliography.
This document specifies a method for exposing plastics to concentrated solar radiation using reflecting concentrators to accelerate the weathering processes. The purpose is to assess property changes produced after specified stages of such exposures. The reflecting concentrators used in these exposures are sometimes referred to as “Fresnel reflectors” because, in cross-section, the array of mirrors used to concentrate the solar radiation resembles the cross-section of a Fresnel lens. General guidance concerning the scope of the ISO 877 series is given in ISO 877-1. NOTE Additional information about solar concentrating exposures, including a partial list of standards in which they are specified, is given in the Bibliography.
EN ISO 877-3:2026 is classified under the following ICS (International Classification for Standards) categories: 83.080.01 - Plastics in general. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 877-3:2026 has the following relationships with other standards: It is inter standard links to EN ISO 877-3:2018, ISO 877-1:2025, ISO 877-2:2025, CEN/TS 15354:2006, CEN/TS 15534-3:2007, CEN/TS 15534-1:2007, EN 15354:2022, EN 15132:2006, EN 10245-1:2011, EN 62282-4-101:2014, ISO 877-3:2026. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN ISO 877-3:2026 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-julij-2026
Polimerni materiali - Metode izpostavitve vremenskim vplivom - 3. del: Pospešeni
vremenski vplivi z uporabo koncentriranega sončnega sevanja (ISO 877-3:2026)
Plastics - Methods of exposure to solar radiation - Part 3: Intensified weathering using
concentrated solar radiation (ISO 877-3:2026)
Kunststoffe - Freibewitterung - Teil 3: Beschleunigte Bewitterung mit gebündelter
Sonnenstrahlung (ISO 877-3:2026)
Plastiques - Méthodes d'exposition au rayonnement solaire - Partie 3: Exposition
intensifiée par rayonnement solaire concentré (ISO 877-3:2026)
Ta slovenski standard je istoveten z: EN ISO 877-3:2026
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 877-3
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2026
EUROPÄISCHE NORM
ICS 83.080.01 Supersedes EN ISO 877-3:2018
English Version
Plastics - Methods of exposure to solar radiation - Part 3:
Intensified weathering using concentrated solar radiation
(ISO 877-3:2026)
Plastiques - Méthodes d'exposition au rayonnement Kunststoffe - Freibewitterung - Teil 3: Beschleunigte
solaire - Partie 3: Exposition intensifiée par Bewitterung mit gebündelter Sonnenstrahlung (ISO
rayonnement solaire concentré (ISO 877-3:2026) 877-3:2026)
This European Standard was approved by CEN on 20 May 2026.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 877-3:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 877-3:2026) has been prepared by Technical Committee ISO/TC 61 "Plastics" in
collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by SIS.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2026, and conflicting national standards
shall be withdrawn at the latest by November 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 877-3:2018.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 877-3:2026 has been approved by CEN as EN ISO 877-3:2026 without any modification.
International
Standard
ISO 877-3
Third edition
Plastics — Methods of exposure to
2026-05
solar radiation —
Part 3:
Intensified weathering using
concentrated solar radiation
Plastiques — Méthodes d'exposition au rayonnement solaire —
Partie 3: Exposition intensifiée par rayonnement solaire
concentré
Reference number
ISO 877-3:2026(en) © ISO 2026
ISO 877-3:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 877-3:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
5.1 General requirements .2
5.2 Apparatus for measurement of climatic factors .3
6 Test specimens . 3
7 Exposure conditions . 4
7.1 Orientation of mirrors .4
7.2 Exposure site.4
7.3 Temperature control .4
7.4 Irradiance level .5
8 Exposure stages . 6
8.1 General .6
8.2 Solar radiant exposure .6
8.2.1 Guidance for selection of the exposure stage .6
8.2.2 Instrumental measurement of solar radiant exposure .6
9 Procedure . 7
9.1 Mounting of test specimens .7
9.2 Mounting of reference materials (if used) .7
9.3 Climatic observations .7
9.4 Exposure of test specimens .7
9.4.1 General .7
9.4.2 Exposure cycles .7
9.4.3 Testing under glass.7
10 Expression of results . 8
10.1 Determination of changes in properties .8
10.2 Climatic conditions and observations .8
10.2.1 General .8
10.2.2 Temperature .8
10.2.3 Relative humidity .8
10.2.4 Levels (values) of exposure stages .8
10.2.5 Radiation measurement.9
10.2.6 Precipitation .9
10.2.7 Time of wetness .9
10.2.8 Other observations .9
11 Test report . 9
Bibliography .10
iii
ISO 877-3:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO 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, ISO had 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
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 6, Ageing,
chemical and environmental resistance, in collaboration with the European Committee for Standardization
(CEN) Technical Committee CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 877-3:2018), which has been technically
revised.
The main changes are as follows:
— size requirements in 7.3 have been added;
— in 10.2.4, a second formula has been added;
— a new 10.2.5 “Radiation measurement” has been added and subsequent clauses have been renumbered.
A list of all parts in the ISO 877 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
International Standard ISO 877-3:2026(en)
Plastics — Methods of exposure to solar radiation —
Part 3:
Intensified weathering using concentrated solar radiation
1 Scope
This document specifies a method for exposing plastics to concentrated solar radiation using reflecting
concentrators to accelerate the weathering processes. The purpose is to assess property changes produced
after specified stages of such exposures. The reflecting concentrators used in these exposures are sometimes
referred to as “Fresnel reflectors” because, in cross-section, the array of mirrors used to concentrate the
solar radiation resembles the cross-section of a Fresnel lens.
General guidance concerning the scope of the ISO 877 series is given in ISO 877-1.
NOTE Additional information about solar concentrating exposures, including a partial list of standards in which
they are specified, is given in the Bibliography.
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.
ISO 877-1, Plastics — Methods of exposure to solar radiation — Part 1: General guidance
ISO 877-2:2025, Plastics — Methods of exposure to solar radiation — Part 2: Direct weathering and exposure
behind window glass
ISO 4892-1, Plastics — Methods of exposure to laboratory light sources — Part 1: General guidance and
requirements
ASTM G90, Standard Practice for Performing Accelerated Outdoor Weathering of Nonmetallic Materials Using
Concentrated Natural Sunlight
ASTM G179, Standard Specification for Metal Black Panel and White Panel Temperature Devices for Natural
Weathering Tests
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
This document describes a method for performing accelerated weathering on plastics using intensified solar
radiation. General guidance is given in ISO 877-1.
ISO 877-3:2026(en)
5 Apparatus
5.1 General requirements
General
...