EN ISO 877-1:2025

SLOVENSKI STANDARD
01-november-2025
Nadomešča:
SIST EN ISO 877-1:2012
Polimerni materiali - Metode izpostavitve sončnemu obsevanju - 1. del: Splošna
navodila (ISO 877-1:2025)
Plastics - Methods of exposure to solar radiation - Part 1: General guidance (ISO 877-
1:2025)
Kunststoffe - Freibewitterung - Teil 1: Allgemeine Anleitung (ISO 877-1:2025)
Plastiques - Méthodes d'exposition au rayonnement solaire - Partie 1: Lignes directrices
générales (ISO 877-1:2025)
Ta slovenski standard je istoveten z: EN ISO 877-1:2025
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 877-1
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2025
EUROPÄISCHE NORM
ICS 83.080.01 Supersedes EN ISO 877-1:2010
English Version
Plastics - Methods of exposure to solar radiation - Part 1:
General guidance (ISO 877-1:2025)
Plastiques - Méthodes d'exposition au rayonnement Kunststoffe - Freibewitterung - Teil 1: Allgemeine
solaire - Partie 1: Lignes directrices générales (ISO Anleitung (ISO 877-1:2025)
877-1:2025)
This European Standard was approved by CEN on 18 August 2025.

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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 877-1:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 877-1:2025) 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 February 2026, and conflicting national standards
shall be withdrawn at the latest by February 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 877-1:2010.
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 877-1:2025 has been approved by CEN as EN ISO 877-1:2025 without any modification.

International
Standard
ISO 877-1
Second edition
Plastics — Methods of exposure to
2025-08
solar radiation —
Part 1:
General guidance
Plastiques — Méthodes d'exposition au rayonnement solaire —
Partie 1: Lignes directrices générales
Reference number
ISO 877-1:2025(en) © ISO 2025
ISO 877-1:2025(en)
© ISO 2025
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 877-1:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principle . 2
5 Apparatus . 3
5.1 General requirements .3
5.2 Apparatus for measurement of climatic factors .3
5.2.1 Apparatus for measurement of radiant exposure .3
5.2.2 Other climate-measuring instruments .4
6 Test specimens . 5
6.1 Form, shape and preparation .5
6.2 Number of test specimens .5
6.3 Conditioning and storage .6
7 Conditions of exposure of the test specimens . 6
7.1 Classes of climate .6
7.2 Types of exposure used for specimens .6
8 Exposure stages . 7
8.1 General considerations.7
8.2 Duration of exposure .7
8.3 Solar radiant exposure .7
8.3.1 Importance .7
8.3.2 Instrumental measurement of solar radiant exposure .7
9 Procedure . 8
9.1 Mounting of test specimens .8
9.2 Mounting of reference materials .8
9.3 Climatic observations .9
9.4 Exposure of test specimens .9
9.5 Determination of changes in properties, if required.9
10 Expression of results . 9
10.1 Determination of changes in properties .9
10.2 Levels (values) of exposure stages.9
10.3 Climatic conditions .9
11 Test report . 10
Annex A (informative) Classification of climates .12
Bibliography . 14

iii
ISO 877-1:2025(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 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
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 second edition cancels and replaces the first edition (ISO 877-1:2009), which has been technically
revised.
The main changes are as follows:
— addition of new term and definition (3.1) "natural weathering";
— addition of a requirement for the area beneath and in the vicinity of racks in 5.1;
— addition of new NOTE 2 in 9.2 referring to ISO/TR 19032;
— addition of information to be included in the test report (Clause 11).
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
ISO 877-1:2025(en)
Introduction
Outdoor-exposure tests of the type specified in the ISO 877 series are needed to evaluate the performance of
plastics when exposed to solar radiation. The results of such tests should be regarded only as an indication
of the effect of exposure to direct weathering (ISO 877-2:2025, method A) or to indirect weathering using
glass-filtered solar radiation (ISO 877-2:2025, method B) or to intensified solar radiation (ISO 877-3) by the
methods described. Results from tests conducted in accordance with any of the parts of the ISO 877 series
will show some variability when comparing results from repeat exposures conducted at the same location
at a different time. This is much more important for materials that show significant change after a year or
less of exposure. In general, results from repeat exposures at the same location are necessary to determine
the range of performance of a material subjected to exposure to solar radiation as specified in the ISO 877
series. Since the type of climate can have a significant effect on the rate and type of degradation, results from
exposures conducted in different types of climate are necessary to fully characterize the outdoor durability
of a material. For solar-concentrating exposures conducted in accordance with ISO 877-3, exposure duration
is defined in terms of the total solar UV radiant exposure. This reduces the effect of annual and seasonal
variations in solar ultraviolet radiation.
Fresnel-reflecting concentrators of the type described in ISO 877-3, are utilized to intensify natural solar
radiation, in an attempt to accelerate outdoor-exposure testing of plastics materials.
A system of classifying and characterizing climates in different parts of the world is given in Annex A.
The test method chosen is usually that designed to expose the material to the most severe conditions
associated with any particular climate. It should, therefore, be borne in mind that the severity of exposure
in actual use is, in most cases, likely to be less than that specified in this document, and allowance should be
made accordingly when interpreting the results. For example, vertical exposure at 90° from the horizontal
is considerably less severe in its effects on plastics than near-horizontal exposure, particularly in tropical
regions, where the sun is most powerful at high zenith angles.
Polar-facing surfaces are much less likely to be degraded than equator-facing surfaces because they are
less exposed to solar radiation. However, the fact that they can remain wet for longer periods can be of
significance for materials affected by moisture or for materials that are susceptible to microbial growth.

v
International Standard ISO 877-1:2025(en)
Plastics — Methods of exposure to solar radiation —
Part 1:
General guidance
1 Scope
This document provides information and general guidance on the selection and use of the methods of
exposure to solar radiation described in detail in subsequent parts of the ISO 877 series. These methods
of exposure to solar radiation are applicable to plastics materials of all kinds as well as to products and
portions of products.
It also specifies methods for determining radiant exposure.
It does not include direct weathering using black-box test fixtures, which simulate higher end-use
temperatures in some applications.
[1] [2]
NOTE ASTM G7 and ASTM D4141 describe black-box exposure tests.
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 291, Plastics — Standard atmospheres for conditioning and testing
ISO 472, Plastics — Vocabulary
ISO 877-2:2025, Plastics — Methods of exposure to solar radiation — Part 2: Direct weathering and exposure
behind window glass
ISO 877-3, Plastics — Methods of exposure to solar radiation — Part 3: Intensified weathering using concentrated
solar radiation
ISO 2818, Plastics — Preparation of test specimens by machining
ISO 4582, Plastics — Determination of changes in colour and variations in properties after exposure to glass-
filtered solar radiation, natural weathering or laboratory radiation sources
ISO 4892-1, Plastics — Methods of exposure to laboratory light sources — Part 1: General guidance and
requirements
ISO 9370, Plastics — Instrumental determination of radiant exposure in weathering tests — General guidance
and basic test method
ISO 10640, Plastics — Methodology for assessing polymer photoageing by FTIR and UV/visible spectroscopy
ASTM G179, Standard Specification for Metal Black Panel and White Panel Temperature Devices for Natural
Weathering Tests
ASTM G183, Standard Practice for Field Use of Pyranometers, Pyrheliometers and UV Radiometers

ISO 877-1:2025(en)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472, ISO 4892-1, ISO 9370 and the
following apply.
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/
3.1
natural weathering
outdoor exposure of materials to unconcentrated sunlight, the purpose of which is to assess the effects of
environmental factors on various functional and decorative parameters of interest
4 Principle
Specimens or, if required, sheets or other shapes from which specimens can be cut, are exposed to
natural solar radiation (see ISO 877-2:2025, method A), or to window-glass-filtered solar radiation (see
ISO 877-2:2025, method B) or to intensified solar radiation using a Fresnel-reflecting concentrator (see
ISO 877-3). After the prescribed exposure period, the specimens are removed from exposure and, if a
characterization is required, tested for changes in optical, mechanical or other properties of interest. The
exposure stage can be a given period of time or can be expressed in terms of a given total radiant exposure
or UV radiant exposure. The latter is preferred whenever the main objective of the exposure is to determine
resistance to solar radiation, since it minimizes the effect of variations in spectral irradiance with climate,
location and time.
NOTE 1 Exposures with the same total or UV radiant exposure in different climates, locations and periods can still
result in different rate and type of degradation.
Instrumental means of measuring irradiance, and means for integration to give the radiant exposure over a
period of time, are preferred.
NOTE 2 Physical standard materials that change in colour, or another property, upon exposure to solar radiation
have been used to determine radiant exposures. Determinations of radiant exposure using these procedures are less
reliable indicators than determination of radiant exposure by actual measurement of solar radiation.
When comparing the results of exposure using ISO 877-2:2025, method A or B, with ISO 877-3, differences
in specimen temperatures, ultraviolet radiant exposure levels and moisture deposition should be taken
into account. Additionally, when comparing ISO 877-2:2025, method B, to ISO 877-3, the glass or other
transparent material used as the filter shall be identical. Comparison of results from ISO 877-3 to those from
ISO 877-2:2025, method A or B, shall be based on equal radiant exposure levels.
The climatic conditions during the test may be monitored and reported with the other conditions of
exposure.
A similar material of known behaviour should be exposed simultaneously with the experimental material as
a control.
Unless otherwise specified, test pieces for the determination of change in colour and change in mechanical
properties are exposed in a mechanically unstressed state.
ISO 877-2:2025, method B, excludes the effects of wind and rain and can reduce the effect of dew. The devices
used for ISO 877-3 are typically equipped to provide moisture in the form of water spray.
Exposures in hot and wet and in hot and dry climates are often used to benchmark the outdoor durability of
materials such as plastics. Information on climate classification can be found in Annex A.
NOTE 3 Further detailed information about the effects of different climates and different exposure parameters on
[3]
the variability of results from outdoor exposures can be found in ASTM G141.

ISO 877-1:2025(en)
5 Apparatus
5.1 General requirements
Exposure equipment consisting essentially of an appropriate test rack shall be used. The rack, specimen
holders and other fixtures shall be made from inert materials that will not affect the test results. Noncorrosive
aluminium alloy, stainless steel and ceramics have been found to be suitable. Untreated wood may be used,
but can be subject to rot at locations high in moisture. Wood treated with preservatives, copper or its alloys,
zinc or its alloys, iron or non-galvanized steel shall not be used. Materials with different thermal properties
can affect the surface temperature and therefore the test results. Copper or its alloys, zinc or its alloys, iron
or steels other than stainless steels, galvanized or plated metals or timbers other than those above should
preferably not be used in the vicinity of the test specimens.
The area beneath and in the vicinity of the racks shall be characterized by low reflectance and by ground
cover typical of that climatological area. In desert areas, the racks shall be located on gravel, in most
temperate areas on low-cut grass. Other ground covers may be used with the agreement of all parties and
shall be included in the test report.
NOTE 1 The use of other ground covers can affect test results.
If backing is necessary to support the test specimens or to simulate special end-use conditions, such backing
shall be of inert material. Test specimens that require support to prevent sagging of the specimen but do not
require backing to elevate the temperature, or require no “solid” backing, should preferably be supported
with fine-strand wire netting or slit-expanded aluminium or stainless-steel backing. Use 16-gauge to
18-gauge metal with approximately 12 mm to 13 mm openings. The surface area of the wire netting should
be 60 % to 70 % open.
NOTE 2 Metric values for 16 gauge and 18 gauge are defined differently depending on the type of metal. Typical
ranges for 16 gauge to 18 gauge are 1,2 mm to 1,5 mm for sheet steel; 1,0 mm to 1,3 mm for aluminium; and 1,3 mm to
1,6 mm for stainless steel.
For tests on finished products, wherever possible, the fixtures should closely simulate those used in practice.
Requirements for rack design for outdoor exposures shall be in accordance with ISO 877-2, and specific
requirements for the solar concentrator shall be in accordance with ISO 877-3.
5.2 Apparatus for measurement of climatic factors
5.2.1 Apparatus for measurement of radiant exposure
5.2.1.1 General
All radiometers used to measure radiant exposure shall meet the requirements of ISO 9370.
A calibration of the radiometers shall be conducted regularly, being traceable to national/international
radiometric references. The recommended recalibration procedure and intervals can be provided by the
equipment manufacturer.
When none of this information is available, a calibration should be performed at least annually.
In any case, the recalibration intervals shall be justified and documented.
[14]
NOTE ISO 10012 provides information for setting the calibration interval.
Examples of instruments used to measure radiant exposure are listed in 5.2.1.2 to 5.2.1.5.

ISO 877-1:2025(en)
5.2.1.2 Pyranometers
A pyranometer is a radiometer used to measure global solar radiation if mounted horizontally, or
hemispherical radiation if mounted at an angle. Pyranometers shall meet or exceed the requirements for a
second-class pyranometer as specified in ISO 9370.
5.2.1.3 Pyrheliometers
A pyrheliometer is a radiometer used to measure the direct component of solar irradia
...