EN ISO 18526-2:2020

Eye and face protection - Test methods - Part 2 : Physical optical properties (ISO 18526-2:2020)

This document specifies the reference test methods for determining the physical optical properties of personal eye and face protectors.
This document does not apply to any eye and face protection products for which the requirements standard(s) specifies other test methods.
Other test methods can be used provided they have been shown to be equivalent and include uncertainties of measurement no greater than those required of the reference method.

Augen- und Gesichtsschutz - Prüfverfahren - Teil 2: Physikalisch optische Eigenschaften (ISO 18526-2:2020)

Dieses Dokument legt die Bezugsprüfverfahren für die Bestimmung der physikalisch-optischen Eigenschaften von persönlichen Augen- und Gesichtsschutzgeräten fest.
Dieses Dokument gilt nicht für etwaige Anforderungsnormen für Augen- und Gesichtsschutzprodukte, für die andere Prüfverfahren festgelegt sind.
Andere Prüfverfahren können angewendet werden, sofern ihre Gleichwertigkeit nachgewiesen ist und ihre Präzision die für das Referenzverfahren geforderte nicht übersteigt.

Protection des yeux et du visage - Méthodes d'essai - Partie 2: Propriétés optiques physiques (ISO 18526-2:2020)

Le présent document spécifie les méthodes d'essai de référence pour la détermination des propriétés optiques physiques des équipements de protection individuelle des yeux et du visage.
Le présent document ne s'applique à aucun produit relatif à la protection des yeux et du visage pour lequel les normes d'exigences spécifient d'autres méthodes d'essai.
D'autres méthodes d'essai peuvent être utilisées à condition que leur équivalence ait été démontrée et si les incertitudes de mesure qui leur sont associées n'excèdent pas celles exigées par la méthode de référence.

Varovanje oči in obraza - Preskusne metode - 2. del: Fizikalne optične lastnosti (ISO 18526-2:2020)

General Information

• Status: Published
• Publication Date: 10-Mar-2020
• ICS: 13.340.20 - Head protective equipment
• Technical Committee: CEN/TC 85 - Eye-protective equipment
• Drafting Committee: CEN/TC 85 - Eye-protective equipment
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 11-Mar-2020
• Completion Date: 11-Mar-2020
• Directive: 2016/425 - Regulation (EU) 2016/425 of the European Parliament and of the Council of 9 March 2016 on personal protective equipment and repealing Council Directive 89/686/EEC
• Ref Project: SIST EN ISO 18526-2:2020 - Eye and face protection - Test methods - Part 2 : Physical optical properties (ISO 18526-2:2020)

Relations

• Replaces: EN 174:2001 - Personal eye-protection - Ski goggles for downhill skiing
• Effective Date: 19-Nov-2025
• Replaces: EN 379:2003+A1:2009 - Personal eye-protection - Automatic welding filters
• Effective Date: 19-Feb-2025
• Replaces: EN 167:2001 - Personal eye-protection - Optical test methods
• Effective Date: 04-Sep-2024
• Replaces: EN 168:2001 - Personal eye-protection - Non-optical test methods
• Effective Date: 04-Sep-2024

Overview

EN ISO 18526-2:2020 - Eye and face protection - Test methods - Part 2: Physical optical properties - is a CEN-adopted ISO reference standard that specifies test methods for determining the physical optical properties of personal eye and face protectors. It defines measurement principles, uncertainty requirements and reporting formats for optical performance metrics used in PPE evaluation. This document is a reference for laboratories and manufacturers assessing filter and lens optical performance and does not apply when a product requirements standard mandates different methods. Alternative methods may be used only if demonstrated equivalent and having measurement uncertainties no greater than the reference method.

Key topics and technical requirements

The standard organizes test methods and reporting rules for core optical characteristics, including:

• Luminous transmittance - calculation from spectral values, broadband measurement procedures, uniformity checks, and matching between left/right reference points.
• Ultraviolet (UV) transmittance - spectral and mean values, solar UV, UV‑A and UV‑B metrics and reporting requirements.
• Blue‑light transmittance - solar and artificial-source calculations and broadband measurement methods.
• Infrared (IR) transmittance - near‑IR, IR‑A, IR‑B and solar IR measurement/calculation guidance.
• Spectral reflectance - specular, total (specular included/excluded) and defined measurement geometries (e.g., 0°/45°).
• Luminous reflectance and scattered light - measurement and reporting conventions for visual performance.
• General test rules - positioning/direction of measurement, prescribed wavelength intervals, uncertainty of measurement and required contents of the test report.

The standard emphasizes traceable measurement, specified uncertainty limits, and standardized reporting to ensure comparability across test labs and manufacturers.

Applications

EN ISO 18526-2:2020 is practical for:

• Manufacturers validating optical performance of safety goggles, face shields and filter lenses.
• Accredited test laboratories performing certification, conformance testing and product development.
• Certification and regulatory authorities verifying compliance with optical properties required by PPE product standards.
• R&D and design teams optimizing lens coatings, tints and filters to meet user-visibility and protection criteria.

Who should use this standard

• PPE manufacturers and quality engineers
• Independent testing and calibration laboratories
• Certification bodies and compliance assessors
• Occupational safety professionals and product designers

Related standards

This document is part of the ISO/CEN framework for eye and face protection test methods. Product requirement standards or other parts of the test-method series may specify different or additional methods; EN ISO 18526-2:2020 is the reference approach for physical optical property measurements unless superseded by a specific requirements standard.

Keywords: EN ISO 18526-2:2020, eye and face protection, test methods, optical properties, luminous transmittance, UV transmittance, blue-light, infrared, spectral reflectance, PPE testing.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2020
Varovanje oči in obraza - Preskusne metode - 2. del: Fizikalne optične lastnosti
(ISO 18526-2:2020)
Eye and face protection - Test methods - Part 2 : Physical optical properties (ISO 18526-
2:2020)
Augen- und Gesichtsschutz - Prüfverfahren - Teil 2: Physikalisch optische Eigenschaften
(ISO 18526-2:2020)
Protection des yeux et du visage - Méthodes d'essai - Partie 2: Propriétés optiques
physiques (ISO 18526-2:2020)
Ta slovenski standard je istoveten z: EN ISO 18526-2:2020
ICS:
13.340.20 Varovalna oprema za glavo Head protective equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 18526-2
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2020
EUROPÄISCHE NORM
ICS 13.340.20
English Version
Eye and face protection - Test methods - Part 2 : Physical
optical properties (ISO 18526-2:2020)
Protection des yeux et du visage - Méthodes d'essai - Augen- und Gesichtsschutz - Prüfverfahren - Teil 2:
Partie 2: Propriétés optiques physiques (ISO 18526- Physikalisch optische Eigenschaften (ISO 18526-
2:2020) 2:2020)
This European Standard was approved by CEN on 25 January 2020.

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, Turkey 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
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18526-2:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 18526-2:2020) has been prepared by Technical Committee ISO/TC 94
"Personal safety -- Personal protective equipment" in collaboration with Technical Committee CEN/TC
85 “Eye protective equipment” the secretariat of which is held by AFNOR.
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 September 2020, and conflicting national standards
shall be withdrawn at the latest by September 2020.
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.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 18526-2:2020 has been approved by CEN as EN ISO 18526-2:2020 without any
modification.
INTERNATIONAL ISO
STANDARD 18526-2
First edition
2020-02
Eye and face protection — Test
methods —
Part 2:
Physical optical properties
Protection des yeux et du visage — Méthodes d'essai —
Partie 2: Propriétés optiques physiques
Reference number
ISO 18526-2:2020(E)
©
ISO 2020
ISO 18526-2:2020(E)
© ISO 2020
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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

ISO 18526-2:2020(E)
Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Preparatory information . 1
5 General test requirements . 2
6 Test methods for measuring transmittance — General . 2
6.1 Uncertainty of measurement . 2
6.2 Reporting compliance . 3
6.3 Applicability . 3
6.4 Position and direction of measurement . 3
6.5 Wavelength intervals . 3
6.6 Test report . 3
7 Luminous transmittance . 3
7.1 Calculations of luminous transmittance from spectral values . . 3
7.2 Test report . 3
7.3 Broadband method of measurement of luminous transmittance . 4
7.3.1 Apparatus . 4
7.3.2 Calibration . 4
7.3.3 Procedure . 4
7.3.4 Test reports for luminous transmittance values . 4
7.4 Measurement of uniformity of luminous transmittance . 4
7.4.1 Unmounted filter covering one eye . 4
7.4.2 Filter covering both eyes . 6
7.5 Transmittance matching at right and left reference points . 9
7.5.1 Test method . 9
7.5.2 Calculations .10
7.5.3 Test report .10
8 Ultraviolet transmittance .10
8.1 General .10
8.2 Spectral transmittance and mean spectral transmittance .10
8.3 Solar UV transmittance .10
8.4 Solar UV-A transmittance .10
8.5 Solar UV-B transmittance .10
8.6 Mean UV-A transmittance .10
8.7 Mean UV-B transmittance .11
8.8 Mean 380 nm to 400 nm transmittance .11
8.9 Test report .11
9 Blue-light transmittance .11
9.1 Solar blue-light transmittance .11
9.1.1 Calculation of solar blue-light transmittance from spectral values .11
9.1.2 Broadband method of measurement of solar blue-light transmittance .11
9.2 Blue-light transmittance from artificial sources .11
9.2.1 Calculation of blue-light transmittance from artificial sources from
spectral values .11
9.2.2 Broadband method of measurement of blue-light transmittance from
artificial sources .12
9.2.3 Test report .12
10 IR transmittance .12
ISO 18526-2:2020(E)
10.1 Near IR transmittance.12
10.1.1 Calculation .12
10.2 IR-A transmittance .12
10.2.1 Calculation .12
10.3 IR-B transmittance .12
10.3.1 Calculation .12
10.4 Solar IR transmittance .12
10.4.1 Calculation .12
10.5 Test report .12
11 Relative visual attenuation coefficient for traffic signal light detection, Q .13
signal
11.1 Calculation .13
11.2 Test report .13
12 Spectral reflectance .13
12.1 Uncertainty of measurement .13
12.2 Position and direction of measurement .13
12.2.1 Specular spectral reflectance .13
12.2.2 Total spectral reflectance (specular included) . .13
12.2.3 Total spectral reflectance (specular excluded) .14
12.2.4 0°/45° and 45°/0° geometry .14
12.3 Wavelength intervals .14
12.4 Test report .14
13 Luminous reflectance .14
13.1 Calculations .14
13.2 Test report .14
13.3 Luminous reflectance of mesh .14
14 Scattered light .15
14.1 Wide angle scatter .15
14.1.1 Principle .15
14.1.2 Apparatus .15
14.1.3 Test sample .16
14.1.4 Test procedure .16
14.1.5 Calculation .16
14.1.6 Test report .17
14.2 Narrow angle scatter .17
14.2.1 Principle .17
14.2.2 Test methods .18
14.2.3 Test report .23
15 Polarization .23
15.1 Plane of transmission .23
15.1.1 Apparatus .23
15.1.2 Test procedure .23
15.1.3 Test report .24
15.2 Polarizing efficiency .24
15.2.1 Principle .24
15.2.2 Test procedure for the spectrophotometric method .25
15.2.3 Test report .25
15.2.4 Test procedure for the broadband method .25
15.2.5 Test report .26
16 Photochromic lenses .26
16.1 Light source(s) to approximate the spectral distribution of solar radiation for air
mass 2 for testing .26
16.1.1 Radiation source using one lamp .26
16.1.2 Radiation source using two lamps . .27
16.2 Conditioning for luminous transmittance in the faded state .27
16.3 Measurement .28
iv © ISO 2020 – All rights reserved

ISO 18526-2:2020(E)
16.3.1 Principle .28
16.3.2 Faded state .28
16.3.3 Darkened states .28
17 Automatic welding filters .29
17.1 General .29
17.2 Luminous transmittance in the light state .29
17.2.1 Measurement .29
17.2.2 Test report .30
17.3 Luminous transmittance in the dark state .30
17.3.1 Measurement .30
17.3.2 Test report .30
17.4 Shade number of welding filters with automatic shade number setting .30
17.4.1 Principle .30
17.4.2 Apparatus .31
17.4.3 Test procedure .31
17.4.4 Test report .31
17.5 Luminous transmittance variation over time.31
17.5.1 Principle .31
17.5.2 Apparatus .32
17.5.3 Test procedure .32
17.5.4 Test report .32
17.6 Blue-light transmittance for artificial sources .32
17.6.1 Measurement .32
17.6.2 Test report .32
17.7 Uniformity of luminous transmittance for flat filters .32
17.7.1 Filter covering both eyes .32
17.8 Angular dependence of luminous transmittance for flat filters .33
17.8.1 Principle .33
17.8.2 Apparatus .33
17.8.3 Test procedure .34
17.8.4 Test report .37
17.9 Angular dependence and uniformity of luminous transmittance for curved filters .37
17.9.1 Principle .37
17.9.2 Apparatus .37
17.9.3 Procedure .38
17.9.4 Test report .39
17.10 Transmittance matching at right and left reference points .39
17.10.1 Procedure .39
17.10.2 Test report .39
17.11 Switching time .39
17.11.1 Principle .39
17.11.2 Apparatus .39
17.11.3 Procedure .39
17.11.4 Uncertainty of measurement .40
17.11.5 Test report .40
17.12 Holding time .40
17.12.1 Principle .40
17.12.2 Apparatus .40
17.12.3 Procedure .40
17.12.4 Uncertainty of measurement .40
17.12.5 Test report .40
17.13 Manual control of dark state .40
17.13.1 Procedure .40
17.13.2 Test report .41
17.14 Optical sensitivity of welding detection .41
17.14.1 Principle .41
17.14.2 Apparatus .41
17.14.3 Measuring equipment .42
ISO 18526-2:2020(E)
17.14.4 Trigger light source (L) .43
17.14.5 Calibration procedure for the trigger light source (L) .44
17.14.6 Higher intensity light source (I) .44
17.14.7 Lower intensity light source (F) .45
17.14.8 Test procedure .46
17.14.9 Test report .46
Annex A (normative) Application of uncertainty of measurement .47
Annex B (informative) Sources of uncertainty in spectrophotometry and their estimation
and control .50
Annex C (informative) Definitions in summation form .58
Annex D (normative) Spectral functions for the calculation of transmittance and
reflectance values .63
Annex E (informative) Generic description of automatic welding filters and guidance on
illumination during testing .73
Bibliography .77
vi © ISO 2020 – All rights reserved

ISO 18526-2:2020(E)
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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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 Committe ISO/TC 94, Personal safety — Protective protective
equipment, Subcommittee SC 6, Eye and face protection.
This first edition of ISO 18526-2, together with ISO 18526-1, cancels and replaces ISO 4854:1981.
A list of all parts in the ISO 18526 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.
ISO 18526-2:2020(E)
Introduction
This family of documents comprised of the ISO 16321 series, the ISO 18526 series and the ISO 18527
series was developed in response to the worldwide stakeholders' demand for minimum requirements
and test methods for eye and face protectors traded internationally. ISO 4007 gives the terms and
definitions for all the various product types. The test methods are given in the ISO 18526 series, while
the requirements for occupational eye and face protectors are given in the ISO 16321 series. Eye
protectors for specific sports are mostly dealt with by the ISO 18527 series. A guidance document,
ISO 19734, for the selection, use and maintenance of eye and face protectors is under preparation.
viii © ISO 2020 – All rights reserved

INTERNATIONAL STANDARD ISO 18526-2:2020(E)
Eye and face protection — Test methods —
Part 2:
Physical optical properties
1 Scope
This document specifies the reference test methods for determining the physical optical properties of
personal eye and face protectors.
This document does not apply to any eye and face protection products for which the requirements
standard(s) specifies other test methods.
Other test methods can be used provided they have been shown to be equivalent and include
uncertainties of measurement no greater than those required of the reference method.
2 Normative references
The following documents are referred to 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 4007, Personal protective equipment — Eye and face protection — Vocabulary
ISO/CIE 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
ISO 11664-2, Colorimetry — Part 2: CIE standard illuminants
CIE 15:2019, Colorimetry
CIE S 017, International lighting vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4007 and CIE S 017 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Preparatory information
Before testing, refer to the appropriate product's requirements standard for the information needed to
apply the tests in this document, for example:
1)
— the number of test samples ;
— preparation of test samples;
1) For the purpose of this document, “test sample” is taken to be the object under test, e.g. “ocular”, “lens”, “filter”,
or “complete protector” as specified in the requirements standard.
ISO 18526-2:2020(E)
— the selection of test samples (if included in this document);
— any prior conditioning or testing;
— test method (if more than one is included in this document);
— any deviations from the method(s);
— characteristics to be assessed subjectively (if appropriate);
— pass/ fail criteria.
5 General test requirements
Unless otherwise specified, the values stated in this document are expressed as nominal values. Except
for temperature limits, values that are not stated as maxima or minima should be subject to a tolerance
of ±5 %.
Unless otherwise specified, the ambient temperature for testing should be between 16 °C and 32 °C
but if any temperatu
...