SIST EN ISO 24444:2020

Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) (ISO 24444:2019)

This standard specifies a method for the in vivo determination of the sun protectionfactor (SPF) of sunscreen products. It is applicable to products that containany component able to absorb, reflect or scatter ultraviolet (UV) rays and whichare intended to be placed in contact with human skin.This document provides abasis for the evaluation of sunscreen products for the protection of human skinagainst erythema induced by solar ultraviolet rays.

Kosmetik - Untersuchungsverfahren für Sonnenschutzmittel - In-vivo-Bestimmung des Sonnenschutzfaktors (SSF) (ISO 24444:2019)

Dieses Dokument legt ein Verfahren zur In vivo Bestimmung des Sonnenschutzfaktors (SSF) von Sonnen-schutzmitteln fest. Es gilt für Erzeugnisse, welche jegliche Komponenten beinhalten, die ultraviolette (UV )Strahlen absorbieren, reflektieren oder streuen können und dazu bestimmt sind, mit der menschlichen Haut in Kontakt gebracht zu werden.
Dieses Dokument dient als Basis für die Bewertung von Sonnenschutzmitteln zum Schutz der menschlichen Haut vor einem Erythem, das durch ultraviolette Sonnenstrahlen induziert wird.

Cosmétiques - Méthodes d'essai de protection solaire - Détermination in vivo du facteur de protection solaire (FPS (ISO 24444:2019)

Le présent document spécifie une méthode de détermination in vivo du Facteur de Protection Solaire (FPS) des produits solaires. Il peut s'appliquer à des produits qui contiennent tout composant pouvant absorber, réfléchir ou diffuser les rayons ultraviolets (UV) et qui sont destinés à être mis en contact avec la peau humaine.
Le présent document fournit une base pour l'évaluation des produits solaires destinés à la protection de la peau humaine contre un érythème ou un coup de soleil induits par les rayons ultraviolets solaires.

Kozmetika - Preskusne metode za zaščito pred soncem - Določevanje faktorja zaščite pred soncem (SPF) in vivo (ISO 24444:2019)

Ta standard določa metodo za določevanje faktorja zaščite pred soncem (SPF) in vivo sredstev za zaščito kože pred soncem. Uporablja se za izdelke, ki vsebujejo katero koli sestavino za vpijanje, odbijanje ali razpršitev ultravijoličnih žarkov in so namenjeni nanosu na človeško kožo. Ta dokument zagotavlja podlago za vrednotenje sredstev za zaščito pred soncem, ki ščitijo človeško kožo pred pordelostjo zaradi ultravijoličnih sončnih žarkov.

General Information

• Status: Published
• Public Enquiry End Date: 04-Jun-2019
• Publication Date: 04-Feb-2020
• ICS: 71.100.70 - Cosmetics. Toiletries
• Technical Committee: KDS - Cosmetics, chemical disinfectants and surface active agents
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 17-Jan-2020
• Due Date: 23-Mar-2020
• Completion Date: 05-Feb-2020
• Mandate: M/389 - Standardisation mandate assigned to CEN concerning methods for testing efficacy of suncreen products
• Ref Project: EN ISO 24444:2020 - Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) (ISO 24444:2019)

Relations

• Replaces: SIST EN ISO 24444:2011 - Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) (ISO 24444:2010)
• Effective Date: 01-Mar-2020
• Amended By: SIST EN ISO 24444:2020/A1:2022 - Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) - Amendment 1 (ISO 24444:2019/Amd 1:2022)
• Effective Date: 01-Sep-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 24444:2020
01-marec-2020
Nadomešča:
SIST EN ISO 24444:2011
Kozmetika - Preskusne metode za zaščito pred soncem - Določevanje faktorja
zaščite pred soncem (SPF) in vivo (ISO 24444:2019)

Cosmetics - Sun protection test methods - In vivo determination of the sun protection

factor (SPF) (ISO 24444:2019)

Kosmetik - Untersuchungsverfahren für Sonnenschutzmittel - In-vivo-Bestimmung des

Sonnenschutzfaktors (SSF) (ISO 24444:2019)

Cosmétiques - Méthodes d'essai de protection solaire - Détermination in vivo du facteur

de protection solaire (FPS (ISO 24444:2019)
Ta slovenski standard je istoveten z: EN ISO 24444:2020
ICS:
71.100.70 Kozmetika. Toaletni Cosmetics. Toiletries
pripomočki
SIST EN ISO 24444:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 24444:2020
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SIST EN ISO 24444:2020
EN ISO 24444
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2020
EUROPÄISCHE NORM
ICS 71.100.70 Supersedes EN ISO 24444:2010
English Version
Cosmetics - Sun protection test methods - In vivo
determination of the sun protection factor (SPF) (ISO
24444:2019)

Cosmétiques - Méthodes d'essai de protection solaire - Kosmetik - Untersuchungsverfahren für

Détermination in vivo du facteur de protection solaire Sonnenschutzmittel - In-vivo-Bestimmung des

(FPS) (ISO 24444:2019) Sonnenschutzfaktors (SSF) (ISO 24444:2019)
This European Standard was approved by CEN on 9 December 2019.

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 24444:2020 E

worldwide for CEN national Members.
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SIST EN ISO 24444:2020
EN ISO 24444:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 24444:2020
EN ISO 24444:2020 (E)
European foreword

This document (EN ISO 24444:2020) has been prepared by Technical Committee ISO/TC 217

"Cosmetics" in collaboration with Technical Committee CEN/TC 392 “Cosmetics” 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 July 2020, and conflicting national standards shall be

withdrawn at the latest by July 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.

This document supersedes EN ISO 24444:2010.

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association.

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 24444:2019 has been approved by CEN as EN ISO 24444:2020 without any modification.

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SIST EN ISO 24444:2020
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SIST EN ISO 24444:2020
INTERNATIONAL ISO
STANDARD 24444
Second edition
2019-12
Cosmetics — Sun protection test
methods — In vivo determination of
the sun protection factor (SPF)
Cosmétiques — Méthodes d'essai de protection solaire —
Détermination in vivo du facteur de protection solaire (FPS)
Reference number
ISO 24444:2019(E)
ISO 2019
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SIST EN ISO 24444:2020
ISO 24444:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

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 2019 – All rights reserved
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SIST EN ISO 24444:2020
ISO 24444:2019(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ..............................................................................................................................................................................................................................vii

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 General principle ................................................................................................................................................................................................. 3

5 Test subjects .............................................................................................................................................................................................................. 3

5.1 Selection of the test subjects ....................................................................................................................................................... 3

5.1.1 General...................................................................................................................................................................................... 3

5.1.2 Skin colour of the test subjects ............................................................................................................................ 4

5.1.3 Age restriction.................................................................................................................................................................... 4

5.1.4 Frequency of participation in tests .................................................................................................................. 4

5.1.5 Ethics and consent.......................................................................................................................................................... 4

5.2 Number of test subjects ................................................................................................................................................................... 4

6 Apparatus and materials — Source of ultraviolet radiation ................................................................................... 5

6.1 General ........................................................................................................................................................................................................... 5

6.2 Quality of ultraviolet radiation .................................................................................................................................................. 5

6.3 Total irradiance (UV, visible and near infrared rays) ............................................................................................. 5

6.4 Uniformity of beam ............................................................................................................................................................................. 5

6.4.1 General...................................................................................................................................................................................... 5

6.4.2 Film densitometry .......................................................................................................................................................... 6

6.4.3 UV sensor ............................................................................................................................................................................... 6

6.4.4 Large beam source ......................................................................................................................................................... 6

6.4.5 Small beam source.......................................................................................................................................................... 6

7 Maintenance and monitoring the UV solar simulator output ................................................................................ 7

7.1 Spectroradiometry ............................................................................................................................................................................... 7

7.2 Radiometry ................................................................................................................................................................................................. 8

8 Reference sunscreen formulations ................................................................................................................................................... 9

8.1 General ........................................................................................................................................................................................................... 9

8.2 Reference standard to be used .................................................................................................................................................. 9

9 Procedure..................................................................................................................................................................................................................... 9

9.1 Main steps ................................................................................................................................................................................................... 9

9.2 Test conditions .....................................................................................................................................................................................10

9.3 Position of the test subjects ......................................................................................................................................................10

9.4 Product application ..........................................................................................................................................................................10

9.5 Procedure for MED assessment ......... ....................................................................................................................................14

9.5.1 General...................................................................................................................................................................................14

9.5.2 Time of assessment of MED ................................................................................................................................14

9.5.3 Data rejection criteria ........................................................................................................................................... ....15

9.5.4 Test failure criteria ......................................................................................................................................................16

9.5.5 Expression of MEDs ........................................................................................................................................... .........16

10 Calculation of the sun protection factor and statistics ..............................................................................................16

10.1 Calculation of the individual SPF (SPF ) .........................................................................................................................16

10.2 Calculation of product SPF .........................................................................................................................................................16

10.3 Statistical criterion ...........................................................................................................................................................................16

10.4 Validation of the test .......................................................................................................................................................................17

11 Test report ................................................................................................................................................................................................................17

11.1 Overview ...................................................................................................................................................................................................17

11.2 General information ........................................................................................................................................................................17

11.3 Data in tabular form for each test subject ....................................................................................................................17

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SIST EN ISO 24444:2020
ISO 24444:2019(E)

11.4 Statistics for the test products ................................................................................................................................................18

Annex A (normative) Selection criteria for the test subjects ...................................................................................................19

Annex B (normative) Definition of the UV solar simulator output ....................................................................................21

Annex C (normative) SPF reference sunscreen formulations .................................................................................................28

Annex D (normative) Calculations and statistics .................................................................................................................................41

Annex E (normative) Colourimetric determination of skin colour typing and prediction

of the minimal erythemal dose (MED) without UV exposure .............................................................................47

Annex F (informative) Visual guidance for erythema grading ...............................................................................................51

Annex G (Normative) Sample report form ..................................................................................................................................................55

Bibliography .............................................................................................................................................................................................................................59

iv © ISO 2019 – All rights reserved
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SIST EN ISO 24444:2020
ISO 24444:2019(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 Committee ISO/TC 217, Cosmetics.

This second edition cancels and replaces the first edition (ISO 24444:2010), which has been technically

revised.
The main changes compared to the previous edition are as follows.

— The definition of the minimal erythema response (MED) criteria has been revised.

— The choice of eligible test subjects is now based solely on individual typology angle (ITA°) with a

requirement for the average ITA° for the test panel to be within the range 41° to 55°, with a minimum

of three subjects within two of the three ITA° ranges.

— The ITA° is used to define the range of unprotected MED doses for the provisional or the test day

unprotected MED determination (if no provisional MEDu determination is made).

— Three new reference standard sunscreens have been validated and added to the method to validate

SPF test panels for products with SPF equal to 25 or higher (P5, P6 and P8).

— New test methods are provided to determine the uniformity of the beam of both large and small beam

size solar simulators. A requirement for uniformity greater than or equal to 90 % has been added.

— Sunscreen application procedures have been described in greater detail.

— An informative Annex F has been added with photographic examples of erythema responses with

guidelines for grading.

— The reporting tables in Annex G) and the requirements in Clause 11 have modified to provide more

complete information on the results of the testing.
— The bibliography has been updated.
© ISO 2019 – All rights reserved v
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SIST EN ISO 24444:2020
ISO 24444:2019(E)

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.
vi © ISO 2019 – All rights reserved
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SIST EN ISO 24444:2020
ISO 24444:2019(E)
Introduction

The level of sun protection provided by sunscreen products has traditionally been estimated using the

sun protection factor or SPF test, which uses the erythemal response of the skin to ultraviolet (UV)

radiation. The SPF is a ratio calculated from the energies required to induce a minimum erythemal

response with and without sunscreen product applied to the skin of human test subjects. It uses

ultraviolet radiation usually from an artificial source.
[1]-[3]
Different standard methods are available and described in ISO/TR 26369 .

Since the publication of the first version of this document, harmonization has been achieved in many

member countries. The objective of this updated version is to further improve reproducibility between

test sites, so as to obtain the same SPF value.
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SIST EN ISO 24444:2020
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SIST EN ISO 24444:2020
INTERNATIONAL STANDARD ISO 24444:2019(E)
Cosmetics — Sun protection test methods — In vivo
determination of the sun protection factor (SPF)
1 Scope

This document specifies a method for the in vivo determination of the sun protection factor (SPF) of

sunscreen products. It is applicable to products that contain any component able to absorb, reflect or

scatter ultraviolet (UV) rays and which are intended to be placed in contact with human skin.

This document provides a basis for the evaluation of sunscreen products for the protection of human

skin against erythema induced by solar ultraviolet rays.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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/
3.1
ultraviolet radiation
UVR
electromagnetic radiation in the range of 290 nm to 400 nm
3.1.1
ultraviolet B
UVB
electromagnetic radiation in the range of 290 nm to 320 nm
3.1.2
ultraviolet A
UVA
electromagnetic radiation in the range of 320 nm to 400 nm
Note 1 to entry: UVA II = 320 nm to 340 nm; UVA I = 340 nm to 400 nm.
3.1.3
erythemal effective irradiance

radiometric quantity derived by multiplying the spectral irradiance E(λ) of the solar simulator with

[4]

the erythema action spectrum s (λ) at each wavelength λ and integrating over wavelength range of

290 nm to 400 nm
400
EE= ()λλsd() λ unit: W/m (eff.)
er er
290
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SIST EN ISO 24444:2020
ISO 24444:2019(E)
3.1.4
erythemal effective radiant exposure
erythemal dose

radiometric quantity defined as time integral of erythemal effective irradiance E (t)

HE= ()tdt unit: J/m (eff.)
er er
3.2
erythema
reddening of the skin caused by UV radiation
3.3
sunscreen products

products containing any component able to absorb, reflect or scatter UV rays, which are intended to be

placed on the surface of human skin with the purpose of protecting against erythema (3.2) and other

ultraviolet induced damage
3.4
minimal erythemal dose
MED

lowest erythemal effective radiant exposure (H ) (3.1.4) that produces the first perceptible unambiguous

erythema with defined borders appearing over more than 50 % of UV exposure subsite, 16 h to 24 h

after UV exposure

Note 1 to entry: Annex F contains visual references and guidance for the acceptable MED appearance.

3.4.1
MED
minimal erythemal dose on unprotected skin
3.4.1.1
MED
minimal erythemal dose of an individual subject on unprotected skin
3.4.2
MED
minimal erythemal dose on product protected skin
3.4.2.1
MED
minimal erythemal dose of an individual subject on protected skin
3.5
individual sun protection factor
SPF

ratio of the individual minimal erythemal dose on product protected skin (MED ) to the (individual)

minimal erythemal dose on unprotected skin (MED ) of the same subject:
MED
SPF =
MED
Note 1 to entry: SPF is expressed to one decimal place by truncation.
3.6
sun protection factor of a product
SPF

arithmetic mean of all valid individual SPF values obtained from all subjects in the test

Note 1 to entry: SPF is expressed to one decimal place by truncation.
2 © ISO 2019 – All rights reserved
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SIST EN ISO 24444:2020
ISO 24444:2019(E)
3.7
test area
area for testing on the back between the scapula line and the waist

Note 1 to entry: Skeletal protrusions and extreme areas of curvature should be avoided.

3.8
test site

area of the skin where a product is applied or the site used for the determination of the unprotected MED

3.9
exposure sub-sites
areas of skin that are exposed to UV-irradiation within a test site
3.10
individual typology angle
ITA°

value characterizing the skin colour of the subject as measured by a skin contact reflectance

spectrophotometer or skin colourimeter

Note 1 to entry: Refer to Annex E for the detailed requirements of the equipment/measurement.

4 General principle

The SPF test method is a laboratory method that utilizes a xenon arc lamp solar simulator (or equivalent)

of defined and known output to determine the protection provided by sunscreen products on human

skin against erythema induced by solar ultraviolet rays.
The test shall be restricted to the area of the back of selected human subjects.

A section of each subject’s skin is exposed to ultraviolet light without any protection while another

(different) section is exposed after application of the sunscreen product under test. One further section

is exposed after application of an SPF reference sunscreen formulation, which is used for validation of

the procedure.

To determine the sun protection factor, incremental series of delayed erythemal responses are induced

on a number of small sub-sites on the skin. These responses are visually assessed for presence of

erythema 16 h to 24 h after UV radiation, by the judgment of a trained and competent evaluator.

The individual minimal erythemal dose for unprotected skin (MED ) and the individual MED obtained

after application of a sunscreen product (MED ) shall be determined on the same subject on the same

day. An individual sun protection factor (SPF ) for each subject tested is calculated as the ratio of

individual MED on product protected skin divided by the individual MED on unprotected skin, as in the

formula given in 3.5.

The sun protection factor for the product (SPF) is the arithmetic mean of all valid SPF results from

each subject in the test expressed to one decimal place.
5 Test subjects
5.1 Selection of the test subjects
5.1.1 General

There are strict requirements governing the inclusion and non-inclusion of test subjects which should

be adhered to. The criteria shall be as set out in Annex A.
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SIST EN ISO 24444:2020
ISO 24444:2019(E)
5.1.2 Skin colour of the test subjects

Test subjects included in the SPF test shall have an ITA° value of at least 28° by colourimetric methods

(see Annexes A and E) and be untanned on the test area.

The average of the subjects making up a test panel shall have an ITA° between 41° and 55°. When

possible, there should be subjects with ITA°s in each of the three ITA° bands, 28° to 40°, 41° to 55°, and

>56°. Where this is not possible, there shall be at least three individuals in each of two of the three ITA°

bands described in the previous sentence.

A trained and competent scientist or technician should examine each subject to ensure that there is no

condition which might put the subject at risk and that the outcome of the test cannot be compromised

by adverse skin conditions such as sun damage, pigmentation marks and previous history of abnormal

response to the sun (see Annex A).

The test sites intended for UV exposure shall be free from blemishes and hair, and have an even colour

tone with no va
...