FprEN ISO 24442

osmetics - Sun protection test methods - In vivo determination of sunscreen UVA protection (ISO/FDIS 24442:2022)

This document specifies a method for the in vivo determination of UVA protection factor (UVAPF) 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 UVA radiation induced by solar ultraviolet rays.

Kosmetik - Prüfverfahren für Sonnenschutzmittel - In-vivo-Bestimmung des UVA-Sonnenschutzes (ISO/FDIS 24442:2022)

Dieses Dokument legt ein Verfahren zur In-vivo-Bestimmung des UVA-Schutzfaktors (UVASF) von Sonnen-schutzmitteln fest. Es ist anzuwenden für Produkte, die Komponenten enthalten, die in der Lage sind, ultraviolette (UV-)Strahlen zu absorbieren, zu reflektieren oder zu streuen, und die dafür vorgesehen sind, mit der menschlichen Haut in Kontakt gebracht zu werden.
Dieses Dokument dient als eine Basis für die Bewertung von Sonnenschutzmitteln zum Schutz der menschlichen Haut gegen durch ultraviolette Sonnenstrahlen induzierte UVA-Strahlung.

Cosmétiques - Méthodes d’essai de protection solaire - Détermination in vivo de la protection UVA d’un produit de protection solaire (ISO/FDIS 24442:2022)

Le présent document spécifie une méthode de détermination in vivo du facteur de protection contre les UVA (FPUVA) des produits de protection solaire. Il peut s’appliquer à des produits qui contiennent tout composant pouvant absorber, refléter 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 de protection solaire destinés à la protection de la peau humaine contre les rayonnements UVA induits par les rayons ultraviolets solaires.

Kozmetika - Metode za preskušanje zaščite pred soncem - Določevanje zaščitnega faktorja UVA in vivo (ISO/DIS 24442:2021)

General Information

• Status: Not Published
• ICS: 71.100.70 - Cosmetics. Toiletries
• Technical Committee: CEN/TC 392 - Cosmetics
• Ref Project: kSIST FprEN ISO 24442:2022 - Cosmetics - Sun protection test methods - In vivo determination of sunscreen UVA protection (ISO/FDIS 24442:2022)

RELATIONS

• Revised: EN ISO 24442:2011 - Cosmetics - Sun protection test methods - In vivo determination of sunscreen UVA protection (ISO 24442:2011)
• Effective Date: 04-Sep-2019

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 24442:2021
01-april-2021
Kozmetika - Preskusne metode za zaščito pred soncem - Določevanje zaščitnega
faktorja UVA in vivo (ISO/DIS 24442:2021)
Cosmetics - Sun protection test methods - In vivo determination of sunscreen UVA
protection (ISO/DIS 24442:2021)
Kosmetik - Prüfverfahren für Sonnenschutzmittel - In-vivo-Bestimmung des UVA-
Sonnenschutzes (ISO/DIS 24442:2021)

Cosmétique -- Méthodes d'évaluation de la protection solaire -- Détermination in vivo de

la protection UVA (ISO/DIS 24442:2021)
Ta slovenski standard je istoveten z: prEN ISO 24442
ICS:
71.100.70 Kozmetika. Toaletni Cosmetics. Toiletries
pripomočki
oSIST prEN ISO 24442:2021 en,fr,de

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

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oSIST prEN ISO 24442:2021
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oSIST prEN ISO 24442:2021
DRAFT INTERNATIONAL STANDARD
ISO/DIS 24442
ISO/TC 217 Secretariat: ISIRI
Voting begins on: Voting terminates on:
2021-02-22 2021-05-17
Cosmetics — Sun protection test methods — In vivo
determination of sunscreen UVA protection

Cosmétique — Méthodes d'évaluation de la protection solaire — Détermination in vivo de la protection UVA

ICS: 71.100.70
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 24442:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2021
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oSIST prEN ISO 24442:2021
ISO/DIS 24442:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

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
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Published in Switzerland
ii © ISO 2021 – All rights reserved
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oSIST prEN ISO 24442:2021
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Contents Page

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

Introduction ................................................................................................................................................................................................................................vi

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 ............................................................................................................................ 3

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 .................................................................................... 4

6.1 General ........................................................................................................................................................................................................... 4

6.2 Quality of ultraviolet radiation .................................................................................................................................................. 4

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 .......................................................................................................................................................... 5

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 ................................................................................................................................................................................................. 7

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

8.1 General ........................................................................................................................................................................................................... 8

8.2 Reference standard to be used .................................................................................................................................................. 8

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

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

9.2 Test conditions ........................................................................................................................................................................................ 9

9.3 Position of the test subjects ......................................................................................................................................................... 9

9.4 Product application ............................................................................................................................................................................. 9

9.5 UV exposure ............................................................................................................................................................................................13

9.5.1 Provisional MPPDD ...................................................................................................................................................

iu 13

9.5.2 Estimated MPPDD ......................................................................................................................................................

iu 13

9.5.3 Incremental progression of UV dose ...........................................................................................................13

9.6 Product removal .................................................................................................................................................................................13

9.7 Procedure for MPPDD assessment .....................................................................................................................................14

9.7.1 General...................................................................................................................................................................................14

9.7.2 Time of assessment of MPPDD .........................................................................................................................14

9.7.3 Grading scale for the MPPDD s .........................................................................................................................14

9.7.4 Erythema responses ..................................................................................................................................................14

9.7.5 Data rejection criteria ........................................................................................................................................... ....15

9.7.6 Test Failure Criteria ....................................................................................................................................................15

9.7.7 Expression of MPPDDs ............................................................................................................................................15

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

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

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10.2 Calculation of product UVAPF .................................................................................................................................................16

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

10.4 Validation of the test .......................................................................................................................................................................16

11 Test report ................................................................................................................................................................................................................16

11.1 Overview ...................................................................................................................................................................................................16

11.2 General Information ........................................................................................................................................................................17

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

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

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

Annex B (normative) Definition of the source of UVA radiation ...........................................................................................21

Annex C (normative) UVAPF reference sunscreens formulations ......................................................................................24

Annex D (normative) Calculations and statistics .................................................................................................................................37

Annex E (normative) Colourimetric determination of skin colour typing ................................................................43

Annex F (informative) Visual Guidance For PPD Grading ............................................................................................................45

Annex G (informative) Sample Report Form .............................................................................................................................................52

Bibliography .............................................................................................................................................................................................................................56

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oSIST prEN ISO 24442:2021
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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 on 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 the following

URL: 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 24442:2011), which has been technically

revised.
The main changes compared to the previous edition are as follows:
— Revision in accordance with revision of relevant ISO Standard, ISO 24444.
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oSIST prEN ISO 24442:2021
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Introduction

This International Standard specifies the procedure to determine the Ultraviolet A Protection

Factor (UVAPF) of a sunscreen product using the persistent pigment darkening method according to

[1]

the principles recommended by the Japan Cosmetic Industry Association (JCIA) in 1995 . The outcome

of this test method can be used to determine the UVA classification of topical sunscreen products

according to local regulatory requirements.

Topical sunscreen products are primarily rated and labelled according to their ability to protect against

sunburn, using a test method to determine the in vivo Sun Protection Factor (see ISO 24444). This rating

evaluates filtration of sunburn generating radiation across the electromagnetic UV spectrum (290 nm

to 400 nm). However, knowledge of the Sun Protection Factor (SPF) rating does not provide explicit

information on the magnitude of the protection provided specifically in the UVA range of the spectrum

(320 nm to 400 nm), as it is possible to have high SPF products with very modest UVA protection

(e.g. SPF 50 with a UVA protection factor (UVAPF) of only 3 to 4). There is demand among medical

professionals, as well as knowledgeable consumers, to have fuller information on the UVA protection

provided by their sunscreen product, in addition to the SPF, in order to make a more informed choice of

product, providing a more balanced and broader-spectrum protection. Moreover, there also a demand

to prevent UVA-induced darkening of the skin from a cultural point of view even without sunburn.

Thus, persistent pigment darkening (PPD) was selected as an endpoint relevant to UVA. Although PPD

[2]

reflects merely photo-polymerization of melanin monomers , it is evaluated as a representative of

the biological reactions. The UVAPF value of a product provides information on the magnitude of the

[3] [4] [5]

protection provided explicitly in the UVA portion of the spectrum, independent of the SPF values .

The test method outlined in this International Standard is derived primarily from the UVAPF test

methods as developed by the JCIA. Modifications have been made to attempt to be in line with updated

International Standards for determination of sun protection factor without changing the integrity of

the fundamental underlying principles of the test method.
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oSIST prEN ISO 24442:2021
DRAFT INTERNATIONAL STANDARD ISO/DIS 24442:2021(E)
Cosmetics — Sun protection test methods — In vivo
determination of sunscreen UVA protection
1 Scope

This International Standard specifies a method for the in vivo determination of UVA protection factor

(UVAPF) of sunscreen products. This International standard 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.

It provides a basis for the evaluation of sunscreen products for the protection of human skin against

UVA radiation induced by solar ultraviolet rays.
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 24442:2012, Cosmetics — Sun protection test method — In vivo determination of sunscreen UVA

[6]
protection

ISO 24444:2019, Cosmetics — Sun protection test methods — In vivo determination of the sun protection

[7]
factor (SPF)
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.
3.2
erythema
reddening of the skin caused by UV radiation
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3.3
persistent pigment darkening
PPD
skin darkening that persists more than 2 h after the end of UVA exposure
3.4
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 and other

ultraviolet induced damage
3.5
minimal persistent pigment darkening dose
MPPDD

lowest Ultraviolet A (UVA) dose that produces the first perceptible unambiguous persistent pigment

darkening response with defined borders appearing over most of the field of UVA exposure, observed

between 2 h and 24 h after the end of the UVA exposure
3.5.1
MPPDD
MPPDD on unprotected skin
3.5.1.1
MPPDD
MPPDD of an individual subjected on unprotected skin
3.5.2
MPPDD
MPPDD on product protected skin
3.5.2.1
MPPDD
MPPDD of an individual subjected on protected skin
3.6
individual UVA protection factor
UVAPF

ratio of the individual minimal PPD dose on product protected skin (MPPDD ) to the individual minimal

PPD dose on unprotected skin (MPPDD ) of the same subject:
MPPDD
UVAPF =
MPPDD
Note 1 to entry: UVAPF is expressed to one decimal place by truncation.
3.7
UVA protection factor of a product: UVAPF

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

Note 1 to entry: UVAPF is expressed to one decimal place by truncation.
3.8
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.

3.9
test site

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

MPPDD
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3.10
exposure sub-sites
areas of skin that are exposed to UV-irradiation within a test site
3.11
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 UVAPF test method is analogous to the test method used to determine the SPF of a sunscreen

product. However, it utilizes only the UVA portion of the xenon arc lamp solar simulator of defined and

known output to determine the protection provided by sunscreen products on human skin in the UVA

portion of the spectrum.

The UVAPF test method uses PPD responses of the skin as the end point for evaluating transmitted UVA

radiation.
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 UVA radiation 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 UVAPF reference sunscreen formulation, which is used for validation

of the procedure.

To determine the UVAPF, incremental series of PPD responses are induced on a number of small

sub-sites on the skin. These responses are visually assessed for presence of PPD 2 to 24 h after UVA

radiation, by the judgment of a trained and competent evaluator.

The MPPDD and the MPPDD shall be determined on the same subject on the same day. An UVAPF for

iu ip i

each subject tested is calculated as the ratio of MPPDD divide by MPPDD , as in the formula given in

ip iu
item 3.6

The UVAPF is the arithmetic mean of all valid UVAPF 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 set out in Annex A.
5.1.2 Skin colour of the test subjects

Test subjects included in the UVAPF test shall have an ITA° value between 18° and 43° by colourimetric

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

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

tone with no variation in ITA° greater than 5° from each other or the MPPDD test area.

5.1.3 Age restriction

Test subjects below the locally regulated age of consent or older than 70 years shall not be included in

the UVAPF test panel.
5.1.4 Frequency of participation in tests

Subjects may participate in a test provided that at least 8 weeks have elapsed since they participated

in a previous UV exposure study (i.e. SPF, UVAPF, photoallergy, phototoxicity test), and all skin tanned

marks from that previous test have cleared from the test sites on the back and are no longer visible.

5.1.5 Ethics and consent
[8]

All testing shall be done in accordance with the Declaration of Helsinki and national regulations

regarding human studies should also be taken into account.

Informed, written (signature) consent shall be obtained from all test subjects and retained.

5.2 Number of test subjects

The minimum number of valid UVAPF results shall be 10 and the maximum number of valid UVAPF

i i

results shall be 20. In order to achieve between 10 and 20 valid results, a maximum of five individual

invalid results may be excluded from the calculation of the mean UVAPF. For the test to be considered

valid for the first 10 subjects, the resulting range of the 95 % CI of the mean shall be within ± 17 %.

Consequently the actual number of test subjects used will fall between a minimum of 10 and a maximum

of 25 subjects (i.e. a maximum of 20 valid results plus 5 rejected invalid results).

Results may only be declared invalid and excluded from the calculation of the mean UVAPF according

to 9.5.3 or because of non-compliance with the related protocol.

In order to determine the number of test subjects, the 95 % confidence interval (95 % CI) on the

mean UVAPF shall be taken into account. A minimum of 10 subjects shall be tested. The test shall be

considered valid for the first 10 subjects if the resulting range of the 95 % CI of the mean UVAPF shall be

within ± 17 % of the mean UVAPF. If it is not within ± 17 % of the mean UVAPF, the number of subjects

shall be increased stepwise from the minimum number of 10 until the 95 % CI statistical criterion is

met (up to a maximum of 20 valid results from a maximum of 25 subjects tested). If the statistical

criterion has not been met after 20 valid results from a maximum of 25 subjects, then the test shall be

rejected. For details on statistical definitions, sequential procedure and calculations, refer to Annex D.

6 Apparatus and materials— Source of ultraviolet radiation
6.1 General
The artificial light source used shall comply with the source spect
...