SIST EN ISO 24443:2022
(Main)Cosmetics - Determination of sunscreen UVA photoprotection in vitro (ISO 24443:2021, Corrected version 2022-02)
Cosmetics - Determination of sunscreen UVA photoprotection in vitro (ISO 24443:2021, Corrected version 2022-02)
This document specifies an in vitro procedure to characterize the UVA protection of sunscreen
products. Specifications are given to enable determination of the spectral absorbance characteristics of
UVA protection in a reproducible manner.
In order to determine relevant UVA protection parameters, the method has been created to provide an
UV spectral absorbance curve from which a number of calculations and evaluations can be undertaken.
These include calculation of the Ultraviolet-A protection factor (UVA-PF) [correlating with in vivo
UVA-PF from the persistent pigment darkening (PPD) testing procedure], critical wavelength and UVA
absorbance proportionality. These computations are optional and relate to local sunscreen product
labelling requirements. This method relies on the use of static in vivo SPF results for scaling the UV
absorbance curve.
This document is not applicable to powder products such as pressed powder and loose powder products.
Kosmetische Mittel - In-vitro-Bestimmung des UVA Schutzes von Sonnenschutzmitteln (ISO 24443:2021, korrigierte Fassung 2022-02)
Dieses Dokument legt ein In vitro Verfahren zur Charakterisierung des UVA Schutzes von Sonnenschutz¬mitteln fest. Es werden Spezifikationen angegeben, die eine reproduzierbare Bestimmung der spektralen Extinktionseigenschaften des UVA Schutzes ermöglichen.
Zur Bestimmung von für den UVA Schutz relevanten Kenngrößen wurde ein Verfahren zur Aufstellung einer Kurve der spektralen Extinktion im UV Bereich entwickelt, auf dessen Grundlage eine Reihe von Berechnungen und Bewertungen vorgenommen werden können. Diese umfassen die Berechnung des UVA Schutzfaktors (UVA PF) [korreliert mit dem In vivo UVA Schutzfaktor aus dem Persistent-Pigment-Darkening (PPD) Prüfverfahren], der kritischen Wellenlänge und des UVA-Extinktionsverhältnisses. Diese Berechnungen sind optional und beziehen sich auf die örtlichen Anforderungen an die Kennzeichnung von Sonnenschutzmitteln. Dieses Verfahren basiert auf der Verwendung von statischen In vivo SPF Ergebnissen für die Skalierung der UV Extinktionskurve.
Dieses Dokument ist nicht anwendbar für pulverförmige Produkte, die z. B. gepresst oder lose vorliegen.
Cosmétiques - Détermination in vitro de la photoprotection UVA (ISO 24443:2021, Version corrigée 2022-02)
Le présent document spécifie un mode opératoire in vitro pour caractériser la protection UVA apportée par les produits de protection solaire. Des spécifications sont fournies pour permettre de déterminer les caractéristiques d’absorbance spectrale de la protection UVA de façon reproductible.
Afin de déterminer les paramètres de protection UVA pertinents, la méthode a été mise au point de sorte à fournir une courbe d’absorbance spectrale UV à partir de laquelle des calculs et des évaluations peuvent être effectués. Ces calculs comprennent le calcul du facteur de protection contre les ultraviolets A (FPUVA) [corrélé au FPUVA in vivo du mode opératoire d’essai de pigmentation persistante (PPD)], de la longueur d’onde critique et de la proportionnalité de l’absorbance des UVA. Ces calculs sont facultatifs et sont liés aux exigences d’étiquetage locales des produits de protection solaire. Cette méthode repose sur les résultats du FPS in vivo statique pour élaborer la courbe d’absorbance des UV.
Le présent document n’est pas applicable aux produits sous forme de poudre tels que les produits en poudre compacte ou en poudre libre.
Kozmetika - Določevanje zaščitnega faktorja UVA in vitro (ISO 24443:2021, popravljena izdaja 2022-02)
Ta dokument določa postopek in vitro za opredelitev zaščite pred žarki UVA varovalnih sredstev za zaščito kože pred soncem. Podane specifikacije omogočajo določitev lastnosti spektralne absorpcije zaščite pred žarki UVA na ponovljiv način.
Za določitev ustreznih parametrov zaščite pred žarki UVA je bila ustvarjena metoda za zagotovitev krivulje spektralne absorpcije UV, iz katere je mogoče izpeljati številne izračune in ocene.
Slednji vključujejo izračun ultravijoličnega A zaščitnega faktorja (UVA-PF) [ki se navezuje na UVA-PF in vivo iz preskusnega postopka obstojne pigmentacije (PPD)], kritične valovne dolžine in razmerja absorpcije žarkov UVA. Ti izračuni so izbirni in se navezujejo na zahteve glede označevanja izdelkov za zaščito kože pred soncem. Ta metoda temelji na uporabi rezultatov in vivo za statični zaščitni faktor pri določanju merila krivulje absorpcije žarkov UV.
Ta dokument se ne uporablja za izdelke v prahu, kot so na primer pudri v kamnu in prahu.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 24443:2022
01-julij-2022
Nadomešča:
SIST EN ISO 24443:2012
Kozmetika - Določevanje zaščitnega faktorja UVA in vitro (ISO 24443:2021,
popravljena izdaja 2022-02)
Cosmetics - Determination of sunscreen UVA photoprotection in vitro (ISO 24443:2021,
Corrected version 2022-02)
Kosmetische Mittel - In-vitro-Bestimmung des UVA Schutzes von Sonnenschutzmitteln
(ISO 24443:2021, korrigierte Fassung 2022-02)
Cosmétiques - Détermination in vitro de la photoprotection UVA (ISO 24443:2021,
Version corrigée 2022-02)
Ta slovenski standard je istoveten z: EN ISO 24443:2021
ICS:
71.100.70 Kozmetika. Toaletni Cosmetics. Toiletries
pripomočki
SIST EN ISO 24443:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 24443:2022
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SIST EN ISO 24443:2022
EN ISO 24443
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2021
EUROPÄISCHE NORM
ICS 71.100.70 Supersedes EN ISO 24443:2012
English Version
Cosmetics - Determination of sunscreen UVA
photoprotection in vitro (ISO 24443:2021, Corrected
version 2022-02)
Cosmétiques - Détermination in vitro de la Kosmetische Mittel - In-vitro-Bestimmung des UVA
photoprotection UVA (ISO 24443:2021, Version Schutzes von Sonnenschutzmitteln (ISO 24443:2021,
corrigée 2022-02) korrigierte Fassung 2022-02)
This European Standard was approved by CEN on 17 October 2021.
This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 16 March 2022.
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 NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 24443:2021 E
worldwide for CEN national Members.
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SIST EN ISO 24443:2022
EN ISO 24443:2021 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 24443:2022
EN ISO 24443:2021 (E)
European foreword
This document (EN ISO 24443:2021) 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 June 2022, and conflicting national standards shall be
withdrawn at the latest by June 2022.
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 24443:2012.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 24443:2021, Corrected version 2022-02 has been approved by CEN as
EN ISO 24443:2021 without any modification.
3
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SIST EN ISO 24443:2022
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SIST EN ISO 24443:2022
INTERNATIONAL ISO
STANDARD 24443
Second edition
2021-12
Corrected version
2022-02
Cosmetics — Determination of
sunscreen UVA photoprotection in
vitro
Cosmétiques — Détermination in vitro de la photoprotection UVA
Reference number
ISO 24443:2021(E)
© ISO 2021
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SIST EN ISO 24443:2022
ISO 24443:2021(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
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
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
Contents Page
Foreword .iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Symbols and abbreviated terms . 2
4 Principle . 3
5 Apparatus . 3
5.1 Spectrophotometer specifications . 3
5.2 Calibration of the spectrophotometer . 4
5.3 Calibration of the UV exposure source . 4
5.4 Monitoring of the UV exposure source . 5
5.5 Calibration of the UVA radiometer used to monitor the test sample irradiation . 5
5.6 Substrate/plate . 5
6 Test method . 6
6.1 Outline of the test procedure . 6
6.2 Equipment calibration and validation of test plates . 6
6.3 Absorption measurements through the plate . 6
6.4 Sample application . 7
6.5 Absorbance measurements of the product-treated plate . 8
6.6 Number of determinations . 8
6.7 Determination of initial calculated SPF (SPF ), “C” value, initial UVA-PF
in vitro,0
(UVA-PF ), and UV exposure dose . 8
0
6.7.1 Determination of initial in vitro SPF (SPF ) . 8
in vitro,0
6.7.2 Determination of “C” value . 8
6.7.3 Determination of initial UVA protection factor before UV exposure (UVA-
PF ) . 9
0
6.7.4 Determination of the UV exposure dose . 10
6.8 UV exposure of sample plates . 10
6.9 Calculation of UVA-PF of plates after UV exposure of the sample . 10
6.10 Calculation of critical wavelength of plates after UV exposure of the sample . 11
7 Procedure using the spreadsheet in this document .11
8 Product reference sunscreen .12
8.1 Formula S2. 12
8.2 Standard P8 .12
9 Test report .12
Annex A (normative) Calibration of spectrophotometer and plate transmission test .14
Annex B (normative) Radiometer calibration to spectroradiometric irradiance procedure .18
Annex C (normative) Computation values: PPD and erythema action spectra and UVA and
UV‑SSR spectral irradiances .20
Annex D (normative) PMMA substrate plate surface specifications .23
Annex E (normative) Product reference sunscreen formulations .26
Annex F (informative) Statistical calculations .32
Annex G (informative) Definition and examples of valid results/Factor “C” .35
Bibliography .36
iii
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SIST EN ISO 24443:2022
ISO 24443:2021(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, in collaboration with
the European Committee for Standardization (CEN) Technical Committee CEN/TC 392, Cosmetics, in
accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 24443:2012), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— acceptance of moulded and sandblasted PMMA plates, according to specifications described in
Annex D;
2
— product application fitted to 1,2mg/cm for sandblasted plates;
— description of application gesture according to tested products;
— introduction of a new high UVA PF standard P8;
— introduction of critical wavelength calculation;
— calculation of coefficient "C" accepted from in vivo screening SPF, with specific conditions based on
SEM and percentage of variability, and new range proposed from 0,6 to 1,6;
2
— limitation of UVA irradiation dose to 36 J/cm .
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.
This corrected version of ISO 24443:2021 incorporates the following corrections:
— Formulae (2) and (4) have been corrected;
— in 6.7.2, the significance of SEM has been explained;
iv
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
— in A.5.1, the transmission values for sandblasted PMMA plates have been corrected;
— Bibliographic references have been corrected.
v
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
Introduction
This document specifies the procedure to determine the ultraviolet protection factor (UVA-PF) of a
sunscreen product using the in vitro UVA-PF according to the principles recommended by the European
Cosmetic and Perfumery Association (COLIPA) in 2011. 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-PF of only 3 to 4). There is a 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 is also a demand to
prevent UVA-induced darkening of the skin from a cultural point of view even without sunburn. The
UVA-PF value of a product provides information on the magnitude of the protection provided explicitly
in the UVA portion of the spectrum, independent of the SPF values.
The test method outlined in this document is derived primarily from the in vitro UVA-PF test method as
developed by COLIPA.
vi
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SIST EN ISO 24443:2022
INTERNATIONAL STANDARD ISO 24443:2021(E)
Cosmetics — Determination of sunscreen UVA
photoprotection in vitro
1 Scope
This document specifies an in vitro procedure to characterize the UVA protection of sunscreen
products. Specifications are given to enable determination of the spectral absorbance characteristics of
UVA protection in a reproducible manner.
In order to determine relevant UVA protection parameters, the method has been created to provide an
UV spectral absorbance curve from which a number of calculations and evaluations can be undertaken.
These include calculation of the Ultraviolet-A protection factor (UVA-PF) [correlating with in vivo
UVA-PF from the persistent pigment darkening (PPD) testing procedure], critical wavelength and UVA
absorbance proportionality. These computations are optional and relate to local sunscreen product
labelling requirements. This method relies on the use of static in vivo SPF results for scaling the UV
absorbance curve.
This document is not applicable to powder products such as pressed powder and loose powder products.
2 Normative references
There are no normative references in this document.
3 Terms, definitions, symbols and abbreviated terms
3.1 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 https:// www .electropedia .org/
3.1.1
UV
ultraviolet radiation
electromagnetic radiation in the range of 290 nm to 400 nm
3.1.2
UVB
ultraviolet B
electromagnetic radiation in the range of 290 nm to 320 nm
3.1.3
UVA
ultraviolet A
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.
1
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
3.1.4
spectral absorbance
ai(λ)
logarithm to base 10 of the reciprocal of the spectral internal transmittance, ai(λ)=−log10 τi(λ)
Note 1 to entry: In the context of this standard the absorption or transmission of sunscreen is used.
3.1.5
irradiance
I
2
fluence rate per unit area, expressed in W/m , for a defined range of wavelengths
Note 1 to entry: From 290 nm to 400 nm for UVA + UV-B irradiance; from 320 nm to 400 nm for UVA irradiance.
3.1.6
spectral irradiance
I(λ)
2
irradiance (3.1.5) per unit wavelength, I(λ), expressed in W/m /nm
Note 1 to entry: Spectral irradiance can refer to PPD testing or SPF testing.
3.1.7
spectrophotometer
equipment for measuring the reflection or transmission properties of a material as a function of
wavelength limited to ultraviolet, visible and short infrared ranges in this document
3.1.8
spectroradiometer
device designed to measure the spectral density of illuminants
3.1.9
radiometer
device for measuring the radiant flux (power) of electromagnetic radiation
3.1.10
product reference sunscreen
reference sunscreen product used to validate the testing procedure
3.1.11
solar simulator
equipment used to simulate the solar irradiance and spectrum
3.1.12
plate
substrate
material to which the test product is to be applied
3.2 Symbols and abbreviated terms
3.2.1
UVA-PF
in vitro ultraviolet A protection factor
in vitro UVA protection factor of a sun protection product against UVA radiation, which can be derived
mathematically with in vitro spectral modelling
3.2.2
SPF
in vitro
in vitro sun protection factor
in vitro protection factor of a sun protection product against erythema-inducing radiation calculated
with spectral modelling
2
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
3.2.3
critical wavelength
CWL
λc
wavelength at which the area under the absorbance curve represents 90 % of the total area under the
curve in the UV region
Note 1 to entry: Calculated from spectral data.
3.2.4
erythema action spectrum
E(λ)
relative effects of individual spectral bands of an exposure source for an erythema response
3.2.5
PPD action spectrum
P(λ)
relative effects of individual spectral bands of an exposure source for a persistent pigment response
4 Principle
The test is based on the assessment of UV-transmittance through a thin film of sunscreen sample spread
on a roughened substrate, before and after exposure to a controlled dose of radiation from a defined UV
exposure source.
Because of several variables that cannot be controlled with typical thin film spectroscopic techniques,
each set of sunscreen transmission data is mathematically adjusted so that the in vitro SPF data yield
the same measured in vivo SPF value that was determined by in vivo testing. As in vivo method can
raise ethical consideration, any alternative SPF method, published as an ISO method, may be used.
Samples are exposed to a specific measured dose of UV radiation to account for the photostability
characteristics of the test product.
The resulting spectral absorbance data have been shown to be a useful representation of both the
width and height of the UVA protection characteristics of the sunscreen product being tested. The
mathematical modelling procedure has been empirically derived to correlate with human in vivo
(persistent pigment darkening) test results.
5 Apparatus
5.1 Spectrophotometer specifications
The spectrophotometer wavelength range shall span the primary waveband of 290 nm to 400 nm. The
wavelength increment step shall be 1 nm.
A spectrophotometer that does not have a monochromator after the test sample should employ a
fluorescence rejection filter.
The spectrophotometer input optics should be designed for diffuse illumination and/or diffuse
collection of the transmitted irradiance through the roughened polymethylmethacrylate (PMMA)
substrate, with and without the sunscreen layer spread on its surface.
The size of the diameter of the entrance port of the spectrophotometer probe shall be smaller than the
size of the light spot to be measured at the sample level (in order to account for stray light).
2
The area of each reading site should be at least 0,5 cm in order to reduce the variability between
readings and to compensate for the lack of uniformity in the product layer.
3
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
The wavelength should be accurate to within 1 nm, as checked using a holmium-doped filter (see
Annex A). The ability of an instrument to accurately measure absorbance is limited by the sensitivity of
the instrument. The minimum required dynamic range for this methodology is 2,2 absorbance units as
determined according to Annex A.
The maximum measured absorbance should be within the dynamic range of the device used. If
the test measurements yield absorbance curves that exceed the determined upper limit of the
spectrophotometer, the product should be re-tested using an instrument with increased sensitivity and
dynamic range.
The lamp in the spectrophotometer that is used to measure the transmittance shall emit continuous
radiation over the range of 290 nm to 400 nm, and the level of irradiance should be sufficiently low, so
that the photostability of the product is not unduly challenged (a xenon lamp is a convenient solution).
2
Therefore, the UV dose during one measurement cycle should not exceed 0,2 J/cm .
NOTE A spectrophotometer is used to measure the absorbance properties of the sunscreen on the test
plates. A spectroradiometer is used to measure the spectral energy distribution and intensity of the UV exposure
source or the spectrophotometer during the absorbance measurement of the sunscreen on the test plate.
Coupled with an UV source, the spectroradiometer can give similar results to a spectrophotometer.
5.2 Calibration of the spectrophotometer
The spectrophotometer shall be validated every month by measurements of reference materials.
A three-fold test is required, as described in Annex A:
— dynamic range of the spectrophotometer;
— linearity test of the spectrophotometer;
— wavelength accuracy test.
5.3 Calibration of the UV exposure source
The spectral irradiance at the exposure plane of the UV exposure source that is used for irradiation
(to take into account any photoinstability) shall be as similar as possible to the irradiance at ground
[5] [6]
level under a standard zenith sun . As defined by COLIPA , the reference standard sun has a total
2 2
irradiance of 51,4 W/m to 63,7 W/m and a UVA to UVB irradiance ratio of 16,9 to 17,5.
Therefore, the UV irradiance shall be within the following acceptance limits (measured at sample
distance).
Table 1 — UV exposure source specifications
UV exposure source specifications as measured with a spectroradiometer
2 2
Total UV irradiance (290 nm to 400 nm) 40 W/m to 200 W/m
a b
Irradiance ratio of UVA to UVB 11-22
a
320 nm to 400 nm.
b
290 nm to 320 nm.
In broad-beam UV-sources, spectra from different locations under the beam shall be recorded over at
least 5 different locations (a location is defined for each plate) in order to account for uniformity.
The uniformity shall be ≥ 90 % as calculated by Formula (1):
U = (1-(max-min)/(X̅)) (1)
4
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SIST EN ISO 24443:2022
ISO 24443:2021(E)
where
U is the uniformity in percentage;
X̅ is the average.
If the uniformity is less than 90 %, then optical components should be adjusted or appropriate
compensation for different irradiance shall be made in the exposure time on each plate.
The UV exposure source device should h
...
SLOVENSKI STANDARD
oSIST prEN ISO 24443:2020
01-junij-2020
Kozmetika - Določevanje zaščitnega faktorja UVA in vitro (ISO/DIS 24443:2020)
Determination of sunscreen UVA photoprotection in vitro (ISO/DIS 24443:2020)
In vitro Bestimmung des UVA-Schutzes von Sonnenschutzmitteln (ISO/DIS 24443:2020)
Détermination in vitro de la photoprotection UVA (ISO/DIS 24443:2020)
Ta slovenski standard je istoveten z: prEN ISO 24443 rev
ICS:
71.100.70 Kozmetika. Toaletni Cosmetics. Toiletries
pripomočki
oSIST prEN ISO 24443:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN ISO 24443:2020
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oSIST prEN ISO 24443:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 24443
ISO/TC 217 Secretariat: ISIRI
Voting begins on: Voting terminates on:
2020-04-30 2020-07-23
Determination of sunscreen UVA photoprotection in vitro
Détermination in vitro de la photoprotection UVA
ICS: 71.100.70
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 3
5.1 UV spectrophotometer specifications . 3
5.2 Calibration of the UV spectrophotometer. 4
5.3 Calibration of the UV exposure source . 4
5.4 Monitoring of the UV exposure source . 4
5.5 Calibration of the UVA radiometer used to monitor the test sample irradiation . 5
5.6 Substrate/plate . 5
6 Test method . 5
6.1 Outline of the test procedure . 5
6.2 Equipment calibration and validation of test plates. 6
6.3 Absorption measurements through the plate . 6
6.4 Sample application . 6
6.5 Absorbance measurements of the product-treated plate . 7
6.6 Number of determinations . 7
6.7 Determination of initial calculated SPF (SPF ), “C” value, initial UVA-PF (UVA-
in vitro
PF ), and UV exposure dose . 7
0
6.7.1 Determination of SPF .
in vitro 7
6.7.2 Determination of “C” value . 8
6.7.3 Determination of initial UVA protection factor before UV exposure (UVA-PF ) . 8
0
6.7.4 Determination of the UV exposure dose. 9
6.8 UV exposure . 9
6.9 Measurement of final adjusted absorbance spectrum . 9
6.10 Calculation of UVA-PF of plates after UV exposure of the sample .10
6.11 Calculation of critical wavelength of plates after UV exposure of the sample .10
7 Procedure using the spreadsheet in this document .10
8 Product reference sunscreen .11
8.1 Formula S2 .11
8.2 Standard P8 .11
9 Test report .12
Annex A (normative) Calibration of UV spectrophotometer and plate transmission test.13
Annex B (normative) Radiometer calibration to spectroradiometric irradiance procedure .17
Annex C (normative) Computation values: PPD and erythema action spectra and UVA and
UV-SSR spectral irradiances .19
Annex D (normative) PMMA test plate surface specifications .22
Annex E (normative) UVA Product reference sunscreen S2 .25
Annex F (informative) Statistical calculations .31
Bibliography .34
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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 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 24443:2012), which has been technically
revised.
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.
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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 in vitro UVAPF according to the principles recommended
by COLIPA in 2011. 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 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. The UVAPF
value of a product provides information on the magnitude of the 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 in vitro UVAPF
test method as developed by COLIPA.
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oSIST prEN ISO 24443:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 24443:2020(E)
Determination of sunscreen UVA photoprotection in vitro
1 Scope
This document specifies an in vitro procedure to characterize the UVA protection of sunscreen products.
Specifications are proposed to enable determination of the spectral absorbance characteristics of UVA
protection in a reproducible manner.
In order to determine relevant UVA protection parameters, the method has been created to provide an
UV spectral absorbance curve from which a number of calculations and evaluations can be undertaken.
Results from this measurement procedure can be used for other computations, as required by local
regulatory authorities. These include calculation of the Ultraviolet-A protection factor (UVA-PF)
[correlating with in vivo UVA-PF from the persistent pigment darkening (PPD) testing procedure],
critical wavelength and UVA absorbance proportionality. These computations are optional and relate
to local sunscreen product labelling requirements. This method relies on the use of static in vivo SPF
results for scaling the UV absorbance curve.
This document is not applicable to powder products such as pressed powder and loose powder products.
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 24444, Cosmetics — Sun protection test methods — In vivo determination of the sun protection
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
in vitro UVA protection factor
UVA-PF
in vitro UVA protection factor of a sun protection product against UVA radiation, which can be derived
mathematically with in vitro spectral modelling
3.2
in vitro protection factor
SPF , protection factor of a sun protection product against erythema-inducing radiation calculated
in vitro
with spectral modelling
3.3
λc
critical wavelength, calculated from spectral data. It corresponds to the wavelength at which the area
under the absorbance curve represents 90 % of the total area under the curve in the UV region
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3.4
[1]
action spectrum for erythema [2].
E(λ)
relative effects of individual spectral bands of an exposure source for an erythema response
3.5
[3]
action spectrum for PPD [4].
P(λ)
relative effects of individual spectral bands of an exposure source for a persistent pigment response
3.6
monochromatic absorbance
A
λ
sunscreen absorbance at wavelength, λ, related to the sunscreen transmittance, T , by
λ
ATλ =−log
()
λ
where transmittance, T , is the fraction of incident irradiance transmitted by the sunscreen film
λ
3.7
irradiance
I
2
fluence rate per unit area, expressed in W/m , for a defined range of wavelengths
EXAMPLE From 290 nm to 400 nm for UVA + UV-B irradiance; from 320 nm to 400 nm for UVA irradiance.
3.8
spectral irradiance for SPF testing or PPD testing
I(λ)
2
irradiance per unit wavelength, I(λ), expressed in W/m /nm
3.9
spectrophotometer
equipment for measuring the reflection or transmission properties of a material as a function of
wavelength limited to ultraviolet, visible and short infrared ranges in this document
3.10
spectroradiometer
device designed to measure the spectral density of illuminants
3.11
radiometer
device for measuring the radiant flux (power) of electromagnetic radiation
3.12
reference product
reference sunscreen product used to validate the testing procedure
3.13
solar simulator
Equipment used to simulate the solar irradiance and spectrum.
3.14
substrate plate
Material to which the test product is to be applied.
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4 Principle
The test is based on the assessment of UV-transmittance through a thin film of sunscreen sample spread
on a roughened substrate, before and after exposure to a controlled dose of radiation from a defined UV
exposure source.
Because of the several variables that cannot be controlled with typical thin film spectroscopic
techniques, each set of sunscreen transmission data is mathematically adjusted so that the in vitro
SPF data yield the same measured in vivo SPF value that was determined by in vivo testing. As in vivo
method could raise ethical consideration, any alternative SPF method, published as an ISO method, may
be used.
Samples are then exposed to a specific measured dose of UV radiation to account for the photostability
characteristics of the test product.
The resulting spectral absorbance data have been shown to be a useful representation of both the
width and height of the UVA protection characteristics of the sunscreen product being tested. The
mathematical modelling procedure has been empirically derived to correlate with human in vivo
(persistent pigment darkening) test results.
5 Apparatus
5.1 UV spectrophotometer specifications
The UV spectrophotometer wavelength range shall span the primary waveband of 290 nm to 400 nm.
The wavelength increment step shall be 1 nm.
A UV spectrophotometer that does not have a monochromator after the test sample should employ a
fluorescence rejection filter.
The UV spectrophotometer input optics should be designed for diffuse illumination and/or diffuse
collection of the transmitted irradiance through the roughened polymethylmethacrylate (PMMA)
substrate, with and without the sunscreen layer spread on its surface.
The size of the diameter of the entrance port of the UV spectrophotometer probe shall be smaller than
the size of the light spot to be measured at the sample level (in order to account for stray light).
2
The area of each reading site should be at least 0,5 cm in order to reduce the variability between
readings and to compensate for the lack of uniformity in the product layer.
The wavelength should be accurate to within 1 nm, as checked using a holmium-doped filter (see Annex
A). The ability of an instrument to accurately measure absorbance is limited by the sensitivity of the
instrument. The minimum required dynamic range for this methodology is 2,2 absorbance units as
determined according to Annex A.
The maximum measured absorbance should be within the dynamic range of the device used. If
the test measurements yield absorbance curves that exceed the determined upper limit of the UV
spectrophotometer, the product should be re-tested using an instrument with increased sensitivity and
dynamic range.
The lamp in the UV spectrophotometer that is used to measure the transmittance shall emit continuous
radiation over the range of 290 nm to 400 nm, and the level of irradiance should be sufficiently low, so
that the photostability of the product is not unduly challenged (a xenon lamp is a convenient solution).
2
Therefore, the UV dose during one measurement cycle should not exceed 0,2 J/cm .
NOTE A UV spectrophotometer is used to measure the absorbance properties of the sunscreen on the test
plates. A spectroradiometer is used to measure the spectral energy distribution and intensity of the UV exposure
source or the UV spectrophotometer during the absorbance measurement of the sunscreen on the test plate.
Coupled with an UV source, the radiometer can give similar results to a spectrophotometer.
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5.2 Calibration of the UV spectrophotometer
The UV spectrophotometer shall be validated every month by measurements of reference materials.
A three-fold test is required, as described in Annex A:
— dynamic range of the UV spectrophotometer;
— linearity test of the UV spectrophotometer;
— wavelength accuracy test.
5.3 Calibration of the UV exposure source
The spectral irradiance at the exposure plane of the UV exposure source that is used for irradiation
(to take into account any photoinstability) shall be as similar as possible to the irradiance at ground
[1] [2]
level under a standard zenith sun. As defined by COLIPA, the reference standard sun has a total
irradiance of 51.4 to 63.7 W/m2 and a UVA to UVB irradiance ratio of 16.9 to 17.5.
Therefore, the UV irradiance shall be within the following acceptance limits (measured at sample
distance).
Table 1 — UV exposure source specifications
UV exposure source specifications as measured with a spectroradiometer
2 2
Total UV irradiance (290 nm to 400 nm) 40 W/m to 200 W/m
a b
Irradiance ratio of UVA to UVB 11-22
a
320 nm to 400 nm.
b
290 nm to 320 nm.
In broad-beam UV-sources, spectra from different locations under the beam shall be recorded over at
least 5 different locations (a location is defined for each plate) in order to account for uniformity.
The uniformity shall be ≥ 90% as calculated by the equation:
(1-(max-min)/(average))% ≥ 90% *
*If the uniformity is less than 90%, then optical components should be adjusted or appropriate
compensation for different irradiance shall be made in the exposure time on each plate.
The UV exposure source device should have the ability to maintain samples within the range of 27 °C
to 32 °C, with intra laboratory temperature ± 2 °C. It is important that the temperature of the sample
itself on the plate shall be measured and not just the surrounding air temperature. Therefore, the
measurement of the temperature shall be on plate level.
To maintain samples at required temperature, a filter system that particularly reduces Infrared
radiation shall be used to achieve the specified temperature range. Cooling trays for the sample plates
or ventilators shall be used to maintain a temperature lower than 32 °C and warming devices to
maintain samples at or above 27 °C.
Measurement to be made using a sensor that is traceable to a national or an international calibration
standard, within the range of use.
5.4 Monitoring of the UV exposure source
The emission of the UV exposure source used for exposure shall be checked for compliance with the
given acceptance limits by a suitably qualified expert (at least) every 12 months, or 2500 hours of lamp
running time. The inspection should be conducted with a spectroradiometer that has been calibrated
against a standard lamp that is traceable to a national or an international calibration standard provided
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by an accredited ISO17025 laboratory. In addition to the spectroradiometric inspection, the intensity of
the UV exposure source used for exposure shall be checked prior to each use.
This can be done using either a spectroradiometer or a radiometer with sensitivity in the UVA,
calibrated for the same UV exposure source spectrum used for the exposure step of the procedure,
applying the coefficient of calibration to adjust for variance between the UVA radiometer and the
reference spectroradiometer.
5.5 Calibration of the UVA radiometer used to monitor the test sample irradiation
If a UVA radiometer is used, this device shall have been suitably calibrated. This requires that it be
calibrated to the spectroradiometer used to measure the exposure source (as during annual solar
simulator calibration).
Calibration shall be conducted in terms of UVA irradiance (320 nm to 400 nm) and shall be at the
same level at which the test plates are exposed. Once calibrated with the spectroradiometer, the UVA
radiometer may be used to determine the UV doses to be used during the exposure procedure on a day-
to-day basis. Annex B provides the step-by-step calibration procedure.
5.6 Substrate/plate
The substrate/plate is the material to which the test product is to be applied. For this method, PMMA
plates with one rough side of the substrate are to be used and are commercially available. The size of
2
the substrate should be chosen such that the application area is not less than 16 cm .
[9]
The specifications and preparation of this type of plate are described in Annex D.
6 Test method
6.1 Outline of the test procedure
6.1.1 Conduct the calibration and validation of the test equipment, including the UV spectrophotometer
used for transmission/absorbance measurements and the UVA radiometer (or spectroradiometer) used
to measure the UV exposure source, and verify the transmission properties of the test plates as described
in Annex D.
6.1.2 Conduct blank measurements of a glycerin-treated or Vaseline-treated plate for the reference
“blank”, which will be used in the subsequent absorbance measurements.
6.1.3 Conduct in vitro absorbance measurements of the sunscreen product spread on a PMMA plate,
prior to any UV irradiation. Acquire the initial mAf spectrum with A (λ) data.
0
6.1.4 Conduct the mathematical adjustment of the initial UV absorbance spectrum using coefficient
“C” (see the calculation in 6.7.2) to achieve an in vitro SPF (no UV dose) equal to the measured static in
vivo SPF. Initial UVA-PF is calculated using A (λ) and C. A single UV exposure dose, D, is calculated, equal
0 0
2
to 1,2 × UVA-PF in J/cm , for each plate
0
6.1.5 Conduct UV exposure of the same sample as in 6.1.3, according to the calculated UV exposure
dose D.
6.1.6 Measure the in vitro absorbance of the sunscreen product after UV exposure. Acquire the second
UV spectrum with A(λ) data.
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6.1.7 Conduct the mathematical adjustment of the second mAf spectrum (following UV exposure) by
multiplying with the same “C” coefficient, previously determined in 6.1.4. The resulting absorbance curve
is the final adjusted absorbance values.
6.2 Equipment calibration and validation of test plates
Test procedures as described in Annex A are to be completed to validate the wavelength accuracy,
linearity and absorbance limits of the UV spectrophotometer/spectroradiometer to be used for the test
procedure. Validation of the UV properties of the test PMMA plates shall also be conducted as described
in Annex D.
6.3 Absorption measurements through the plate
It is necessary to first determine the absorbance of UV radiation through a “blank” PMMA plate.
Prepare a “blank” plate by spreading a few microlitres of glycerin/vaseline on the roughened side of the
plate. Choose the amount of glycerine/vaseline such that the entire surface is just completely covered
(approximately 15 μl for a 50 mm × 50 mm plate).
Any excess of
...
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