Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) (ISO 24444:2010)

This International Standard specifies a method for the in vivo determination of the sun protection factor (SPF) 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 erythema induced by solar ultraviolet rays.

Kosmetik - Untersuchungsverfahren für Sonnenschutzmittel - In-vivo-Bestimmung des Sonnenschutzfaktors (SSF) (ISO 24444:2010)

Diese Internationale Norm beschreibt ein Verfahren zur In vivo Bestimmung des Lichtschutzfaktors (LSF) von Sonnenschutzmitteln. Diese internationale Norm gilt für Präparate, die in Kontakt mit menschlicher Haut gebracht werden sollen, einschließlich jeglicher Komponenten, die UV Strahlen absorbieren, reflektieren oder streuen können.
Sie dient als eine Basis für die Bewertung von Sonnenschutzmitteln zum Schutz der menschlichen Haut gegen Erytheme oder Sonnenbrand, die (der) durch ultraviolette Sonnenstrahlen induziert wurde(n).

Cosmétiques - Méthodes d'essai de protection solaire - Détermination in vivo du facteur de protection solaire (FPS) (ISO 24444:2010)

L'ISO 24444:2010 spécifie une méthode de détermination in vivo du Facteur de Protection Solaire (FPS) des produits solaires. La présente Norme internationale 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.
L'ISO 24444:2010 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 24444:2010)

Ta mednarodni standard določa metodo za določevanje faktorja zaščite pred soncem (SPF) in vivo pri proizvodih za zaščito pred soncem. Ta mednarodni standard velja za proizvode, ki vsebujejo katero koli komponento, sposobno vpijati, odbijati ali razprševati ultravijolične žarke, namenjene nanosu v stiku s človeško kožo. Zagotavlja podlago za ocenjevanje proizvodov za zaščito človeške kože pred kožno rdečino, ki jo povzročajo sončni ultravijoličnimi žarki.

General Information

Status
Withdrawn
Public Enquiry End Date
19-May-2009
Publication Date
13-Mar-2011
Withdrawal Date
03-Feb-2020
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
03-Feb-2020
Due Date
26-Feb-2020
Completion Date
04-Feb-2020

RELATIONS

Buy Standard

Standard
SIST EN ISO 24444:2011 - natisnjeno za čitalnico
English language
53 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kosmetik - Untersuchungsverfahren für Sonnenschutzmittel - In-vivo-Bestimmung des Sonnenschutzfaktors (SSF) (ISO 24444:2010)Cosmétiques - Méthodes d'essai de protection solaire - Détermination in vivo du facteur de protection solaire (FPS) (ISO 24444:2010)Cosmetics - Sun protection test methods - In vivo determination of the sun protection factor (SPF) (ISO 24444:2010)71.100.70SULSRPRþNLCosmetics. ToiletriesICS:Ta slovenski standard je istoveten z:EN ISO 24444:2010SIST EN ISO 24444:2011en,de01-april-2011SIST EN ISO 24444:2011SLOVENSKI

STANDARD
SIST EN ISO 24444:2011
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN ISO 24444
November 2010 ICS 71.100.70 English Version

Cosmetics - Sun protection test methods -In vivo determination of the sun protection factor (SPF) (ISO 24444:2010)

Cosmétiques - Méthodes d'essai de protection solaire - Détermination in vivo du facteur de protection solaire (FPS) (ISO 24444:2010)

Kosmetik -Untersuchungsverfahren für Sonnenschutzmittel - In-vivo- Bestimmung des LSF (Lichtschutzfaktors) (ISO 24444:2010) This European Standard was approved by CEN on 26 May 2010.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,

B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 24444:2010: ESIST EN ISO 24444:2011

EN ISO 24444:2010 (E) 2 Contents Page Foreword ..............................................................................................................................................................3 SIST EN ISO 24444:2011

EN ISO 24444:2010 (E) 3 Foreword This document (EN ISO 24444:2010) 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 NEN. 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 May 2011, and conflicting national standards shall be withdrawn at the latest by May 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 24444:2010 has been approved by CEN as a EN ISO 24444:2010 without any modification.

SIST EN ISO 24444:2011
SIST EN ISO 24444:2011
Reference numberISO 24444:2010(E)© ISO 2010

INTERNATIONAL STANDARD ISO24444First edition2010-11-15Cosmetics — 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)

SIST EN ISO 24444:2011

ISO 24444:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

COPYRIGHT PROTECTED DOCUMENT

ISO 2010 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel.

+ 41 22 749 01 11 Fax
+ 41 22 749 09 47 E-mail
copyright@iso.org Web
www.iso.org Published in Switzerland
ii © ISO 2010 – All rights reserved
SIST EN ISO 24444:2011

ISO 24444:2010(E) © ISO 2010 – All rights reserved iii Contents Page Foreword............................................................................................................................................................iv Introduction.........................................................................................................................................................v 1 Scope......................................................................................................................................................1 2 Terms and definitions...........................................................................................................................1 3 General principle...................................................................................................................................2 4 Test subjects..........................................................................................................................................3 4.1 Selection of the test subjects...............................................................................................................3 4.2 Number of test subjects........................................................................................................................3 4.3 Test area.................................................................................................................................................4 5 Apparatus and materials......................................................................................................................4 5.1 Source of ultraviolet radiation.............................................................................................................4 5.2 Reference sunscreen formulations.....................................................................................................5 6 Procedure...............................................................................................................................................6 6.1 Main steps..............................................................................................................................................6 6.2 Test conditions......................................................................................................................................6 6.3 Position of the test subjects................................................................................................................6 6.4 Procedure for product application......................................................................................................6 6.5 Procedure for UV exposure..................................................................................................................8 6.6 Product removal....................................................................................................................................9 6.7 Procedure for MED assessment..........................................................................................................9 7 Calculation of the sun protection factor and statistics...................................................................10 7.1 Calculation of the individual SPF (SPFi)...........................................................................................10 7.2 Calculation of product SPF................................................................................................................10 7.3 Statistical criterion..............................................................................................................................10 7.4 Validation of the test...........................................................................................................................10 8 Test report............................................................................................................................................11 Annex A (normative)

Selection criteria for the test subjects.......................................................................12 Annex B (normative)

Definition of the UV solar simulator output...............................................................15 Annex C (normative)

SPF reference sunscreen formulations.....................................................................23 Annex D (normative)

Calculations and statistics..........................................................................................32 Annex E (informative)

Colorimetric determination of skin colour typing and prediction of the minimal erythemal dose (MED) without UV exposure.....................................................................38 Bibliography......................................................................................................................................................45

SIST EN ISO 24444:2011

ISO 24444:2010(E) iv © ISO 2010 – All rights reserved 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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. ISO 24444 was prepared by Technical Committee ISO/TC 217, Cosmetics. SIST EN ISO 24444:2011

ISO 24444:2010(E) © ISO 2010 – All rights reserved v 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 volunteers. It uses ultraviolet radiation usually from an artificial source. Different standard methods are available and described in the technical report ISO/TR 26369[4]. These standards are similar by some parameters but different by others. Differences can lead to discrepancy of results. Harmonization is therefore necessary to get the same SPF value for a single product whatever the country in which it is tested. SIST EN ISO 24444:2011

SIST EN ISO 24444:2011

INTERNATIONAL STANDARD ISO 24444:2010(E) © ISO 2010 – All rights reserved 1 Cosmetics — Sun protection test methods — In vivo determination of the sun protection factor (SPF) 1 Scope This International Standard specifies a method for the in vivo determination of the sun protection factor (SPF) 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 erythema induced by solar ultraviolet rays. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 ultraviolet radiation UVR electromagnetic radiation in the range of 290 nm to 400 nm 2.1.1 ultraviolet B UVB electromagnetic radiation in the range of 290 nm to 320 nm 2.1.2 ultraviolet A UVA electromagnetic radiation in the range of 320 nm to 400 nm NOTE UVA II = 320 nm to 340 nm; UVA I = 340 nm to 400 nm. 2.2 erythema reddening of the skin caused by UV radiation 2.3 sunscreen products products containing any component able to absorb, reflect or scatter UV rays, which are intended to be placed in contact with human skin 2.4 minimal erythemal dose MED lowest dose of ultraviolet radiation (UVR) that produces the first perceptible unambiguous erythema with defined borders appearing over most of the field of UV exposure, 16 h to 24 h after UV exposure SIST EN ISO 24444:2011

ISO 24444:2010(E) 2 © ISO 2010 – All rights reserved 2.4.1 MEDu MED on unprotected skin 2.4.2 MEDp MED on product protected skin 2.5 individual sun protection factor SPFi ratio of the minimal erythemal dose on product protected skin (MEDp) to the minimal erythemal dose on unprotected skin (MEDu) of the same subject: MED(protectedskin)MEDpSPFi==MED(unprotectedskin)MEDu NOTE SPFi is expressed to one decimal place (see 7.1). 2.6 sun protection factor of a product SPF arithmetic mean of all valid individual SPFi values obtained from all subjects in the test NOTE SPF is expressed to one decimal place (see 7.2). 2.7 test area back between the scapula line and the waist 2.8 test site site where a product is applied or the site used for the determination of the unprotected MED 2.9 exposure sub-sites skin exposed spots 2.10 individual typology angle ITA° value characterizing the skin colour of the subject 3 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 is 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 and 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 redness 16 h to 24 h after UV radiation, by the judgment of a competent evaluator. SIST EN ISO 24444:2011

ISO 24444:2010(E) © ISO 2010 – All rights reserved 3 The minimal erythemal dose (MED) for unprotected skin (MEDu) and the MED obtained after application of a sunscreen product (i.e. the MED for product protected skin, MEDp) shall be determined on the same subject on the same day. An individual sun protection factor (SPFi) for each subject tested is calculated as the ratio of individual MED on product protected skin divided by the individual MED on unprotected skin i.e. MEDp/MEDu. The sun protection factor for the product (SPF) is the arithmetic mean of all valid SPFi results from each subject in the test. 4 Test subjects 4.1 Selection of the test subjects 4.1.1 General For subject inclusion and non inclusion criteria, refer to Annex A. 4.1.2 Skin phototype of the test subjects Test subjects included in the SPF test shall be only phototypes I, II or III according to Fitzpatrick[7] or shall have an ITA° value > 28° by colorimetric methods (see Annexes A and E) and be untanned on the test area. An SPF test should not contain subjects who are all of the same phototype. A 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). 4.1.3 Age restriction Test subjects below the age of consent or older than 70 y shall not be included in the SPF test panel. 4.1.4 Frequency of participation in tests Since a sufficient interval after a previous test is needed in order to allow for reversal of skin tanning resulting from that previous test, a test site that has been exposed to UV should not be used in a subsequent test before two months have elapsed and the site is clear. 4.1.5 Ethics and consent All testing shall be done in accordance with the Declaration of Helsinki[8] and National Regulations regarding human studies, if any. Informed, written (signature) consent shall be obtained from all test subjects. 4.2 Number of test subjects The minimum number of valid SPFi results shall be 10 and the maximum number of valid SPFi 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 SPF. 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 SPF according to 6.7.4 or because of non-compliance with the related protocol. SIST EN ISO 24444:2011

ISO 24444:2010(E) 4 © ISO 2010 – All rights reserved In order to determine the number of test subjects, the 95 % confidence interval (95 % CI) on the mean SPF 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 SPF is within ±17 % of the mean SPF. If it is not within ±17 % of the mean SPF, 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. 4.3 Test area The back is the chosen anatomical region for the test area. The individual product test sites and the unprotected test site shall be delineated within the region between the scapula line and the waist. Skeletal protrusions and extreme areas of curvature should be avoided. 5 Apparatus and materials 5.1 Source of ultraviolet radiation 5.1.1 General The artificial light source used shall comply with the source spectral specifications as described in 5.1.2 and Annex B. A xenon arc solar simulator with appropriate filters is recommended. 5.1.2 Quality of ultraviolet radiation 5.1.2.1 The solar UV simulator shall emit a continuous spectrum with no gaps or extreme peaks of emission in the UV region. The output from the solar UV simulator shall be stable, uniform across the whole output beam (particularly important for a single large-beam) and suitably filtered to create a spectral quality that complies with the required acceptance limits (see Table B.1). 5.1.2.2 To ensure that appropriate amounts of UVA radiation are included in the spectrum of the solar UV simulator, the total radiometric proportion of the UVA II (320 nm to 340 nm) irradiance of the simulator shall W 20 % of the total UV (290 nm to 400 nm) irradiance. Additionally, the UVA I region (340 nm to 400 nm) irradiance shall be W 60 % of the total UV irradiance. 5.1.2.3 The source spectral specification is described in terms of cumulative erythemal effectiveness by successive wavelength bands from < 290 nm up to 400 nm. The erythemal effectiveness of each wavelength band is expressed as a percentage of the total erythemal effectiveness from < 290 nm to 400 nm, or as the percentage relative cumulative erythemal effectiveness (% RCEE). The definition and calculation of % RCEE values is described in Annex B and the acceptance limits are given in Table B.1. 5.1.3 Total irradiance (UV, visible and near infrared rays) If total irradiance is strong, an excessive feeling of heat or pain may be induced in the irradiated skin of subjects. Therefore, total irradiance shall not exceed 1 600 W/m2. When total irradiance is < 1 600 W/m2, it shall still be confirmed, prior to conducting an SPF test, that the irradiance to be used (UV, visible and near-infrared rays) will not induce an excessive feeling of heat in the skin. 5.1.4 Uniformity of beam 5.1.4.1 When a large-beam UV source is used to simultaneously expose several sub-sites (i.e. at least two sub-sites) within an irradiation series by varying the exposure time, the intensity of the beam shall be as uniform as possible. The minimum beam irradiance, at any sub-site, shall be no more than 10 % lower than SIST EN ISO 24444:2011

ISO 24444:2010(E) © ISO 2010 – All rights reserved 5 the maximum beam irradiance at any sub-site. If the variation exceeds 10 %, then appropriate compensation for different irradiance should be made in the exposure time on each sub-site. 5.1.4.2 For a small beam UV source, which exposes sub-sites individually, the erythema generated following exposure shall be as uniform as possible. An uneven erythema in unprotected skin (such as a half-moon shape) indicates that the irradiance is not uniform and the delivery system shall be corrected. 5.1.5 Maintenance and monitoring the UV solar simulator output 5.1.5.1 Radiometry Before UV exposure of each test site, the UV irradiance should be measured and recorded with a radiometer calibrated against a spectroradiometric measurement of the solar simulator output.

5.1.5.2 Spectroradiometry It is recommended that a complete spectroradiometric check (UVA and UVB) of output spectrum and intensity be made by the laboratory at least once every 18 months or after 3 000 h of lamp running time and after changing any significant physical (optical) component of the solar simulator. This periodical inspection should be conducted by a competent and suitably qualified person. The simple use of specific filters is not in itself adequate assurance that the UV output is of the correct quality. Detailed instructions for ensuring correct lamp output are given in Annex B. 5.2 Reference sunscreen formulations 5.2.1 General The method is controlled by the use of one of three reference sunscreen formulations to verify the test procedure. Therefore one of the prescribed reference formulations shall be measured on the same day as products are tested. Whether a low or high SPF reference formulation is to be used depends on the expected SPF of the test products. 5.2.2 Expected SPF < SPF 20 Any one of the following reference sunscreen formulations shall be used: P2, P3 or P7. If a high SPF reference formulation is used, there is no necessity to also include the low SPF reference formulation in the test even though there may be low SPF test products. 5.2.3 Expected SPF W SPF 20 One of the following reference sunscreen formulations shall be used: P2 or P3. If a high SPF reference formulation is used, there is no necessity to also include the low SPF reference formulation in the test even though there may be low SPF test products. 5.2.4 Acceptance SPF limits for the reference sunscreen formulations Acceptance SPF ranges for the reference sunscreens are shown in Annex C. If the mean SPF obtained in any test does not fall within the acceptance limits of the reference values then the entire test (i.e. all test products) shall be rejected. If the 95 % confidence interval on the mean SPF for the reference sunscreen falls outside a range defined by the mean reference sunscreen SPF ±17 %, then the entire test (i.e. all test products) shall be rejected. SIST EN ISO 24444:2011

ISO 24444:2010(E) 6 © ISO 2010 – All rights reserved 5.2.5 Formulae and preparation of the reference sunscreen formulations The formulae details and manufacturing instructions for the reference formulations are given in Annex C. 6 Procedure 6.1 Main steps ⎯ delineation of test sites on the back of the subject; ⎯ weighing of the product; ⎯ application of the product; ⎯ waiting period before UV exposure; ⎯ UV exposure; ⎯ MED assessment; ⎯ calculations. 6.2 Test conditions Product application, UV exposures and MED assessment should be carried out in stable conditions, with the room temperature maintained between (22 ± 4) °C. 6.3 Position of the test subjects All steps in the procedure shall be performed in the same position: an upright, seated or prone position. Powder should be tested in the prone position to prevent the samples from falling off the surface. 6.4 Procedure for product application 6.4.1 General The amount of product applied and the uniformity of spreading on the test sites affect the magnitude and variability of the test results. It is therefore very important to follow the recommendations set out in 6.4.2 to 6.4.5. 6.4.2 Test sites and product application 6.4.2.1 The test sites intended for UV exposure shall be free from blemishes and have an even colour tone. 6.4.2.2 The minimum total area for a test site for product application shall be 30 cm2 and the maximum shall be 60 cm2. 6.4.2.3 The positions of the test products and reference sunscreen test sites shall be distributed randomly on the backs of subjects over the whole test group in order to reduce error arising from anatomical differences in skin. The unprotected test site used to determine MEDu should be randomized as one of the test sites across the test area and across subjects. 6.4.2.4 There shall be a minimum distance of 1 cm between the borders of adjacent test sites. SIST EN ISO 24444:2011

ISO 24444:2010(E) © ISO 2010 – All rights reserved 7 6.4.2.5 Before product application, the test area may be cleaned by using a dry cotton pad or equivalent. 6.4.2.6 The test sites shall be delineated by a method which does not interfere with the test or harm the subject e.g. skin marker and/or a template made from non-absorbent material. 6.4.3 Amount of product applied 6.4.3.1 The amount of test product and reference sunscreen formulation applied to the skin before spreading shall be (2,00 ± 0,05) mg/cm2. 6.4.3.2 The balance used to weigh the products should be capable of weighing to the nearest 0,000 1 g, i.e. to the nearest 0,1 mg. 6.4.3.3 All products should be homogeneous and should be shaken if necessary, before weighing, to ensure uniform dispersion. 6.4.3.4 When handling the product during weighing or before application to the skin, take appropriate measures to prevent evaporative loss of the volatile components. It is important that the total quantity of weighed product is transferred to the product application site. 6.4.3.5 The amount of product to be applied is weighed in a syringe or in another device such as a watch glass. A method of weighing by loss is strongly recommended. 6.4.4 Mode of delivery 6.4.4.1 General The use of a finger cot is optional but is recommended. When employed, a new finger cot shall be used for each new application of product and should not be pre-saturated with the test product. When a naked finger is used, the finger should be cleaned between product applications. 6.4.4.2 Liquid type products (e.g. lotions, liquids, milks, creams, sprays and sticks) 6.4.4.2.1 To aid uniform coverage, droplets (approximately 15 per 30 cm2, 30 per 60 cm2) of the product should be deposited within the test site using a syringe/pipette, then spread over the whole test site using light pressure. 6.4.4.2.2 Spreading time should be in the range of (35 ± 15) s depending on the surface and ease of spreading of the product. 6.4.4.3 Powders 6.4.4.3.1 In the case of powder products, aliquots of powder should be transferred to the skin in a grid-like manner, using a spatula or finger. 6.4.4.3.2 The accumulated powder is tapped and then spread over the whole test site using a fin

...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.