ISO/TR 26369:2009

Cosmetics — Sun protection test methods — Review and evaluation of methods to assess the photoprotection of sun protection products

ISO/TR 26369:2009 reviews and evaluates the methods which are currently used to assess, for regulatory or self-regulatory purposes, the photoprotection of sun protection products applied on human body. It is applicable to SPF and UVA protection, and both in vivo and in vitro methods.

Cosmétiques — Méthodes d'essai de protection solaire — Revue systématique et évaluation des méthodes usuelles de mesure de la protection solaire fournie par les produits de protection solaire

General Information

• Status: Published
• Publication Date: 20-Aug-2009
• ICS: 71.100.70 - Cosmetics. Toiletries
• Technical Committee: ISO/TC 217 - Cosmetics
• Drafting Committee: ISO/TC 217 - Cosmetics
• Current Stage: 6060 - International Standard published
• Completion Date: 21-Aug-2009

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 26369
First edition
2009-09-01

Cosmetics — Sun protection test
methods — Review and evaluation of
methods to assess the photoprotection of
sun protection products
Cosmétiques — Méthodes d'essai de protection solaire — Revue
systématique et évaluation des méthodes usuelles de mesure de la
protection solaire fournie par les produits de protection solaire





Reference number
ISO/TR 26369:2009(E)
©
ISO 2009

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ISO/TR 26369:2009(E)
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ii © ISO 2009 – All rights reserved

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ISO/TR 26369:2009(E)
Contents Page
Foreword .iv
1 Scope.1
2 Terms and definitions .1
3 Principle.1
4 Sun protection test methods.2
4.1 SPF in vivo .2
4.2 SPF in vitro.2
4.3 UVA in vivo.2
Bibliography.38

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ISO/TR 26369:2009(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.
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.
In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
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/TR 26369 was prepared by Technical Committee ISO/TC 217, Cosmetics.

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TECHNICAL REPORT ISO/TR 26369:2009(E)

Cosmetics — Sun protection test methods — Review and
evaluation of methods to assess the photoprotection of sun
protection products
1 Scope
This Technical Report reviews and evaluates the methods which are currently used to assess, for regulatory
or self-regulatory purposes, the photoprotection of sun protection products applied on the human body.
It is applicable to SPF and UVA protection, and both in vivo and in vitro methods.
This Technical Report does not include the aspects of labelling in a wide sense.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
ultraviolet
UV
electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft X-rays and
so named because the spectrum consists of electromagnetic waves with frequencies higher than those that
humans identify as the color violet (purple)
NOTE In this Technical Report the following wavelengths are considered: UVA: 320 nm to 400 nm; UVB: 290 nm to
320 nm.
2.2
sun protection factor
SPF
〈of a sunscreen〉 laboratory measurement to assess the effectiveness of sunscreens against UV erythema
NOTE 1 The higher the SPF, the more protection a sunscreen offers.
NOTE 2 The SPF is a ratio between the ultraviolet dose required to produce minimal erythema reaction (redness) in
protected skin (skin with sunscreen) compared to unprotected skin (skin without any sunscreen).
3 Principle
This systematic review and evaluation of the methods are conducted for development of those ISO Standards
which assess the photoprotection provided by sun protection products applied on the human body. It will serve
as a technical/scientific framework to identify the most suitable methods for standardization.
The key parameters and elements are listed in Tables 1 to 6 in order to enable an easy comparison of the
methods.
© ISO 2009 – All rights reserved 1

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ISO/TR 26369:2009(E)
4 Sun protection test methods
4.1 SPF in vivo
The SPF in vivo methods currently used are given in Table 1.
4.2 SPF in vitro
The SPF in vitro methods based on transmittance evolved from the Diffey proposal and new methods based
on measurement of free radicals or use of skin biopsies are given in Tables 2 and 3. The relevant parameters
of methods based on transmittance are given in Table 4.
4.3 UVA in vivo
The methods reviewed by ISO/TC 217 are given in Tables 5 and 6.

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ISO/TR 26369:2009(E)
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Table 1 — SPF in vivo methods currently used
a
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
UV definition (UVB, UVA) UVB: 290 nm to 320 nm UVB: 290 nm to 320 nm Solar UVR: 290 nm to 400 nm
UVA: 320 nm to 400 nm UVA: 320 nm to 400 nm UVB: 290 nm to 320 nm
UVAII 320 nm to 340 nm UVAI 340 nm to UVA: 320 nm to 400 nm
400 nm
Volunteers selection
Ethical considerations Helsinki, national regulations, medical status Not defined Medical questionnaire
Age limitation Yes, excluded below age of consent Not defined Not defined
Informed consent Yes, with signatures Yes Yes
Exclusion criteria Pregnant, lactating women Skin disease, abnormal responses to UV, Abnormal response to medication, UV radiation,
phototoxic or photo-allergic response, allergies to topically applied cosmetics
Photosensitizing medication
medication (topical or systemic) known to
Phototoxic or photosensitizing medication
produce abnormal sunlight responses
Dermatological problems, history of
abnormal response to sun
Sunburn, scars, active dermal lesions and
uneven skin tones on the areas to be tested
Tanning beds
No sun damage, marks, blemishes or nevi
Test subjects
Skin phototype and skin Fitzpatrick skin type (s) I, II, III or skin colour Phototypes I, II, III Phototypes I, II, III
colour (ITA° value > 28° very fair, fair-skin and
Fair skin colour Fair skin colour
intermediate skin colour) and untanned on
the test area
Test area Back, between scapula line and waist The back between the beltline and the shoulder Back, clean dry skin, without any suntan or
blade (scapulae) and lateral to the midline sunburn, active dermal lesions, excessive hair,
Skeletal protrusions and extreme areas of
uneven skin tones
curvature should be avoided
Time, interval between No less than 2 months, sufficient interval for Not defined Not defined
two tests reversal of skin tanning until the site is clear
a
The numbers in brackets refer to the Bibliographic references.

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
Source of UV radiation
Solar simulator Continuous emission spectrum with no gaps Continuous emission spectrum 290 nm to Xenon arc is preferred
or extreme peaks 400 nm, similar to sunlight at sea level, 10°
Filtration No peak in UVB; continuation in the UVA
zenith angle
Stable output
WG320 filter, dichroic mirror or heat absorbing
< 1 % energy < 290 nm
Xenon Arc lamp recommended with dichroic filter
mirror and WG320 + UG11/1 mm u 5 % energy > 400 nm
Stable output after appropriate warm-up time
Acceptance limits % RCEE defined in different bands Not defined < 0,01 % < 290 nm
W.L. range: RCEE%: “Red” & “blue” acceptance limits (± 4 nm): graph
%RCEE UVA2/UVA1 u 290 nm < 0,1 %
290 nm to 300 nm 1,0 % to 8,0 %
290 nm to 310 nm 49,0 % to 65,0 %
290 nm to 320 nm 85,0 % to 90,0 %
290 nm to 330 nm 91,5 % to 95,5 %
290 nm to 340 nm 94 % to 97 %
290 nm to 400 nm 99,9 % to 100 %
UVAII W 20 % UVAI W 60 % of the total UV
irradiance to ensure that appropriate
amounts of UVA radiation are included
Irradiance uniformity As uniform as possible, no more than 10 % Within 10 % Uniformity of spot appearance
for large beam (no half-moon shape)
2
Total irradiance Lower than 160 mW/cm Not defined Not defined

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
(Spectro) radiometry
Checking of UV source Spectroradiometric check at least once a Measured periodically with an accurately- Not defined
emission spectrum by year by an independent expert or each time calibrated spectroradiometer system or
spectroradiometry a significant physical (optical) component is equivalent instrument
changed
Colipa guidelines “monitoring of UV light
sources”
adiometry Before exposure of each test te, che ng t defined Before a d after eac test series, v ations
R si cki No n h ari
with a calibrated radiometer kept to a minimum; UV monitor response
restricte to U ange rec mm nded
d V r o e
Test site description
Mode of delineation Skin marker and/or template made from a Outlined with ink Means which do not interfere with the test or
non-absorbent materia harm the subjec
l t
2 2 2 2
Application surface Between 30 cm and 60 cm Minimum 50 cm , e.g. 5 × 10 cm Minimum of 30 cm , maximum not defined
Space between test sites Minimum distance of 1 cm Not defined Not defined
Test site pre-treatment Possible with dry cotton pad Not defined Warm water and toweling

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
Product quantity
and application
2 2 2
Quantity applied 2 mg/cm ± 2,5 % 2 mg/cm 2 ± 0,1 mg/cm
Sensitivity of the balance, at least 0,1 mg
Method of weighing by loss
Position of volunteers Position in a way to ensure that the No indication, same position as delineation? Not defined
complete amount of test product is evenly
applied and remains on skin, seated or
prone position, excepted for powder
products tested only in prone position
Mode of delivery Lotion, liquid, milk, cream, spray: Volumetric syringe Weighing boat or weighed syringe
syringe/pipette droplets on the whole test
Pastes and ointments shall be weighed Spreading according to the sponsor instructions
site
Product film lightly and evenly applied with
Spreading time in the range of 20 s to 50 s,
uniform thickness
low pressure of application
Validation of the method by the test facility
Powders: spatula, finger, Applicator puff. +
water
CD-ROM for application procedure training
for emulsions and powders
Room temperature, air Room temperature between 18 °C and Not defined Air-conditioned, 20 °C and 25 °C
conditioning 26 °C
Drying time 15 min to 30 min At least 15 min At least 15 min
Finger cot If appropriate Yes Yes recommended, other appropriate means
may be used
Randomization Yes Yes Not defined
Blinded application Not defined Yes Not defined

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
UV exposures
Position of volunteers Position shall be the same for product Upright or prone position Seated or prone position
applications, for UV exposure and for MED
assessment
2 2 2 2
Exposure sub-site surface At least 0,5 cm , recommended 1 cm W 1 cm Approximately 1 cm
Distance between sub-sites at least 0.8 cm Distance between sub-sites at least 1 cm and
1 cm from any edge of the test site
Number of sub-sites Minimum of 5 for MEDu and MEDp 5 for the unprotected area Minimum of 5 for MEDu and MEDp
7 for the protected areas
Provisional individual The day prior to the product testing, Usually the day prior to testing a product Prediction by experienced tester or provisional
MEDu determined again on the same day as the MEDu the day before
Determined again on the same day as the test
test sunscreens or estimation of the MEDu
sunscreens
by colorimetry (ITA°)
n n
Progression of UV dose Geometric progression of either (1,25 ) or Geometric progression (1,25 ) for the Unprotected MED re-determined with a dose
n
(1,12 ) for the unprotected area. For the unprotected area range of ca 0,6 to 1,5 provisional MEDu
protected areas, a minimum of five sub-sites
For the protected areas geometric series of five For protected skin the dose range is multiplied
centered on the expected SPF × MEDu shall
exposure where the middle exposure is placed by the expected SPF
be exposed with a geometric progression of
to yield the expected SPF plus two other
n n
either (1,25 ) or (1,12 )
Increments between sub-sites no more than
exposures placed around the middle exposure
1,25
A maximum progression of 1,12 must be
According to the expected SPF (X)
used for expected SPF > 25
u 1.118 for SPF W 25
SPF < 8: 0,64, 0,8, 0,9, 1,1 .1, 1.25, 1,56X
SPF 8 to 15: 0,69, .83, 0,91, 1, 1,09, 1,2, 1.44X
SPF > 15: 0,76, 0,87, 0,93,1, 1,07,1,15, 1,32X
Randomized UV exposure Not defined Yes if only one product is being tested Not defined
Product removal Products may be removed gently using a Not defined Not defined
cotton pad and mild lotion
Ambient conditions 18 °C to 26 °C Not defined Not defined

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ISO/TR 26369:2009(E)
8 © ISO 2009 – All rights reserved
Table 1 (continued)
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
Response description
Definition of response The MED is the lowest UV dose that The MED is the quantity of erythema-effective Minimum quantity of radiant energy to produce
produces the first perceptible unambiguous energy required to produce the first perceptible a perceptible reddening of human skin. The first
erythema with defined borders appearing unambiguous redness reaction with clearly subsite to show a minimal redness perceptible
over most of the field, 16 h to 24 h after UV defined borders at 22 h to 24 h post-exposure to the eye, (with normal vision)
exposure
2 2 2
Units J/m or mJ/cm or MED units or time J/m Energy or time (if flux constant)
(seconds) if the flux is constant throughout
the test
Time of assessment 16 h to 24 h post-exposure 22 h to 24 h post-exposure 16 h to 24 h post-exposure
MEDu and MEDp on same day
Conditions of observation Sufficient and uniform illumination: at least Illumination: tungsten or warm white fluorescent Full daylight, or a tungsten filament light
450 lx light bulb providing adequate illumination; matt neutral
wall colours
450 lx to 550 lx (at the test site)
Position of volunteers Same position used for the UV exposure Same position used for the UV exposure Seated or prone position
Biological endpoint Erythema Erythema Erythema
Evaluator Normal colour and acuity vision different Different from the person who applied the Normal vision, colour vision checked
from the person who applied the sunscreen sunscreen or administered the UV doses
or administered the UV doses
Data rejection criteria on All sites visible or no site visible, responses All sites visible or no site visible, responses on If the result obtained using the reference
individual test site on the treated sites randomly absent the treated sites randomly absent (indication of product on a subject varies by > 25 % of the
uneven spreading) average value of that test series the results of
Rejection of the subject if MEDu or MEDp of
the subject are excluded
standard product not determined
If more than two subjects return SPFs for the
test product which vary by > 25 % of the mean
SPF, a new sample should obtained

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters International 2006 [1] FDA 1999 [2] Australia 1998 [3]
Reference sunscreen
formulations
Reference sunscreen Expected SPF < SPF 20 P2 or P3 or P7 Homosalate 8 % SPF 4,47 (S.D.: 1,279) On each test subject either:
formulations used
Expected SPF W SPF 20 P2 or P3 *Homosalate 8 % SPF 4,47
The same has to be tested on every subject *P3 SPF 15,5
in the same series of at least ten subjects
or values derived from the laboratory’s historical
record on its test results
Acceptance limits (ranges) Mean SPF ± 2 SE The SPF must fall within the range 4,47 ± 1,279 * Homosalate 8 % SPF ± 2 SD ∈ [4 to 5]
and the 95 % CI of the mean SPF must contain
P2: 16,6 (14,2 to 19,0) * P3 SPF ± 2 SD ∈ [12.5 to 18.5]
the value four
P3: 16,2 (13,8 to 18,7) P7: 5,1 (4,4 to 5,9)
Calculation and results
Number of test subjects Minimum of ten, maximum of twenty five No more than twenty five, at least twenty valid Minimum of ten, maximum not defined
data
Calculation of mean SPF Arithmetic mean, minimum of ten valid Mean, SD, t value at 5 % with n − 1, SEM Arithmetical mean, expressed to one decimal
results and a maximum of twenty shall be point
used for the calculation of SPF
A maximum of five results may be excluded
from the calculation of the mean SPF; each
exclusion has to be justified
Statistical criterion 95 % confidence interval should fall within No SEM u 7 % of mean SPF for valid result
the range of ± 17 % of the mean SPF
A minimum of ten valid results is only
sufficient if the criterion is fulfilled, otherwise
the number of subjects is increased
stepwise from ten until the statistical criterion
is met up to a maximum of twenty valid
results

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ISO/TR 26369:2009(E)
10 © ISO 2009 – All rights reserved
Table 1 (continued)
Parameters Canada 2002 [4] Korea 2004 [5] China 2002 [6]
UV definition (UVB, UVA) Not defined UVB: 290 nm to 320 nm UVB: 290 nm to 320 nm
UVA: 320 nm to 400 nm UVA: 320 nm to 400 nm
Selection of volunteers
Ethical considerations Medical history Medical status checked Not defined
Age limitation Not defined 18 y to 60 y 18 y to 60 y
Informed consent Not defined Not defined Not defined
Exclusion criteria Standard criteria Standard criteria Standard criteria
Test subjects
Skin phototype Burns readily, tans slowly I, II, III Individuals with skin type I, II, III sensitive to the
sunlight or UV exposure, burns easily and tans
Example of questionnaire is given
minimally
Skin colour Light Not defined Not defined
(uniform colour without pigmentation)
Test area The back between the waist and the The back without any skin damage or extreme Back or other body site
shoulder blades and to either side of the hair
mid-line
Time, interval between Not defined Not defined Not defined
two tests
Source of UV radiation
Solar simulator Sun or solar simulator Light source similar to the sunlight Only xenon arc
Filtration Solar simulator is preferred and xenon arc is Xenon arc with a continuous emission spectrum Continuous emission of UV from 290 nm to
recommended with a WG-320/1 mm filter with no gap or extreme peaks, or similar devices 400 nm
+ dichroic mirror + IR filter Stable intensity < 290 nm < 1 %
> 400 nm < 5 %
Constant output
Acceptance limits Not defined Not defined Not defined
%RCEE UVA2/UVA1 λ < 290 nm should be removed
Irradiance uniformity Not defined Not defined Within 10 %
Total irradiance Not defined Not defined Not defined

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters Canada 2002 [4] Korea 2004 [5] China 2002 [6]
Spectroradiometry
Checking of UV source Calibration and period c check ng Not defined Not def ned
i i i
emission spectrum by
spectroradiometry
Radiometry Robertson Berger meter Not defined Not defined
Calibration is needed, able to measure the
output to within 1 % of the absolute value
Test site description
Mode of delineation Suitable and lasting marker Not defined, however two examples of Not defined
irradiation area demarcation are given
2 2 2
Application surface Approximately 50 cm Minimum 24 cm or larger Minimum 30 cm
Space between test sites Not defined Not defined Not defined
est site pre-treatmen ot defined ean and dry ot def ned
T t N Cl N i
Position of volunteers Prone or upright, the same as for the Not defined Not defined
exposure
Product quantit
y
and application
2 2 2 2 2
Quantity applied 2 mg/cm or 2 µl/cm 2,0 mg/cm or 2,0 µl/cm 2 mg/cm
Position of volunteers ication o indication o indication
No ind N N
Mode of delivery No indication No indication Weighing, application as uniformly as possible
Room temperature, air No indication No indication No indication
cond oning
iti
Drying time At least 15 min 15 min 15 min
Finger cot No indication Rubber thimble Emulsion glove
Randomization Not specified Not defined Not defined
Blinded a ion ot sp ied ot defined ot def ned
pplicat N ecif N N i

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters Canada 2002 [4] Korea 2004 [5] China 2002 [6]
UV exposures
Position of volunteers Prone or upright position Comfortable position Bent forward position or recumbent prostrate
position
2 2
Exposure sub-site surface At least 1 cm 0,5 cm or larger, 1 cm between each sub-site, Not defined
0,5 cm from the borders of the site
Number of sub-sites Five for the unprotected area and for the Six for the unprotected and protected areas Five for the unprotected area
protected areas
Five to seven for the protected areas
Provisional individual Predetermination of the unprotected MED Expected MED is determined based on the skin Predetermination of the unprotected MED 24 h
MEDu the day before the testing phase type the day before prior to the testing phase
MEDu on the same day as Determined again on the same day as the No Determined again on the same day as the MED
the tested products MED with test sunscreens with test sunscreens
n n
Progression of UV dose Geometric progression (1,25 ) 25 % or lower when the expected SPF < 20 Geometric progression (1,25 ) for the
unprotected area
15 % when the SPF is W 20 and < 30
W he expecte SPF 1 e dose increase
hen t d < 5 th
10 % or low r when the SPF i 30
e s W
rate is 25 %:
0,64, 0,8, 0,9, 1,00,1 .1, 1,25, 1,56X
When the expected SPF >15, the dose increase
rate is 15 %: 0,76, 0,87, 0,93, 1,00, 1,07, 1,15,
1,32X
Tw he 1,00X
o doses are added around t dose X
(expected SPF × MEDu)
Randomized UV exposure Not defined Not defined Not defined
Product removal ot defined ot defined ot def ned
N N N i
Ambient conditions Not defined Not defined Not defined

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ISO/TR 26369:2009(E)
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Table 1 (continued)
Parameters Canada 2002 [4] Korea 2004 [5] China 2002 [6]
Response description
Definition of response The amount of solar radiation or solar The minimum erythema dose is defined as the The smallest UV dose (Joules per square
simulated radiation needed to produce a lowest dose that produces the first perceptible metre) or the shortest time (seconds) required
barely noticeable erythema (redness) on unambiguous erythema with defined borders to produce defined skin erythema in the test site
human skin appearing over most of the field of UV and its boundaries
exposure, 16 h to 24 h after UV exposure
Units Using constant irradiation conditions MED is Not defined Joules per square metre or seconds
proportional to the duration of exposure
(seconds)
Time of assessment 16 h to 24 h post exposure 16 h to 24 h post exposure 24 h post exposure
Conditions of observation Consistent conditions of illumination, Sufficient light source Not defined
(light) background colour
Position of volunteers Not defined Not defined Not defined
Biological endpoint Erythema Erythema Erythema
Evaluator Human eye or reflectometer, at least one By two or more trained evaluators No indication
evaluator
MEDu and MEDp shall be determined by the
same person in same conditions
Data rejection criteria All sub-sites visible or no sub-site visible, Not defined All sites visible or no site visible, responses
responses randomly absent randomly absent

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ISO/TR 26369:2009(E)
14 © ISO 2009 – All rights reserved
Table 1 (continued)
Parameters Canada 2002 [4] Korea 2004 [5] China 2002 [6]
Reference sunscreen
formulations
Reference sunscreen Homosalate 8 % Homosalate 8 % for SPF < 20 Homosalate 8 % SPF 4,47 (S.D.: 1,279)
formulations used
or for high SPF values a standard with a High SPF standard for SPF W 20
comparably high SPF should be used
Acceptance limits (ranges) 4,11 ± 0 103 Homosalate 8 % The SPF mus fall w thin the range 4,47 ± 1,279
, t i
and the 95 % CI of the mean SPF must contain
The SPF must fall within the range 4,47 ± 1,279
the v lue four
a
gh SPF standard
Hi
The SPF must fall within the range 15,5 ± 3,0
Calculation and results
umber of test subje ts Minimum of twenty males and females 10; maximum number not efined 10 (minim m 11)
N c , W d > u
Calculation of mean SPF Arithmetic mean, SE Arithmetic mean Arithmetic Mean, SD, SE
95 % confidence interval SPF is the integer part
Statistical criterion SE ld be 5 % of the mean 95 % C should be w thin the ange of 20 % of SE must range within 10 % of the arithmetic
shou u I i r ±
the mean; if the statistical criteria is not met, the mean, otherwise more subjects should be
number of subjects is increased gradual or added until the final result matches the criteria
ly
reset the testing conditions and then test
repeatedly to reach the criterion

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ISO/TR 26369:2009(E)
© ISO 2009 – All rights reserved 15
Table 2 — Methods based on spectral transmittance (Diffey)
Method I [18] II III [19] IV [20] VI [22]
Parameters
Spectra analyser
Spectra analyser system Optronics 742, single Optometrics SPF-290S, Sunscreen tester equipped Four different spectra Labsphere UV1000S, dual
monochromator w th single monochromator with a sensor having a analysers (OL754, diode array, integrating
i ,
bandwidth of 1,5 nm collection of transmitted spectral sensitivity adjusted Uvikon 933, Labsphere sphere d/0° geometry
and most of the diffracted to s( for determining UV1000S and sunscreen
λ)
e
...