Photodermatol Photoimmunol Photomed 2005; 21: 84–92
Blackwell Munksgaard
Copyright r Blackwell Munksgaard 2005
Ultraviolet protective performance of photoprotective lipsticks: change of
spectral transmittance because of ultraviolet exposure
H. Maier1, G. Schauberger2, B. S. Martincigh3, K. Brunnhofer4, H. Hönigsmann1
1
Division of Special and Environmental Dermatology, Medical University of Vienna, Vienna, Austria, 2Institute of Medical Physics and Biostatistics,
University of Veterinary Medicine Vienna, Vienna, Austria, 3School of Pure and Applied Chemistry, University of KwaZulu-Natal, Howard College
Campus, Durban, Republic of South Africa, and 4Austrian Consumers’ Association, Vienna, Austria
Background: Photoinstability of sunscreens because
of ultraviolet (UV) exposure is a well-known and common phenomenon. Recently, it was also shown that
sunscreens with complex filter combinations are photoinactivated by UV exposures, which can easily be acquired by solar exposure over several hours.
Objectives: To assess the change of the spectral
transmission after UV exposure (UV-challenged
protective performance) of 27 commercially available
photoprotective lipsticks.
Methods: Quartz slides were covered with a lipstick
layer (area density 1.0 0.1 mg/cm2) and irradiated
with increasing doses of solar-simulated radiation. The
spectral transmission (T) was measured spectrophotometrically before and after 5, 12.5, 25, and 50 standard
erythema doses (SED) of exposure. We calculated the
change in transmission (photoinstability) as the difference between the spectral transmission before and
after a defined UV exposure, DT, and the arithmetic
mean, for both the UVA (DTA) and UVB (DTB)
ranges. A product was labelled as photounstable if the
mean photoinstability in the UVA, DTA, or UVB
range, DTB, was higher than 5% for an UV exposure
of 12.5 SED.
Results: Eleven products showed a significant photoinstability in the UVA range (DTA between 6% and
27%), only one product in the UVB range (DTB 5
13%), and one product in both the UVA (DTA 5 31%)
and UVB (DTB 5 9%) range. In one product photoinstability became significant in the UVA range at
higher UV exposures.
Conclusions: Out of 27 lipsticks only 13 products
showed a photostable performance (DTAo5% and
DTBo5% for 12.5 SED). We propose therefore that
only products, which fulfil these UV photostability
criteria should be marketed.
T
data are available at present). Other risk factors
(pesticides) (14), engine exhaust fumes (15), immunosuppression (16–18), and a history of non-melanoma
skin cancer in other locations (19, 20, 21) increase the
susceptibility of the carcinogenic potential of solar
radiation (13, 22).
It has been shown that regular use of (photoprotective) lipsticks reduces lip cancer frequency (3). At
present, epidemiological data are available only for
farmers (3, 7–11). An issue of minor importance is
UV-induced herpes labialis. In an experimental
setting, relapse of herpes solaris could be prevented
in all patients who applied photoprotective lipsticks
before exposure to solar-simulated radiation (23).
Modern photoprotective lipsticks should therefore
fulfil the quality criteria that are demanded for
he importance of photoprotective lipsticks as
part of a comprehensive sun avoidance strategy
appears to be underestimated at present. For example,
in the report of the International Agency for Research
on Cancer (IARC) no recommendations concerning
the use of photoprotective lipsticks were included (1)
although it is well known that ultraviolet (UV)
radiation is a major risk factor for the development
of lip malignancies and premalignant labial lesions
(2–5). Because of the upright position of man the
vermilion of the lower lips receives the highest
irradiances of all facial regions (6). People who spend
a lot of time outdoors are therefore at an increased lip
cancer risk (3, 7–11) especially when they live and/or
work at places with low latitudes (2, 4, 12, 13) and/or
high above sea level (although no epidemiological
84
Key words: lipstick; photoinactivation; photoprotection; photostability; solar-simulated radiation; sunscreen; ultraviolet radiation; UV; UVA; UVB.
Ultraviolet Protective Performance of Photoprotective Lipsticks
modern sunscreens (lotions, creams) such as broadspectrum protection, high protective capacity for both
the UVB and the UVA range, and photostability.
Nevertheless, despite these criteria it has been shown
that, in a high percentage of commercially available
broad-spectrum sunscreens, the assessed UV protective performance does not correspond with the claims
made by the producers. The UV absorptive capacity
before UV exposure is not adequate (24–26) and many
sunscreens are significantly photounstable (26–32).
Until now, the UV protective performance of a
large number of commercially available photoprotective lipsticks has not been investigated. The objective
of our study was to assess the spectral behaviour of
photoprotective lipsticks after exposure to increasing
doses of solar-simulated UV radiation.
Materials and methods
Materials
We purchased 27 photoprotective lipsticks. Before
purchasing the products we conducted a market
analysis in order to select lipsticks which were widely
used among the population. The products of the first
series (a–p) were obtained in Austria while the
lipsticks of the second series (A–K) were products
available on the Italian market. The samples were
stored at room temperature and in the dark and
opened only immediately before the test procedure.
One sample of the same lot of each lipstick analysed
was stored under standardized conditions.
Experimental procedure
The spectrophotometric measurements of the UV
transmittance were conducted according to the
published in vitro test protocol (24), which we
modified in certain respects (26). In the present
investigation all lipsticks were applied onto quartz
glass slides as a layer of 1.0 0.1 mg/cm2 which is
only half of the area density (2.0 0.2 mg/cm2)
recommended by the COLIPA guidelines to measure
the sun protection factor (SPF) of sunscreens (33). We
decided to reduce the area density because our own
study (34) showed that in practice lipsticks are applied
in a much thinner layer than required by the COLIPA
guidelines. The application thickness will change the
absolute height of the absorbance curve but not its
shape. In this work changes in transmittance before
and after irradiation were evaluated; these differences
are independent of application thickness. Each
product was applied to a field of 10 cm2 on the quartz
slides by circular movements of a gloved finger. The
correct quantity was checked immediately after
application by a laboratory balance (with a resolution
of 0.01 mg). The samples were dried for 30 min at constant temperature (26 1C) and relative humidity
(50%), and then irradiated with a solar simulator
(COLIPA Dermasun Dr Hönle 400F/5, Dr Hönle
Lichttechnik GmbH, Planegg, Germany) at a radiometrically-defined homogeneous field of irradiance
(Solar Light SL 5D, Solar Light, Philadelphia, PA,
USA).
The biologically effective irradiance was 12.75
SED/h (SED, standard erythema dose; 1 SED 5
100 J/m2 of erythemally-effective radiation). An irradiance of 12.5 SED/h34 corresponds to an UV
index of 13.9, which can be expected even outdoors.
For a radiation time of 24, 59, 118, and 235 min we
obtained a radiant exposure of 5, 12.5, 25, and 50
SED. Under the assumption of a daily UV exposure
of about 75 SED (35) the maximum UV exposure of
50 SED would be equivalent to an exposure time of
about 2/3 of a day. The variability of the radiation
field (5.3%) was significantly below the COLIPA
guidelines (33). The spectral irradiance of the solar
simulator fulfilled the requirements of the COLIPA
guidelines (33) and is shown in Maier et al. (26).
Relative humidity (50%) and temperature (26 1C)
were kept constant during the entire irradiation time.
Two independent replicate samples of each product
were prepared and evaluated as described below. We
measured the spectral transmittance, Tl, for both the
UVB (280–320 nm) and the UVA range (320–380 nm)
before and after 5, 12.5, 25, and 50 SED of solarsimulated radiation with a resolution of 1 nm by
means of a UV/visible spectrophotometer (Varian
Cary 3E, Varian Australia Pty Ltd, Mulgrave,
Victoria, Australia) connected to an integrating
sphere (Labsphere DRA-CA-30, Labsphere, North
Sutton, NH, USA). In order to eliminate fluorescence
effects the sphere was armed with a Schott UG 11
filter (Schott, Mainz, Germany) (26). A tight-fitting
steel frame was added to the spectrophotometer
sample holder in order to keep the quartz slide in a
fixed position during the measurement procedure.
This guaranteed that a constant area of approximately 6 cm2 of the field on the quartz glass slide,
which was covered by the sun care product, was
illuminated (26). Furthermore, the sample could not
move during the measurement procedure because the
sample holder was screwed into the transmittance
sample port.
Data analysis
The change in the spectral transmittance of the
investigated lipsticks for a defined UV dose, D, at a
85
Maier et al.
particular wavelength l, DTl,D, was calculated from
the difference between the spectral transmittance
before UV exposure, Tl,0, and the spectral transmittance, Tl,D, for the defined UV dose, D (Eq 1) at that
wavelength. This value is called spectral photoinstability DTl,D.
DTl;D ¼ Tl;0 Tl;D :
ð1Þ
In addition to the spectral photoinstability, DTl,D,
the arithmetic mean of the DTl,D values for both the
UVA (320–380 nm), DTA, and the UVB (280–320 nm)
range, DTB, for UV doses of 5, 12.5, 25, and 50 SED
were calculated. We chose to describe the lipsticks as
photostable or photounstable in the UVA range
according to whether, at a dose of 12.5 SED, DTA
was less than, or greater than or equal to, 5%,
respectively. The same rule was applied in the UVB
range. This limit value of 5% was selected arbitrarily.
Results
Characterization of photoprotective lipsticks
The information that appeared on the labels of the 27
photoprotective lipsticks investigated is collected in
Table 1. In 23 products broad-spectrum protection
was claimed on the package, either by labelling UVB
and UVA protection or by the use of the word block.
In four products (d, i, m, and K) no broad-spectrum
protection was claimed. The SPF value was given for
21 of the products. Surprisingly, for six lipsticks (B, E,
G, H, J, and K) no indication of the SPF was
provided. Although the method of assessing the UVA
protection factor was shown in only two products (n,
D), which were produced by the same company, a
UVA protection factor was shown on none of the lipsticks. For all but four lipsticks (g, i, F, and G) a list
of the sunscreen active ingredients was available. Four
lipsticks contained one UV filter, nine lipsticks two
UV filters, five products contained three, and another
five contained four different UV filters (inorganic
filters included). A total of 13 different filter combinations could be identified. The most common UV filter
combinations were: titanium dioxide (TiO2), methylbenzylidene camphor (MBC), octyl methoxycinnamate (OMC) and butyl methoxydibenzoylmethane
(BMDBM) in three products; OMC and BMDBM
(four products); and OMC and an inorganic filter
(either TiO2 or ZnO) in another three products.
Change in spectral transmittance because of
UV exposure
In order to distinguish between photostable and photounstable products we selected a mean photoinst-
86
Table 1. Details of the photoprotective lipsticks investigated.
Products a–p were available on the Austrian market and products
A–K were available on the Italian market
Broad-spectrum
protection
Suncare Made
SPF labelledw
UV filtersz
product inn
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
A
B
C
D
E
F
G
H
I
J
K
D
D
D
F
S
F
E
B
D
D
D
UK
ND
CH
ND
USA
F
F
I
CH
I
Mon
I
I
F
I
I
10
25
18
4
7
15
20
15
15
15
12
20
4
20
16
15
25
ND
10
20
ND
30
ND
ND
30
ND
ND
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
OMC, MBC, BMDBM
TiO2, OMC, MBC, BMDBM
TiO2, OMC, MBC, BMDBM
OMC
BP, ODM-PABA
BP
ND
OMC, OS
ND
BP, OMC, BMDBM
TiO2, MBC, IAMC
TiO2, OMC, MBC, BMDBM
OMC
ZnO, TiO2, OMC, BMDBM
OS, OT, MBC, BMDBM
TiO2, OMC
TiO2, OMC
TiO2, OMC, BMDBM
ZnO, OMC
OMC, MBC, BMDBM
OMC, BMDBM
ND
ND
OMC, BMDBM
BP
OMC, BMDBM
OMC, BMDBM
Photounstable products, shown in bold; SPF, sun protection factor;
ND, not declared.
n
postal code for country.
wUVB/UVA protective capacity declared on package or product
name containing the word ‘‘block’’.
zabbreviations for UV filters: BP, benzophenone-3 (oxybenzone);
BMDBM, butyl methoxydibenzoylmethane (avobenzone); IAMC,
isoamyl p-methoxycinnamate; MBC, methylbenzylidene camphor;
ODM-PABA, octyl dimethyl para-aminobenzoic acid (padimate-O);
OMC, octyl methoxycinnamate; OS, octyl salicylate; OT, octyl
triazone; TiO2, titanium dioxide; ZnO, zinc oxide; UV, ultraviolet.
ability of 5% for an UV exposure of 12.5 SED either
in the UVB (DTB) or in the UVA range (DTA) as the
threshold value (Table 2). This UV exposure corresponds to a minimal erythemal dose (MED) for skin
type II (1 MED 5 250 J/m2 of erythemally-effective
UV radiation) of about five MED, which is a realistic
value for the application of a lipstick. In the case of 11
lipsticks (a, b, c, j, n, B, E, G, H, J, and K),
photoinstability in the UVA range, DTA, for 12.5
SED was significantly above 5%, whereas only one
lipstick (m) exhibited photoinstability in the UVB
range, DTB, and one product (l) showed photoinstability in both spectral ranges above the threshold
value of 5%. Lipstick D (DTA for 12.5 SED 5 4.4%)
showed significant photoinstability in the UVA range
with higher UV doses and is therefore also regarded
Ultraviolet Protective Performance of Photoprotective Lipsticks
Table 2. Mean photoinstability in the UVA (320–380 nm) range, DTA (%), and the UVB (280–320 nm) range, DTB (%), for an UV exposure of
5, 12.5, 25, and 50 SEDn
Mean photoinstability (%) in the UVA and in the UVB range for different UV exposures (in SED)
UV exposure (in SEDn)
50
12.5w
25
50
Lipstick
DTB
DTA
DTB
DTA
DTB
DTA
DTB
DTA
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
A
B
C
D
E
F
G
H
I
J
K
0.04
0.05
0.21
0.94
0.16
0.03
0.05
0.94
0.33
0.08
0.36
1.52
8.07
0.87
0.17
0.81
0.18
0.38
1.38
0.05
2.23
0.06
0.88
0.12
0.03
1.33
1.39
3.01
6.28
9.98
0.65
0.84
0.27
0.60
2.97
1.45
4.07
2.08
9.87
1.65
16.50
0.69
2.03
0.02
1.38
0.98
1.17
9.92
0.07
4.20
5.76
0.38
7.11
3.20
0.91
0.97
0.64
1.63
0.07
0.01
0.63
2.29
0.44
0.21
0.53
8.72
13.34
1.49
0.21
1.04
0.30
1.04
1.81
0.08
3.36
0.04
2.78
0.39
0.06
4.07
3.48
15.01
18.87
20.59
1.09
1.13
0.21
0.16
2.29
0.30
12.94
1.85
30.77
3.73
19.98
1.77
2.42
0.06
5.93
1.23
4.41
26.84
0.02
17.64
26.21
0.58
24.74
10.21
0.98
1.44
1.00
2.04
0.01
0.15
0.58
4.06
0.46
0.07
0.75
10.69
12.83
2.29
0.34
1.73
0.31
2.40
2.66
0.19
5.26
0.03
5.77
1.06
0.05
6.21
6.27
31.35
26.76
25.33
1.87
0.52
1.41
2.02
0.70
0.27
18.61
1.70
44.33
3.70
20.57
4.16
1.10
0.07
19.89
2.05
12.16
46.19
0.14
43.23
53.75
0.84
41.09
26.06
1.06
1.77
1.58
3.74
0.38
0.12
0.29
9.62
0.79
0.25
1.26
13.04
17.06
4.71
0.45
4.26
0.52
8.21
4.04
0.28
9.19
0.02
12.03
2.70
0.10
10.31
12.29
48.66
27.99
27.03
1.62
0.34
1.14
7.11
3.45
0.51
21.75
0.86
48.28
5.18
22.67
7.66
1.40
0.80
51.38
3.74
34.69
51.99
0.48
57.97
63.00
1.08
49.56
52.83
Products a–p were available on the Austrian market and products A–K were available on the Italian market
n
SED, standard erythema dose; UV, ultraviolet.
wA photoinstability of 5% for an UV exposure of 12.5 SED was used to distinguish between photostable and photounstable products
(shown in bold).
(but not labelled in the tables) as a photounstable
product. In addition to products l and m with
significant instability in the UVB range, several
lipsticks (E, G, J, and K) showed an increase in the
UVB transmittance of about 3–4%. In these four
products a moderate photoinstability in the UVB
range was induced by higher UV exposures (Table 2).
For UV exposures of 5, 12.5, 25, and 50 SED,
respectively, the numbers of photounstable products
were 8, 13, 14, and 17. Photoinstability in both
wavelength ranges of all photounstable lipsticks
increased with UV dose. The change in spectral
transmittance (here referred to as spectral photoinstability) for a UV exposure of 12.5 SED is depicted in
Fig. 1 for the photostable lipsticks and in Fig. 2 for
the photounstable products. This is the UV exposure,
which was used to distinguish between photounstable
products (Table 2, DTA45% or DTB45% highlighted in bold) and photostable products. Most
photounstable products show a steep increase in the
spectral photoinstability in the range between 330 and
350 nm, except for product j, which shows an increase
beyond 350 nm.
UV protective performance and UV filter system
We correlated the UV protective performance of the
lipsticks investigated with the UV filter substances
(Table 1). Seven combinations of UV filters (either
singly or in combination) were present in the 14
photounstable products of our test series. These
ranged from one active ingredient present to four.
For one unstable product (G) the active ingredients
were not specified.
What is evident is that all lipsticks, which contain
the UV filter combination BMDBM and OMC,
irrespective of the other active sunscreen ingredients,
are unstable. Only one photostable product (o) contained BMDBM, but not in combination with OMC.
Apart from products d and m, all other identical filter
combinations exhibited the same behaviour. Products
87
Maier et al.
50
45
Spectral Photoinstability ∆T (%)
40
35
30
25
a
d
e
f
g
h
i
k
o
p
20
12.5 SED
50
45
40
UVB
Spectral Photoinstability ∆T (%)
a
UVA
15
10
5
0
-5
35
30
a
b
c
j
l
m
n
12.5 SED
25
20
15
UVB
10
0
-5
-10
280 290 300 310 320 330 340 350 360 370 380 390
-10
280 290 300 310 320 330 340 350 360 370 380 390
Wavelength λ (nm)
50
45
Spectral Photoinstability ∆T (%)
40
35
A
C
D
F
I
Wavelength λ (nm)
12.5 SED
45
40
30
25
20
15
10
b 50
UVB
UVA
5
0
Spectral Photoinstability ∆T (%)
b
UVA
5
35
B
E
G
H
J
K
12.5 SED
30
25
20
15
10
UVB
UVA
5
0
-5
-5
-10
280 290 300 310 320 330 340 350 360 370 380 390
Wavelength λ (nm)
-10
280 290 300 310 320 330 340 350 360 370 380 390
Wavelength λ (nm)
Fig. 1. Photostable photoprotective lipsticks on the
Austrian market (a) and the Italian market (b) shown
by the spectral photoinstability DTl for an ultraviolet
(UV) exposure of 12.5 standard erythema doses
(SED). The photounstable products were selected
based on a mean photoinstability DT in the UVB
or in the UVA range of equal to or greater than 5%
(thin line).
Fig. 2. Photounstable photoprotective lipsticks on the
Austrian market (a) and the Italian market (b) shown
by the spectral photoinstability DTl for an ultraviolet
(UV) exposure of 12.5 standard erythema doses
(SED). The photounstable products were selected
based on a mean photoinstability DT in the UVB
or in the UVA range of equal to or greater than 5%
(thin line).
d and m contained the same UV filter, namely OMC,
but d was photostable and m was photounstable.
The spectral transmittance curves (Figs 1 and 2) for
lipsticks with the same UV filters in the formulation
are essentially the same in shape but are shifted on the
y-axis because of different amounts of the active
substances in each formulation.
which these compounds absorb radiant energy. A
significant body of research exists that describes the
photoinstability of single UV filters (31, 36–42) and
demonstrates the change in the spectral absorbance
(39, 40) which occurs on UV exposure, as well as
identifying the resulting photolysis products (37, 39–
42). A modern suncare product consists of a number
of different ingredients besides UV filters and vehicles
(43). Photochemical reactions between excited UV
filter molecules and other sunscreen ingredients are
therefore highly likely. There are only few studies,
however, which assess the UV behaviour of finished
sunscreening products (26–30, 32). To the best of our
Discussion
Photoinstability of sunscreen active ingredients is a
well-known phenomenon (31, 32, 36–42), which is
closely related to the photophysical mechanism by
88
Ultraviolet Protective Performance of Photoprotective Lipsticks
knowledge this study is the first report on the
photostability of a representative sample of commercially available photoprotective lipsticks.
Sunscreen producers attempt to stabilize sunscreen
formulations by using complex combinations of
organic and inorganic UV filters (44), and the
addition of stabilizers (45, 46). Our study, which is
in agreement with the results of our previous work
(26) and of other study groups (27–30, 32), shows that
these methods are not always successful. Furthermore, our present study confirms the findings of our
previous work (26) and of other working groups (27,
29, 30, 32) that inorganic filters as part of the filter
system do not guarantee photostability. The addition
of TiO2 may accelerate photodegradation of organic
UV filters, and even sunscreens which contain only
inorganic compounds may show significant photoinstability (32). In contrast to the UV behaviour of the
sunscreens of our previous test series (26) in which
some of the sunscreens with a particular UV filter
combination were photounstable whereas other products which contained identical filters were photostable, all lipsticks other than d and m with identical
filter combinations showed a unidirectional performance. This is not a discrepancy but emphasizes the
importance of solvent vehicle and type of emulsion
(W/O, O/W) (47–49). It has been shown that the
photostability behaviour changes significantly in
solvents with different polarity (32, 37, 49).
Photoprotective lipsticks are ideal study objects for
photostability tests. First, because of their solid
consistency and low water content they can be applied
in a homogeneous layer, which may not be possible
for other photoprotective preparations, such as
creams and lotions (50–52). Second, in all of them
the active ingredients are dissolved in an oily phase
(O). The use of one type of emulsion (O) appears to be
the reason why lipsticks, which contain identical
filters show the same UV behaviour.
In our previous study (26) photoinstability could be
demonstrated only for the UVA range whereas all
sunscreens were photostable in the UVB range. In the
present test series of lipsticks, however, 12 products
were photounstable in the UVA range, one lipstick
showed a significant photoinstability in the UVB
range, and one was photounstable in both the UVB
and the UVA range. This corresponds with the results
of other studies, which show that photoinstability
occurs in both the UVA and UVB ranges, and that
photoinstability is more significant in the UVA range
(27–29, 32). All these investigations indicate that
photoinstability is a common phenomenon in sunscreening products, which can be purchased over the
counter (26, 27, 29, 30, 32), and is induced by UV
exposures of a magnitude which can easily be
acquired by sunbathers (26–30).
It is interesting to note that all lipsticks containing
the UV filter combination BMDBM and OMC,
irrespective of the other active sunscreen ingredients,
are photounstable. It is well-known that BMDBM
undergoes photodegradation in a non-polar environment (39), such as the oily phases used in lipsticks,
and that in all environments OMC undergoes trans-cis
photoisomerization and thereby loses some of its
absorbing ability. In combination BMDBM can further photodegrade OMC as it can act as a photosensitizer to the photoisomerization reaction (27, 49).
BMDBM is one of the few organic sunscreening
agents, which afford particular protection in the
longwave UVA range. It absorbs maximally at about
356 nm and its photoinstability can be seen in the
sharp increase in spectral photoinstability between
330 and 350 nm exhibited by the photounstable
products. The fact that product j, although unstable,
shows this rapid change at a longer wavelength can be
accounted for by the fact that it contains benzophenone-3 (oxybenzone), a photostable absorber, which
absorbs in the short wavelength UVA region and
hence masks part of the BMDBM photoloss.
Although products d and m are apparently identical
in terms of UV filter (only OMC) and SPF they
behaved differently. Neither of these products can
afford UVA protection as they do not contain a UVA
filter, but the change in spectral photoinstability for
product m can be explained by the fact that, upon UV
irradiation, OMC photoisomerizes to its cis-isomer
which is a less efficient absorber of UVB radiation.
Why this did not occur with product d is not evident,
but it emphasizes the importance of the vehicle, since
OMC in different suncare products has been shown to
lose between 20% and 46% of its absorptive capacity
for the same UV exposure of 12 J/cm2 (30).
We are far from supporting sunscreen phobia
‘which has captured the imagination of popular press’
(53). Beyond doubt, the benefit achieved through the
use of modern sunscreens of high quality far outweighs the damage because of unprotected UV
exposure. However, there is strong evidence that
photounstable UV filters may be harmful to human
skin. Two mechanisms, that in the end are closely
related, have been described. First, the decrease of the
absorptive capacity because of photoinstability of the
absorbers results in an increase of the transmitted
radiation and in many cases this happens to be UVA
radiation (54), as was shown in this work. The
transmittance of great amounts of UVA radiation
89
Maier et al.
may at first sight appear to be inconsequential if one
considers the reference action spectrum for UVinduced erythema and the estimated action spectrum
for induction of squamous cell carcinomas by UV in
the skin of hairless mice (55), since the erythemogenic
and carcinogenic effect of a transmitted UVB dose is
much more pronounced than the biological effect of a
transmitted UVA dose. Furthermore, a recent publication indicated that the vermilion of human lips
appears to be less UV-sensitive than the skin in other
areas of the body (56). Nevertheless, both UVB and
UVA were defined as carcinogenic factors by the
IARC (57) and sub-erythemogenic UVA doses are
responsible for various biological effects, e.g., induction of photosensitivity diseases (58) and skin photodamage (59). Second, as a result of photochemical
reactions short-lived reactive products form which
may react with biomolecules (60–63) and give rise to
potentially mutagenic products.
The practical relevance of these in vitro studies and
the possible health risks induced by photounstable
UV filters is not obvious at present. Until an action
spectrum for photoaging has been defined, the
damaging effect cannot be quantified. Lipsticks are
among the most common causes of acute contact
cheilitis (64), with UV filters (65) taking third place as
causative agents in a retrospective analysis (64). To
our knowledge, photoallergic/phototoxic reactions of
lip skin have until now not been described. The
question of whether photoallergic/phototoxic cheilitis
is really a rare disease or only rarely diagnosed is
unanswered at present.
The surprisingly bad UV protective performance of
commercially available photoprotective lipsticks calls
for rigorous guidelines. A specification of the relevant
properties of purchasable sunscreens (SPF, UVA
protection factor, method of assessment of UVA
protection factor, photostability test, complete list of
ingredients and amounts of UV filters) should be a
minimal requirement. It goes without saying that the
labelled features should be demonstrable in reality.
There are several good reasons for these demands:
firstly, sunscreen producers are subject to product
liability; secondly, sunscreens should meet the challenge they are constructed for; thirdly, consumers
should not be lulled into a false sense of security;
fourthly, photostable products are already available
on the market and there is no reason to tolerate
sunscreens with insufficient UV protective performance. Our final suggestion is specific to photoprotective lipsticks. International health authorities, e.g.
the IARC, should include a recommendation for
regular photoprotective lipstick use in the guidelines
90
as a valuable part of a comprehensive sun avoidance
strategy especially for people with increased risk for
the development of lip malignancies, such as outdoor
workers (7–11) and transplant recipients (16, 17).
Acknowledgements
The authors thank Alexander Cabaj, Institute of
Medical Physics and Biostatistics, University of
Veterinary Medicine Vienna, for critical discussion
of the manuscript and CERIES for financial support.
BSM wishes to acknowledge financial support from
the National Research Foundation and the Cancer
Association of South Africa.
References
1. Vainio H, Miller AB, Bianchini F. An international evaluation
of the cancer-preventive potential of sunscreens. Int J Cancer
2000; 88: 838–842.
2. Moore SR, Allister J, Roder D, Pierce AM, Wilson DF. Lip
cancer in South Australia, 1977–1996. Pathology 2001; 33:
167–171.
3. Pogoda JM, Preston-Martin S. Solar radiation, lip protection,
and lip cancer risk in Los Angeles county women (California,
United States). Cancer Causes Control 1996; 7: 458–463.
4. Swerdlow AJ, Cooke KR, Skegg DC, Wilkinson J. Cancer incidence in England and Wales and New Zealand and in migrants
between the two countries. Br J Cancer 1995; 72: 236–243.
5. Lyon JL, Gardner K, Gress RE. Cancer incidence among
Mormons and non-Mormons in Utah (United States) 1971–85.
Cancer Causes Control 1994; 5: 149–156.
6. Schauberger G, Keck G. Beitrag zur Bestimmung der solaren
UV Belastung der Haut: eine epidemiologische Betrachtung zur Ätiologie des Basalioms. Aktuel Dermatol 1990; 11:
289–328.
7. Khuder SA. Etiologic clues to lip cancer from epidemiologic
studies on farmers. Scand J Work Environ Health 1999; 25:
125–130.
8. Cerhan JR, Cantor KP, Williamson K, Lynch CF, Torner JC,
Burmeister LF. Cancer mortality among Iowa farmers: recent
results, time trends and life style factors (United States).
Cancer Causes Control 1998; 9: 311–319.
9. Schouten LJ, Meijer H, Huveneers JA, Kiemeney LA. Urban–
rural differences in cancer incidence in the Netherlands 1989–
1991. Int J Epidemiol 1996; 25: 729–736.
10. Wiklund K, Dich J. Cancer risks among male farmers in
Sweden. Eur J Cancer Prev 1995; 4: 81–90.
11. Fincham SM, Hanson J, Berkel J. Patterns and risks of cancer
in farmers in Alberta. Cancer 1992; 69: 1276–1285.
12. Lookingbill DF, Lookingbill GL, Leppard B. Actinic damage
and skin cancer in albinos in northern Tanzania: findings in
164 patients enrolled in an outreach skin care program. J Am
Acad Dermatol 1995; 32: 653–658.
13. Dardanoni L, Gafa L, Paterno R, Pavone G. A case-control
study on lip cancer risk factors in Ragusa (Sicily). Int J Cancer
1984; 34: 335–337.
14. Davies DL, Blair A, Hoel DG. Agricultural exposures and
cancer trends in developed countries. Environ Health Perspect
1993; 100: 39–40.
15. van den Eeden SK, Friedman GD. Exposure to engine exhaust
and risk of subsequent cancer. J Occup Med 1993; 35: 307–311.
16. Jensen P, Hansen S, Moller B, et al. Skin cancer in kidney and
heart transplant recipients and different long-term immuno-
Ultraviolet Protective Performance of Photoprotective Lipsticks
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
suppressive therapy regimens. J Am Acad Dermatol 1999; 40:
177–186.
King GN, Healy CM, Glover MT, et al. Increased prevalence
of dysplastic and malignant lip lesions in renal transplant
recipients. N Engl J Med 1995; 332: 1052–1057.
Birkeland SA, Storm HH, Lamm LU, et al. Cancer risk after
renal transplantation in Nordic countries, 1964–1986. Int J
Cancer 1995; 60: 183–189.
Wassberg C, Thorn M, Yuen J, Ringborg U, Hakulinen T.
Second primary cancers in patients with squamous cell
carcinoma of the skin: a population-based study in Sweden.
Int J Cancer 1999; 80: 511–515.
Frisch M, Hjalgrim H, Olsen JH, Melbye M. Risk for
subsequent cancer after diagnosis of basal cell carcinoma. A
population based, epidemiologic study. Ann Intern Med 1996;
125: 815–821.
Jaeger AB, Gramkow A, Hjalgrim H, Melbye M, Frisch M.
Bowen disease and risk of subsequent malignant neoplasms:
a population-based cohort study of 1147 patients. Arch
Dermatol 1999; 135: 790–793.
Preston-Martin S, Henderson BE, Pike MC. Descriptive
epidemiology of cancers of the upper respiratory tract in Los
Angeles. Cancer 1982; 49: 2201–2207.
Rooney JF, Bryson Y, Mannix ML, et al. Prevention of
ultraviolet-light-induced herpes labialis by sunscreen. Lancet
1991; 338: 1419–1422.
Marginean G, Fructus AE, Marty JP, Arnaud-Battandier J.
New ex-vivo method for evaluating the photoprotective efficacy
of sunscreens. Int J Cosmet Sci 1995; 17: 233–243.
Diffey BL, Tanner PR, Matts PJ, Nash JF. In vitro assessment
of the broad-spectrum ultraviolet protection of sunscreen
products. J Am Acad Dermatol 2000; 43: 1024–1035.
Maier H, Schauberger G, Brunnhofer K, Hönigsmann H.
Change of ultraviolet absorbance of sunscreens by exposure
to solar-simulated radiation. J Invest Dermatol 2001; 117:
256–262.
Sayre RM, Dowdy JC. Photostability testing of avobenzone.
Cosmet Toil 1999; 114: 85–91.
Kockott D. In vitro Bewertung von Sonnenschutzmitteln.
Kosmetische Med 1998; 19: 290–293.
Diffey BL, Stokes RP, Forestier S, Mazalier C, Rougier A.
Suncare product photostability: a key parameter for a more
realistic in vitro efficacy evaluation. Eur J Dermatol 1997; 7:
226–228.
Forestier S, Mazalier C, Rougier A. Suncare product photostability: a key parameter for a more realistic in vitro efficacy
evaluation. Part II: chromatographic analysis. Eur J Dermatol
1997; 7: 6–8.
Jiang R, Hayden CG, Prankerd RJ, Roberts MS, Benson HA.
High-performance liquid chromatography assay for common
sunscreening agents in cosmetic products, bovine serum
albumin solution and human plasma. J Chromatogr B 1996;
682: 137–145.
Serpone N, Salinaro A, Emeline AV, Horikoshi S, Hidaka H,
Zhao J. An in vitro systematic spectroscopic examination of the
photostabilities of a random set of commercial sunscreen
lotions and their chemical UVB/UVA active agents. Photochem Photobiol Sci 2002; 1: 970–981.
COLIPA (European Cosmetic Toiletry and Perfumery Association). SPF test method. Brussels: COLIPA, 1994.
Maier H, Schauberger G, Brunnhofer K, Hönigmann H.
Assessment of thickness of photoprotective lipsticks and
frequency of reapplication: results from a laboratory test and
a field experiment. Br J Dermatol 2002; 148: 763–769.
Schmalwieser AW, Schauberger G, Janouch M, et al. Global
validation of a forecast model for irradiance of the solar, erythemally effective ultraviolet radiation. Opt Eng 2002; 41:
3040–3050.
36. Vanquerp V, Rodriguez C, Coiffard C, Coiffard LJ, De RoeckHoltzhauer Y. High-performance liquid chromatographic
method for the comparison of the photostability of five sunscreen agents. J Chromatogr 1999; 832: 273–277.
37. Tarras-Wahlberg N, Stenhagen G, Larkö O, Rosen A, Wennberg AM, Wennerström O. Change in ultraviolet absorption
of sunscreens after ultraviolet irradiation. J Invest Dermatol
1999; 113: 547–553.
38. Berset G, Gonzenbach H, Christ R, et al. Proposed protocol
for determination of photostability Part I. Cosmetic UV filters.
Int J Cosmet Sci 1996; 18: 167–177.
39. Schwack W, Rudolph T. Photochemistry of dibenzoylmethane
UVA filters Part I. J Photochem Photobiol B 1995; 28: 229–234.
40. Roscher NM, Lindemann MKO, Kong SB, Cho GC, Jiang P.
Photodecomposition of several compounds commonly used as
sunscreen agents. J Photochem Photobiol A 1994; 80: 417–421.
41. Gasparro FP. UV-induced photoproducts of para-aminobenzoic acid. Photodermatology 1985; 2: 151–157.
42. Chignell CF, Kalyanaraman B, Mason RP, Sik RH. Spectroscopic studies of cutaneous photosensitizing agents-I. Spin
trapping of photolysis products from sulphonamide, 4aminobenzoic acid and related compounds. Photochem Photobiol 1980; 32: 563–571.
43. Klein K. Sunscreen products. Formulation and regulatory
considerations. In: Lowe NJ, Shaath NA, Pathak MA, eds.
Sunscreens, development, evaluation, and regulatory aspects,
2nd edn. New York: Marcel Dekker, 1997; 285–311.
44. Chatelain E, Gabard B. Photostabilization of butyl methoxydibenzoylmethane (Avobenzone) and ethylhexyl methoxycinnamate by bis-ethylhexyloxyphenol methoxyphenyl triazine
(Tinosorb S), a new UV broadband filter. Photochem Photobiol 2001; 74: 401–406.
45. Scalia S, Villani S, Casolari A. Inclusion complexation of the
sunscreen agent 2-ethyl hexyl-p-dimethylaminobenzoate with
hydroxypropyl-(beta)-cyclodextrin: effect on photostability.
J Pharm Pharmacol 1999; 51: 1367–1374.
46. Bonda C, Steinberg DC. A new photostabilizer for full
spectrum sunscreens. Cosmet Toil 2000; 115: 37–45.
47. Agrapidis-Paloympis LE, Nash RA, Shath NA. The effect of
solvents on the ultraviolet absorbance of sunscreens. J Soc
Cosmet Chem 1987; 38: 209–211.
48. Marti-Mestres G, Fernandez C, Parsotam N, Nielloud F,
Mestres JP, Maillois H. Stability of UV filters in different
vehicles: solvents and emulsions. Drug Dev Ind Pharm 1997;
23: 647–655.
49. Panday R. A photochemical investigation of two sunscreen
absorbers in a polar and a non-polar medium. MSc thesis,
Durban, South Africa: University of Natal. 2003
50. Lott DL, Stanfield J, Sayre RM, Dowdy JC. Uniformity of
sunscreen product application: a problem in testing, a problem
for consumers. Photodermatol Photoimunol Photomed 2003;
19: 17–20.
51. Grencis PW, Stokes R. An evaluation of photographic
methods to demonstrate the uniformity of sunscreen applied
to the skin. J Audiov Media Med 1999; 22: 171–177.
52. Loesch H, Kaplan DL. Pitfalls in sunscreen application. Arch
Dermatol 1994; 130: 665–666.
53. Nohynek GJ, Schaefer H. Benefit and risk of organic ultraviolet filters. Regul Toxicol Pharmacol 2001; 33: 285–299.
54. Moyal D, Refregier JL, Chardon A. In vivo measurement of
the photostability of sunscreen products using diffuse reflectance spectroscopy. Photodermatol Photoimmunol Photomed
2002; 18: 14–22.
55. deGruijl FR, Sterenborg HJCM, Forbes PD, et al. Wavelength
dependence of skin cancer induction by ultraviolet radiation of
albino hairless mice. Cancer Res 1993; 53: 53–60.
56. Gabard B, Ademola J. Lip sun protection factor of a lipstick
sunscreen. Dermatology 2001; 203: 244–247.
91
Maier et al.
57. IARC (International Agency for Research on Cancer). Solar
and ultraviolet radiation. Monographs on the evaluation of
carcinogenic risks to humans; vol. 55. Lyon: IARC, WHO,
1992.
58. Duguid C, O’Sullivan D, Murphy GM. Determination of
threshold UVA elicitation dose in photopatch testing. Contact
Dermatitis 1993; 29: 192–194.
59. Lavker R, Kaidberg F. The spectral dependence for UVAinduced cumulative damage in human skin. J Invest Dermatol
1997; 108: 17–21.
60. Damiani E, Carloni P, Biondi C, Greci L. Increased oxidative
modification of albumin when illuminated in vitro in the
presence of a common sunscreen ingredient: protection by
nitroxide radicals. Free Radic Biol Med 2000; 28: 193–201.
61. McHugh PJ, Knowland J. Characterization of DNA damage
inflicted by free radicals from a mutagenic sunscreen ingredient
and its location using an in vitro genetic reversion assay.
Photochem Photobiol 1997; 66: 276–281.
62. Schallreuter KU, Wood JM, Farwell DW, Moore J, Edwards
HG. Oxybenzone oxidation following solar irradiation of skin:
photoprotection versus antioxidant inactivation. J Invest
Dermatol 1996; 106: 583–586.
63. Dogra A, Minocha YC, Sood VK, Dewan SP. Contact dermatitis due to cosmetics and their ingredients. Ind J Dermatol
Venereol Leprol 1994; 60: 72–75.
92
64. Freeman S, Stephens R. Cheilitis: analysis of 75 cases referred
to a contact dermatitis clinic. Am J Contact Dermatitis 1999;
10: 198–200.
65. Aguirre A, Izu R, Gardeazabal J, Gil N, Diaz-Perez JL.
Allergic contact cheilitis from a lipstick containing oxybenzone. Contact Dermatitis 1992; 27: 267–268.
Accepted for publication 1 December 2004
Corresponding author:
Harald Maier, M.D.
Division of Special and Environmental Dermatology
Medical University of Vienna
Währinger Gürtel 18–20
A-1090 Vienna
Austria
Tel: 143 1 4060866
Fax: 143 1 4081278
e-mail: harald.maier@meduniwien.ac.at