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WHAT'S
THAT STUFF?
SUNSCREENS
Active ingredients prevent skin
damage
It
was decades ago when I had time to lounge
poolside for hours on end, but I do remember
roasting myself in the sun for a healthy tan,
basting my body with oils to enhance the
effect.
Times have changed. We've
always known that sun can burn our skin. But now
we also know that long exposure to the sun's
ultraviolet rays can prematurely age skin and
ultimately lead to skin cancer. Add to those
worries the depletion of upper atmospheric
ozone: As a result, we are all likely to get an
even higher dose of UV light during our time
outdoors than during the days when I was a pool
lizard.
And that healthy tan? It's
really not so healthy after all. "A tan is
the body's reaction to damage," Coty Senior
Vice President of R&D Ralph Macchio says.
"But you don't have to limit your fun in
the sun if you use a good sunscreen."
It's no surprise then that
sunscreen sales to beach and pool goers are on
the rise. And active sunscreen ingredients are
also finding their way into a variety of
daily-use personal care products, such as
moisturizers, eyeshadow, foundations, and
lipsticks. Annual sunscreen actives sales in the
U.S. and Europe are each about $100 million and
are likely to grow 4% annually through 2006,
according to industry consultant Kline & Co.
Sunscreens have not always
been so prevalent. The first commercial
sunscreens came out during World War II, when
U.S. sailors used zinc oxide preparations to
prevent sunburn. The general public picked up
the practice in the 1950s and 1960s. I can
remember some veterans sitting on the beach in
the 1960s sporting a white blob of the stuff on
their nose.
Companies such as Givaudan, a
Roche division spun off in 2000, began to
develop organic sunscreens in the late '60s, as
they looked for a sunscreen that wouldn't leave
a white haze on the skin. Then scientists
started to become concerned about UV light's
effects on skin.
Today, there are 17 sunscreen
active ingredients approved for use in the U.S.
and 25 approved for use in Europe. What's a body
to use?
THERE
ARE TWO basic types of
active ingredients: inorganic and organic. Both
afford protection against UV-B rays in the 280-
to 320-nm range, the primary culprits in
sunburn. Some offer additional protection from
UV-A rays in the 320- to 400-nm range, which can
penetrate more deeply into the skin and do
greater long-term damage.
Inorganic sunscreens use
titanium dioxide and zinc oxide. They work
primarily by reflecting and scattering UV light.
The organics include widely used ingredients
such as octyl methoxycinnamate (OMC),
4-methylbenzylidene camphor (4-MBC), avobenzone,
oxybenzone, and homosalate. They work primarily
by absorbing UV light and dissipating it as
heat.
Formulators often combine
inorganic and organic sunscreens for a
synergistic effect. In fact, that is how most
are capable of achieving very high SPF--sun
protection factor--ratings. SPF is a measure of
how effectively a sunscreen in a formulation
limits skin exposure to the UV-B rays that burn
skin. The higher the number, the more protection
a sunscreen formula affords against sunburn.
However, the SPF system does
not provide an objective measure of protection
against UV-A radiation. And although sunscreen
formulators do say their products contain
broad-spectrum protection, a U.S. consumer has
no clear way to compare the UV-A protection
offered by one product with another. Europe has
an unofficial method, whereas Japan and Korea
have a system in place.
Among the inorganics, zinc
oxide offers much better UV-A protection than
TiO2. Among the U.S.-approved
organics, avobenzone offers the greatest UV-A
protection, but others offer some protection as
well, depending on their absorption spectrum.
A problem with inorganics is
that they may leave a haze on the skin.
Generally, the oil in a sunscreen formula helps
wet the inorganic particles and gives the
optical effect of transparency. But use of a
formula with high levels of TiO2
could remind you of that veteran with the white
blob on his nose.
However, cosmetic ingredients
supplier Uniqema says its newest TiO2
won't have that problem. Its new Solaveil Clarus
line has a particle size distribution between 40
and 50 nm, offering not only good UV protection
but also avoiding the occurrence of large
particles that give a whitening effect.
There are other ways around the problem.
According to Gabriel E. Uzunian, Engelhard's
director of cosmetic applications, a red
interference pigment added to a sunscreen
formula can counteract the whitening effect. The
TiO2-coated mica pigment complements
and enhances light skin tones and gives a more
"natural" appearance to a beach
sunscreen, Uzunian says.
Recent scientific work by
environmental toxicologist Margaret Schlumpf and
colleagues at the University of Zurich's
Institute of Pharmacology & Toxicology
suggests that OMC and 4-MBC--two widely used
organic sunscreens--are potential endocrine
disrupters. But industry research and government
advisory committee reviews have disputed the
work. The Food & Drug Administration still
approves OMC for use in the U.S., though it
never approved 4-MBC. The European Union's
Scientific Committee for Cosmetic Products &
Non-Food Products continues to approve OMC and
4-MBC.
So what is a body to do?
"Everyone goes with safety," notes
Karl Harris, Haarmann & Reimer's director of
cosmetic ingredients. "I know of no one not
using OMC, but some in Europe are taking a
closer look at 4-MBC."
It all makes you think that
people who have lived in the desert intuitively
know something we sun worshipers never learned:
It may not be a bad idea at all to wrap yourself
in white, light-reflecting robes, especially at
the beach. Otherwise, do choose a sunscreen with
UV-A and UV-B protection--and wear
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