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What is an SPF?
The Sun Protection Factor (SPF) displayed on the sunscreen label
ranges from 2 to as high as 50 and refers to the product's ability
to screen or block out the sun's harmful rays. For example, if you
use a sunscreen with an SPF 15, you can be in the sun 15 times longer
that you can without sunscreen before burning. Consumers need to
be aware that SPF protection does not increase proportionally with
an increased SPF number. While an SPF of 2 will absorb 50% of ultraviolet
radiation, an SPF of 15 absorbs 93% and an SPF of 34 absorbs 97%.
How do you select a sunscreen?
With so many brands of sunscreen available, selecting the right
sunscreen can be difficult. These tips may help you in making your
selection:
- Dermatologists strongly recommend using a sunscreen
with an SPF 15 or greater year-round for all skin types. If you
are fair-skinned and sunburn easily, you may want to select a
sunscreen with a higher SPF to provide additional protection.
Using a cream, oil or lotion is a matter of personal choice, but
keep in mind that most oils do not contain sufficient amounts
of sunscreen and usually have an SPF of less than 2. All sunscreens
need to be reapplied, so follow the guidelines written on the
sunscreen bottle. Gel sunscreens tend to sweat off and, therefore,
need to be reapplied more frequently. Remember, expensive sunscreens
are not necessarily of better quality.
- Choose a "broad-spectrum" sunscreen that
protects against UVB and UVA radiation. PABA, or para-aminobenzoic
acid, was one of the original ultraviolet B (UVB) protecting ingredients
in sunscreens. However, some people's skin is sensitive to PABA,
and it also can cause staining of clothing. Today, PABA has been
refined and newer ingredients called PABA esters (such as glycerol
PABA, padimate A and padimate O) can be found in sunscreens. PABA
and PABA esters only protect against UVB radiation, the sun's
burning rays that are the primary cause of sunburn and skin cancer.
Also look for other UVB absorbers listed in the ingredients such
as salicylates and cinnamates.
You should look for a sunscreen that also protects
against ultraviolet A (UVA) radiation, those rays that penetrate
deeper into the skin and are the culprits in premature aging and
wrinkling of the skin. UVA-screening chemicals include oxybensone,
sulisobenzone and Parsol 1789, also called avobenzone. NOTE: The
SPF number on sunscreens only reflects the product's ability to
screen UVB rays. At present there is no FDA-approved rating system
that measures UVA protection levels.
Look for a sunscreen that is "waterproof"
or "water-resistant," especially if you participate in
outdoor physical activity.
Is there a difference between
"waterproof" and "water-resistant?"
How well the sunscreen stays on the skin after swimming, bathing
or perspiring is just as important as the SPF level. The FDA considers
a product "water-resistant" if it maintains its SPF level
after 40 minutes of water exposure. A product is considered "waterproof"
if it maintains its SPF level following 80 minutes of exposure to
water. If you participate in outdoor recreational activities including
swimming, you may want to choose a waterproof sunscreen.
What is the difference between
sunscreen and sunblock?
Sunscreens can be classified into two major types: chemical and
physical. Chemical sunscreens contain special ingredients that act
as filters and reduce ultraviolet radiation penetration to the skin.
These sunscreens often are colorless and maintain a thin visible
film on the skin. These sunscreens usually contain UVB absorbing
chemicals and more recently contain UVA absorbers as well.
Physical Sunscreens, most often referred to as sunblocks,
are products containing ingredients such a titanium dioxide and
zinc oxide which physically block ultraviolet radiation (UVR). Sunblocks
provide broad protection against both UVB and UVA light. They can
be cosmetically unacceptable to many people, because they are often
messy, visible and do not easily wash off. However, some new zinc
oxide products are available in brightly colored preparations which
are popular with young people. The amount of sun protection these
sunblocks provide, while potentially high, cannot be quantified
in the same manner as sunscreen SPFs. Physical sunscreen is recommended
for individuals who have unusual sensitivity to UVR. Most recently
on the sun protection scene is sun-protective clothing designed
to block UVA and UVB radiation. The effective SPF is greater that
30.
When should you use a sunscreen?
Sunscreens should be used daily if you are going to be in the sun
for more than 20 minutes. Most people will receive this amount of
sun exposure while performing routine activities. They can be applied
under makeup. There are many cosmetic products available today that
contain sunscreens for daily use because sun protection is the principal
means of preventing premature aging and skin cancer. Sunscreen used
on a regular basis actually allows some repair of damaged skin.
Because the sun's reflective powers are great - 17 percent on sand
and 80 percent on snow - don't reserve the use of these products
for only sunny summer days. Even on a cloudy day 80 percent of the
sun's ultraviolet rays pass through the clouds. Skiers beware, ultraviolet
radiation increases 4 percent for every 1,000-foot increase in altitude.How
much sunscreen should you use and how often should you apply it?
You should apply sunscreen to your dry skin 30 minutes BEFORE going
outdoors. Pay particular attention to your face, ears, hands and
arms. Apply sunscreen liberally using one ounce to completely cover
your body. Be careful to cover exposed areas, a missed spot could
mean a patchy, painful sunburn. Lips get sunburned too, so apply
a lip balm that contains sunscreen with SPF 15 or higher. Sunscreens
should be applied in the morning and reapplied after swimming or
perspiring heavily. Remember, waterproof sunscreen begins losing
effectiveness after 80 minutes in the water, so reapply sunscreen
before this time, especially if you have towel-dried for maximum
protection.
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