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Sunscreens Explained

Prevention of sun damage is a critical part of good skin care. Regular use of sunscreen will prevent or delay a variety of skin conditions including some skin cancers, premature wrinkling of the skin, and uneven pigmentation. A sunscreen with at least an SPF 30 and with UVA and UVB coverage is recommended. When swimming, choose a water-resistant formulation. Reapply sunscreen every 4 hours while outdoors or every 2 hours if swimming or sweating.

Bullfrog brand sun block is both non-greasy and water-resistant and comes in both gel and spray applications. It is also available in combination with an insect repellant if needed.

What Are Sunscreens?
Sunscreens are chemical agents that help prevent the sun's ultraviolet (UV) radiation from reaching the skin. Two types of ultraviolet radiation, UVA and UVB, damage the skin and increase your risk of skin cancer. UVB is the chief culprit behind sunburn, while UVA rays, which penetrate the skin more deeply, are associated with wrinkling, leathering, sagging, and other effects of photoaging. They also exacerbate the carcinogenic effects of UVB rays, and increasingly are being seen as a cause of skin cancer on their own. Sunscreens vary in their ability to protect against UVA and UVB.

What Is SPF?
Most sunscreens with an SPF of 15 or higher do an excellent job of protecting against UVB. SPF - or Sun Protection Factor - is a measure of a sunscreen's ability to prevent UVB from damaging the skin. Here's how it works: If it takes 20 minutes for your unprotected skin to start turning red, using an SPF 15 sunscreen theoretically prevents reddening 15 times longer - about five hours.

Another way to look at it is in terms of percentages: SPF 15 blocks approximately 93 percent of all incoming UVB rays. SPF 30 blocks 97 percent; and SPF 50 blocks 99 percent. They may seem like negligible differences, but if you are light-sensitive, or have a history of skin cancer, those extra percentages will make a difference. And as you can see, no sunscreen can block all UV rays.

But there are problems with the SPF model: First, no sunscreen, regardless of strength, should be expected to stay effective longer than two hours without reapplication. Second, "reddening" of the skin is a reaction to UVB rays alone and tells you little about what UVA damage you may be getting. Plenty of damage can be done without the red flag of sunburn being raised.

Who Should Use Sunscreen?
Anyone over the age of six months should use a sunscreen daily. Even those who work inside are exposed to ultraviolet radiation for brief periods throughout the day. Also, UVA is not blocked by most windows.

Children under the age of six months should not be exposed to the sun. Shade and protective clothing are the best ways to protect infants from the sun.

What Type of Sunscreen Should I Use?
The answer depends on how much sun exposure you're anticipating. In all cases we recommend a broad-spectrum sunscreen offering protection against both UVA and UVB rays.

Many after-shave lotions and moisturizers have a sunscreen (usually SPF 15 or greater) already in them, and this is sufficient for everyday activities with a few minutes here and there in the sun. However, if you work outside or spend a lot of time outdoors, you need stronger, water-resistant, beachwear-type sunscreen that holds together on your skin. The "water resistant" and "very water resistant" types are also good for hot days or while playing sports, because they're less likely to drip into your eyes. However, these sunscreens may not be as good for everyday wear. They are stickier, don't go as well with makeup, and need to be reapplied every two hours.

Many of the sunscreens available in the US today combine several different active chemical sunscreen ingredients in order to provide broad-spectrum protection. Usually, at least three active ingredients are called for. These generally include PABA derivatives, salicylates, and/or cinnamates (octylmethoxycinnamate and cinoxate) for UVB absorption; benzophenones (such as oxybenzone and sulisobenzone) for shorter-wavelength UVA protection; and avobenzone (Parsol 1789), ecamsule (Mexoryl), titanium dioxide, or zinc oxide for the remaining UVA spectrum.

How much sunscreen should I use and how often should I put it on?
To ensure that you get the full SPF of a sunscreen, you need to apply 1 oz - about a shot glass full. Studies show that most people apply only half to a quarter of that amount, which means the actual SPF they have on their body is lower than advertised. During a long day at the beach, one person should use around one half to one quarter of an 8 oz. bottle. Sunscreens should be applied 30 minutes before sun exposure to allow the ingredients to fully bind to the skin. Reapplication of sunscreen is just as important as putting it on in the first place, so reapply the same amount every two hours. Sunscreens should be reapplied immediately after swimming, toweling off, or sweating a great deal.

Common myths
Wearing sunscreen can cause vitamin D deficiency.
There is some controversy regarding this issue, but few dermatologists believe (and no studies have shown) that sunscreens cause vitamin D deficiency. Also, vitamin D is available in dietary supplements and foods such as salmon and eggs, as well as enriched milk and orange juice.

If it's cold or cloudy outside, you don't need sunscreen.
This is not true. Up to 40 percent of the sun's ultraviolet radiation reaches the earth on a completely cloudy day. This misperception often leads to the most serious sunburns, because people spend all day outdoors with no protection from the sun.

80 percent of your sun exposure comes as a child, so it's too late to do anything now.
It appears that this universally promoted idea was based largely on a misinterpretation. A recent multi-center study showed that we get less than 25 percent of our total sun exposure by age 18. In fact, it is men over the age of 40 who spend the most time outdoors, and get the highest annual doses of UV rays. And since adult Americans are living longer and spending more leisure time outdoors, preventing ongoing skin damage will continue to be an important part of a healthy lifestyle.

Buy a high-quality product with an SPF of 15 or higher; check its ingredients to make sure it offers broad-spectrum protection; and decide whether it works better for everyday incidental use or extended outdoor use. Finally, look for The Skin Cancer Foundation's Seal of Recommendation, which guarantees that a sunscreen product meets the highest standards for safety and effectiveness. Once you choose the right sunscreen, use it the right way. But remember, you should not rely on sunscreen alone to protect your skin against UV rays. By following our guidelines, you can lower your risk of developing skin cancer, while helping your skin look younger, longer.


Sun protection at any age is important to prevent the short-term as well as long-term damaging effects of sunlight. Sunscreen plays a major part and should be used in conjunction with other sun-safety steps for optimal sun protection.

A single overexposure to sunlight can result in painful, red, sunburned skin. A bad burn when young can have serious consequences such as skin cancer later in life. Long-term overexposure can cause skin cancer, wrinkles, freckles, age spots, dilated blood vessels, and changes in the texture of the skin that make skin look older.

The Cause of Sun Damage
The sun produces both visible and invisible rays. The invisible rays, known as ultraviolet A (UVA) and ultraviolet B (UVB), cause most of the problems, including suntan, sunburn, and sun damage. There is no "safe" ultraviolet (UV) light, and there is no such thing as a safe tan.

Sun Protection
Sun protection helps prevent skin damage, wrinkles, and reduces the risk of developing skin cancer. Newer broad-spectrum sunscreens contain products to block both UVA and UVB rays. Sunscreen should be reapplied at least every two hours to work. The American Academy of Dermatology recommends that you seek shade when possible. Avoid sunbathing, wear a wide-brimmed hat, sunglasses and protective clothing. A typical white tee shirt has an SPF of 3. Colorless dyes are available as laundry products which increase the SPF of fabrics to an SPF of 30. If you must be in the sun, use a broad-spectrum sunscreen with a sun protection factor (SPF) of at least 15, even on cloudy days. Sunscreens, however, are not perfect. Because some ultraviolet light may still get through sunscreens, they should not be used as a way of prolonging sun exposure.

Sunscreens - How They Work
Sunscreens work by absorbing, reflecting, or scattering the sun's rays on the skin. They are available in many forms, including ointments, creams, gels, lotions, sprays, and wax sticks. All are labeled with SPF numbers. The higher the SPF, the greater the protection from sunburn caused mostly by UVB rays, but this does not increase the length of time for sun exposure. Broad-spectrum sunscreens protect against both UVA and UVB rays. They do a better job of protecting skin from other effects of the sun including photo damage, photodermatitis, and rashes from the sun.

Types of Sunscreens
Sunscreens that block UVB rays are composed of some or all of the following chemicals: padimate O, homosalate, octyl methoxycinnamate, benzophenone, octyl salicylate, phenylbenzimidazole sulfonic acid, and octocrylene. Broad-spectrum sunscreens add oxybenzone or avobenzone (Parsol 1789) to block UVA rays. Mexoryl is a chemical that blocks UVA; its broad-spectrum characteristics allow sunscreens to be made with very high SPF factors. Physical sunscreens/blocks or chemical-free sunscreens contain titanium dioxide and/or zinc oxide, which reflect UVA and UVB and are especially useful for people allergic to chemical sunscreens.

Proper Use of Sunscreen
Sunscreen should be applied one half hour before going outdoors. Even water-resistant sunscreens should be reapplied often, about every two hours or after swimming, drying off or perspiring. Sunscreen should be applied generously and evenly so as not to miss any areas of sun-exposed skin. It should be kept out of the eyes, and UV light-blocking sunglasses should be worn.

Tips for Sun Protection
Sun exposure is the most preventable risk factor in the development of skin cancer. You can have fun in the sun and Be Sun SmartSM. Here's how to do it:

  • Generously apply sunscreen to all exposed skin. The sunscreen should have an SPF of at least 15 and be broad - spectrum. Re-apply every two hours, even on cloudy days, and after swimming or perspiring.
  • Wear protective clothing such as a long-sleeved shirt, pants, a wide-brimmed hat and sunglasses, when possible.
  • Seek shade when appropriate, remembering that the sun's rays are strongest between 10 a.m. and 4 p.m.
  • Use extra caution near water, snow, and sand as they reflect the damaging rays of the sun, which can increase your chance of sunburn.
  • Protect children from sun exposure by applying sunscreen.
  • Get vitamin D safely through a healthy diet that includes vitamin supplements. Do not seek the sun.
  • Avoid tanning beds. UV light from the sun and tanning beds causes skin cancer and wrinkling. If you want to look like you have been in the sun, consider using a self-tanning product which does not expose you to UV light. Continue to use sunscreen daily.
  • Check your birthday suit on your birthday. If you notice anything on your skin that is changing, growing, or bleeding, see a dermatologist. Skin cancer is very treatable when caught early.

Self-tanning lotions and sprays are a safe alternative to tanning. They contain dihydroxyacetone which interacts with proteins in the skin to produce an orange/tan color that does not wash off. However, the color of self-tanners only has an SPF of 4. This is not enough protection; therefore, sunscreen with a SPF of at least 15 must be used and reapplied every two hours.

Additional Information About Sun Protection
The greatest sun damage occurs between 10 a.m. and 4 p.m. when the sun's rays are strongest. Even on cloudy days, when it does not feel hot, or when under trees, sunscreen and other sun-protective measures should be used because sunburn and sun damage to the skin can occur.

Beach umbrellas and other kinds of shade are a good idea, but they do not provide full protection. UV rays can still bounce off sand, water, and porch decks; sunscreen usage is a must. Remember, UV rays are invisible.

Most clothing absorbs or reflects UV rays, but lighter colored and loose-knit fabrics as well as wet clothes that cling to your skin do not offer much protection. The tighter the weave, the more sun protection the clothing offers.

Artificial UV light from tanning beds causes the same types of problems, photodamage, and cancers that natural sunlight can cause. The use of indoor tanning for non-medical purposes should be avoided.

Sun protection also is important in the winter. Snow reflects up to 80 percent of the sun's rays, causing sunburn and damage to uncovered skin. Winter sports in the mountains increase the risk of sun damage because there is less atmosphere to block the sun's rays.

Benefits of Sunscreen


SCHAUMBURG, ILL (March 31, 2006) - Today, the American Academy of Dermatology (Academy) reaffirmed its long-standing position that sunscreen is beneficial when used regularly and properly and in conjunction with wearing protective clothing and seeking shade. The Academy urges people to Be Sun SmartSM when outdoors by protecting themselves from the harmful rays of the sun.

"Scientific evidence supports the beneficial effects of proper sunscreen usage," said dermatologist Stephen P. Stone, M.D., president of the Academy. "While it is an important tool in the fight against skin cancer, sunscreen alone does not protect you enough. People shouldn't feel they can stay in the sun for extended periods of time just because they are wearing sunscreen."

More than 1 million new cases of skin cancer are diagnosed each year. Of these cases, more than 111,900 are melanoma, a cancer that claims nearly 8,000 lives annually.

"While health issues are complex and involve multiple factors, we know that ultraviolet (UV) rays are the primary cause of skin cancer and the solution is to avoid excessive exposure to the sun and other forms of UV radiation," stated Dr. Stone. "In fact, the United States Department of Health & Human Services declared UV radiation from the sun and artificial sources as a carcinogen in 2002."

If you are going to be in the sun for more than 20 minutes, the Academy recommends that you generously apply sunscreen to all exposed skin using a Sun Protection Factor (SPF) of at least 15 that provides broad-spectrum protection from both ultraviolet A (UVA) and ultraviolet B (UVB) rays. It is important to re-apply every two hours, even on cloudy days, and after swimming or sweating.

Dr. Stone noted that the average person requires one ounce of sunscreen, enough to fill a shot glass, to adequately cover the exposed areas of the body. He also emphasized that sunscreen should be applied at least 15-30 minutes before going outdoors in order to allow it to be completely absorbed into the skin.

The Academy urges people to Be Sun SmartSM by wearing sunscreen and:

  • Wearing protective clothing, such as a long-sleeved shirt, pants, a wide-brimmed hat and sunglasses, where possible.
  • Seeking shade when appropriate, remembering that the sun's rays are strongest between 10 a.m. and 4 p.m.
  • Using extra caution near water, snow and sand as they reflect the damaging rays of the sun which can increase your chance of sunburn.
  • Protecting children from sun exposure by applying sunscreen.
  • Getting vitamin D safely through a healthy diet that includes vitamin supplements. Don't seek the sun.
  • Avoiding tanning beds. Ultraviolet light from the sun and tanning beds causes skin cancer and wrinkling. If you want to look like you've been in the sun, consider using a sunless self-tanning product, but continue to use sunscreen with it.
Advanced Dermatology
8940 Darrow Road
Twinsburg, Ohio 44087


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BullFrog is available in the Twinsburg office and a variety of recommended brands are available on-line.

Bull Frog
The best sunscreens for the face is a gel. Gels do not clog your pores. Experts swear by Bull Frog Superblock Sun Block. Its long-lasting lotion protects even the fairest of skin types.

Extra tip:
Sunscreen isn't only for the face. We read in O magazine that dermatologists report seeing too many women with hands, necks and chests that looked 20 years older than their faces. These women were diligent to keep their faces out of the sun but forgot to protect their hands, necks and chests as well.


Sunscreen Information


Smart Sun Safety

BullFrog is available in the Twinsburg office and a variety of recommended brands are available on-line.

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