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Sunscreen

1. Who needs to use sunscreen?

In a word: everyone! The FDA (Food and Drug Administration) and the American Academy of Dermatology recognize six skin categories:

The American Academy of Dermatology suggests that, regardless of skin type, a sunscreen with an SPF (Sun Protection Factor) of at least 15 should be used year-round.

2. When should a sunscreen be used?

Sunscreens should be used every day if you are going to be in the sun for more than 20 minutes. 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. Sunscreens used on a regular basis actually allow some repair of damaged skin.

However, because sun exposure is responsible for vitamin D production in the skin, elderly persons who use sunscreen regularly may require vitamin D supplements.

The sun's reflective powers are great - 17 percent on sand and 80 percent on snow. Don't reserve the use of these products only for sunny summer days. Even on a cloudy day, 80 percent of the sun's ultraviolet rays pass through the clouds.

3. How do I choose a sunscreen?

There are so many types of sunscreen, that selecting the right one can be quite confusing. Is it better to use an oil or cream? Should a sunscreen be water resistant or not? And must it contain PABA to be effective?

PABA, or para-aminobenzoic acid, was the original compound which was the basic ingredient of sunscreens. However, it stained clothes. Today's PABA has been refined and the newer ingredient called PABA esters include glycerol PABA, padimate A (pentyl dimethyl PABA) and padimate O (octyl dimethyl PABA). These rarely stain clothing as the original PABA once did. Some people are sensitive to PABA and its esters and should seek products that contain other chemicals such as benzophenones (oxybenzone), cinnamates (octylmethyl cinnamate and cinoxate) and salicylates.

Sunscreens are available in many forms including ointments, creams, gels, lotions and wax sticks. The type of sunscreen you choose is a matter of personal choice. Keep in minds that most tanning oils do not contain sufficient amounts of sunscreens and usually have an SPF of less than 2.

All sunscreens need to be reapplied. Water resistant sunscreen needs to be reapplied about every 2 hours or immediately after swimming or strenuous activities. Gels need to be reapplied frequently (as they sweat off and wash off most easily), but may be preferable for acne-prone people.

4. What is an SPF?

SPF stands for Sun Protection Factor. Sunscreens are rated or classified by the strength of their SPF. The SPF numbers on the packaging can range from as low as 2 to as high as 60. These numbers refer to the product's ability to screen or block out the sun's burning rays.

The sunscreen SPF rating is calculated by comparing the amount of time needed to produce a sunburn on protected skin to the amount of time needed to cause a sunburn on the unprotected skin. For example, if a sunscreen is rated SPF 2 and a fair-skinned person who would normally turn red after ten minutes of exposure in the sun uses it, it would take twenty minutes of exposure for the skin to turn red. A sunscreen with an SPF of 15 would allow that person to multiply that initial burning time by 15, which means it would take 15 times longer to burn, or 150 minutes.

5. What is the difference between UVA and UVB light wavelengths?

Sunlight consists of two types of harmful rays - UVA rays and UVB rays. The UVB rays are the sun's burning rays (which are blocked by window glass) and are the primary cause of sunburn and skin cancer. UVA rays (which pass through window glass) penetrate deeper into the dermis, or base layer of the skin. They also contribute to skin burning and skin cancer. Both UVA and UVB rays can cause suppression of the immune system which helps to protect you against the development and spread of skin cancer.

Since PABA, PABA esters, and cinnamates only protect against UVB light, check a sunscreen for products that also screen UVA rays, like benzophenones, oxybenzone, sulisobenzone, titanium dioxide, zinc oxide, and Parsol 1789 ( butyl methoydibenzoylmethane, also called avobenzone). These are called "broad-spectrum" sunscreens.

6. How much sunscreen should be used, and how often should it be applied?

Sunscreens should be applied to dry skin 15 to 30 minutes BEFORE going outdoors. When applying sunscreen, pay particular attention to the face, hands and arms, and coat the skin liberally. One ounce, enough to fill a shot glass, is considered the amount needed to cover the exposed areas of the body properly. Be careful to cover exposed areas completely - a missed spot could mean a patchy, painful sunburn. Don't forget that lips get sunburned too, so apply a lip balm that contains sunscreen, preferably with an SPF of 15 or higher.

Sunscreens should be applied in the morning and reapplied after swimming or perspiring heavily. Even so-called water resistant sunscreens may lose their effectiveness after 80 minutes in the water. Sunscreens rub off as well as wash off, so if you've towel-dried reapply waterproof sunscreen for continued protection. Don't forget that sun exposure occurs all the time, even while you're taking a short walk on a cloudy day.

Source : The American Academy of Dermatology