Health Topic Categories

- Skin -

May 30th, 2012

What You Need to Know about Sun Protection

What is the best protection from sun damage?

Simply put, the best protection from sun damage is sun avoidance. Avoid the sun from 10 AM until 4 PM when the sun is most intense. Avoid sunlight during this time even if the sunlight is coming through a glass window. Seek shade. Wear protective clothing.


What is protective clothing?

Cover as much skin as possible. Long sleeves in summer are fine. Hats with a 4-inch brim all around protect the scalp, face, ears, and neck. The easier it is to see through clothing, the less effective it is as sun protection, so don’t be afraid to hold it up to the light before buying it. Clothing loses most of its sun protection when it becomes wet. Tightness of the weave is much more important than the thickness of the cloth. Dark colors protect better than light colors. Finally, some clothes actually have an SPF rating, and the FDA lists these as medical devices.


Are sunscreens helpful?

Besides offering some protection from simple sunburn, regular use of sunscreen reduces the occurrence of skin cancers, especially squamous cell carcinoma, as well as other ski disorders such as actinic keratoses and solar elastosis.


What do numbers such as SPF-30 mean on sunscreen?

An SPF-30 product supplies enough protection so that after 30 minutes of exposure to sunlight, the skin sustains only the amount of damage as it would after 1 minute of exposure without sunscreen. Similarly, SPF-15 confers 15 times the resistance of unprotected skin.


What does it mean when sunscreens bear the label “water resistant” and “very water resistant”?

“Water resistant” means that the screen maintains its SPF level after 40 minutes of water immersion. “Very water resistant” means that a product maintains its SPF level after 80 minutes of water immersion.
What do “full spectrum” or “broad spectrum” mean on the sunscreen label?
A full or broad-spectrum sunscreen protects against the longer wavelength ultraviolet A (UV-A) and the shorter wavelength ultraviolet B (UV-B). Sunscreens without this designation are usually effective primarily in the UV-B range.


Are there different types of sunscreen?

Sunscreens fall into two general groups.


Chemical absorbers absorb the energy of shorter wavelength UV light, converting it to safer longer wavelength UV light, which is far less damaging after it penetrates to the skin. The absorbed energy is used to drive chemical change in the components of the sunscreen. When avobenzone is a component of chemical absorbers, it extends their protection to the UV-A range.


Physical blockers don’t transmit light and so prevent contact of sunlight with the skin. Consequently they are effective in both UV-A and UV-B ranges. Physical blockers typically contain as ingredients either titanium dioxide or zinc oxide.


Isn’t zinc oxide the white stuff the lifeguards wore on their noses when I was a kid and my parents took me to the beach?

Yes, but today’s sunscreens contain these oxides as microparticles that are much more acceptable esthetically.


Don’t we need sunlight to produce vitamin D?

Sunscreens still permit the penetration of sufficient sunlight to sustain normal vitamin D levels. Older individuals can supplement this with 1000 International Units of vitamin D daily.


Is it true that you can get sunburned on a cloudy day?

Yes, even substantial cloud cover may block only 20% of ultraviolet rays.


Do I need to reapply sunscreen if I haven’t gone into the water?

Yes, reapply every few hours. Even if the sunscreen hasn’t washed away by water or perspiration, the active chemicals in the sunscreen have been dissipated by their conversion of more damaging shorter-wavelength UV rays into less damaging longer-wavelength UV rays.


So the Erie County Medical Society hopes that you will take precautions when you enjoy the outdoors. Taking these precautions will help you enjoy healthier and younger-looking skin in addition to reducing your risk of skin cancer.


For more information visit

Pennsylvania Academy of Dermatology and Dermatologic Surgery

Skin Cancer Foundation

Thomas Falasca, DO

Lessons from the COVID Pandemic

2021-07-14 17:10:53

Lessons to Learn from the COVID Pandemic ...

Herd Immunity against COVID with Dr. Jeff McGovern

2021-07-14 17:10:53

Dr. Jeff McGovern on Herd Immunity to COVID ...

Bergamo, Italy: Army Removing Bodies of COVID Victims

2021-07-14 17:10:53

RUPTLY - News that Expands Views ...

Differences among COVID face coverings

2021-07-14 17:10:53

Dr. Tom Falasca discusses reduced COVID protection from some face coverings ...