The News You Need to Know About Sunscreen


Millions of Americans are in the sun, and the unprotected exposure places and those who are not wearing the proper sunscreen are at risk for skin cancer. In our region of the country, this is very important as sun-safety is necessary to protect us against skin cancer, particularly squamous cell cancer. Sunscreen use can help prevent melanoma, which can be a fatal form of skin cancer. Sunscreen is also very important for children, fair-skinned individuals and those who have sensitivity to the sun for medical reasons.

There’s confusion about the amount of sunscreen to use, what sun protective factor or SPF to use, and how often to replace the sunscreen, if you are in and out of the water.

The SPF is determined by the amount of lotion or spray that prevents sunburn, tested at 2 milligrams per square centimeter of skin or about one-half square inch.

Unfortunately, most people apply only 20% to 50% of the amount needed to obtain the appropriate protection from the sun. To determine the amount of sunscreen needed to cover the entire body, a rule of thumb is to apply a shot glass full of sunscreen. Of course, the example of a shot glass is based on an average human. Obviously, the amount of sunscreen used will be based on body size and each person’s sensitivity to the sun. The shot glass rule has been recently modified into the teaspoon rule that suggests a half a teaspoon for each arm, each leg, the chest, the face and neck, which is the equivalent of six teaspoons or fluid ounce.

The SPF should be 50 or greater, especially if you are out in the sun when there is the highest ultraviolet radiation, which is between 10:00 AM and 2 PM. An SPF of 50 or greater blocks out 98% of the ultraviolet B rays, which are responsible for sun burning.

Reapplying sunscreen after an hour or two in the sun is also necessary for achieving the best SPF protection. If you are continuously in the water for over an hour, you will need to get out of the water and apply additional sunscreen.

By the way, diligent use of sunscreen can also slow or temporarily prevent the development of wrinkles, moles and sagging skin.

What’s the bottom line? Use enough sunscreen and massage it into the skin so there is no residual left on the skin. If you find you are still getting pink or red after an hour in the sun, you need to put more on. Finally, if you see any permanent discoloration of the skin, see your doctor or a dermatologist.

Dr. Neil Baum is a physician at Touro Infirmary. He can be reached at (504) 891-8454 or via his website,

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