The Environmental Protection Agency (EPA) has a clearly written website titled “The Sun, UV and You.”. It addresses the risks from overexposure to the sun’s ultraviolet rays and how to protect yourself from UV radiation. However, the most useful information is found at the American Cancer Society (ACS) website where you can take a quiz that rates your “Sun-Safety IQ”.

At the risk of giving away the answer to question 4…

Remember, the sun protective factor (SPF) describes how long a sunscreen product protects your skin if applied correctly. Protection is based on the SPF combined with your sensitivity to the sun.

For example, fair-skinned people begin to burn in about 15 minutes on a sunny day. Wearing an SPF 15 sunscreen prevents sunburn for about 3 hours, 45 minutes. Multiply how many minutes you can be exposed to the sun until you start to burn by the SPF number (eg, 15 minutes exposure x 15 SPF = 225, or 3 hours and 45 minutes).

In the same person, SPF 30 sunscreen should last 450 minutes (15 minutes exposure x 30 SPF = 450), or 7 hours and 30 minutes. Wait a minute! Apparently, the calculation only provides the most general guideline, because despite the answer, ACS and EPA recommend reapplying sunscreen every 2 hours.

The quiz also covers the importance of a “base tan,” the protective value of a T-shirt, and other practical considerations.

7/11/06 03:58 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.