Sunscreen SPF What Does It Mean?

Dear Dr. Dave and Dr. Dee,

I was at the beach with a group of friends and someone suggested that I use an SPF 8 sunscreen instead of what I was using (SPF 15, what my mom makes me wear). My friend stated that a lower SPF would help me tan quicker. Is that true and what does SPF mean anyway?

Signed,

Too pale

Signed,

Too pale,

SPF stands for Sun Protection Factor. The minimum SPF recommended for outdoor sun exposure is 15. For example, a person that normally burns in 10 minutes when out in the sun without protection, could stay out 15 times longer (150 minutes) and not burn with a sunscreen SPF of 15 (American Academy of Dermatology, 2009). However, depending on the intensity of the heat, sunburns could occur in a much shorter time. In addition, sunscreen should be reapplied often, especially after swimming or sweating, and applied over all exposed areas of the body. Tips on using sunscreen properly can be found in the letter, "Skin Cancer Prevention" below.

Even if wearing sunscreen, given the skin cancer risks and skin aging involved with overexposure to the sun, it's best to limit sun exposure between 10am and 4pm, seek shade, wear a wide-brimmed hat and sunglasses.

For more information about sunscreen, see the American Academy of Dermatology, "Facts About Sunscreens" at

http://www.aad.org/media/background/factsheets/fact_sunscreen.htm