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What you need to know about sunscreen

Tammy Roberts, Nutrition and Health Education Specialist, Bates County, University of Missouri Extension


woman holding sunscreenThis time of year, sunscreen is one of the most important things on the shopping list. In the past, choosing sunscreen has been difficult because of the confusion over whether you needed UVA or UVB protection. The Food and Drug Administration has a new ruling that takes the guesswork out of purchasing sunscreen.


Starting this summer (2012), sunscreens labeled “Broad Spectrum” must protect against both UVA and UVB rays. In the past, products carrying the “Broad Spectrum” label did not necessarily protect against UVA rays.


UVA and UVB are types of ultraviolet radiation. We need protection against ultraviolet radiation because it contributes to conditions such as premature skin aging, eye damage and skin cancer. This radiation can also suppress the immune system making it difficult to fight these conditions. The U.S. Department of Health and Human Services and the World Health Organization recognize UV as a proven carcinogen.


UVA rays are 30 to 50 times more prevalent and penetrate the skin more deeply than UVB rays. This contributes to skin aging. We used to believe that aging was the worst damage that UVA could do. We now know that UVA rays damage skin cells in the basal layer of the epidermis where most skin cancers occur. UVA can contribute to and may even initiate the development of skin cancers. UVA is the ray that makes us tan. Tanning in the sun or in a salon can cause damage over time which can lead to skin cancer.


UVB rays are the ones that cause sunburn. It has long been known that UVB rays play an important role in the development of skin cancer. UVB rays vary in intensity depending on the season, location and time of day. We are most exposed to UVB rays from April to October and between the hours of 10:00 a.m. and 4:00 p.m.


SPF stands for Sun Protection Factor. Experts recommend that you use an SPF of at least 15. An SPF of 15 means that it will take 15 times longer for skin to redden than if you did not use it at all. The higher the SPF level on a broad-spectrum sunscreen, the better it will protect against both UVA and UVB.


Enjoy the summer, but make sure you are protected against the sun's harmful rays. Be sure to re-apply sunscreen after sweating and after swimming.


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Last Updated 07/16/2012