What You Need to Know About Sunscreen and Protection from the Sun

Contact: Renette Wardlow, human development specialist

Tel: (417) 581-3558

E-mail: wardlowr@missouri.edu

OZARK, Mo. -- Whether it’s “fun in the sun” or “work in the sun,” protection from ultraviolet rays of the sun is important for everyone – both children and adults.

“Many of us use it but the selections in the aisle of the store can be confusing. It's hard to decide which SPF to use and whether you need protection against UVA, UVB or both,” said Renette Wardlow, a human development specialist with University of Missouri Extension.

UVA and UVB are types of ultraviolet radiation. Humans need protection against ultraviolet radiation because it contributes to conditions such a premature skin aging, eye damage and skin cancer. These types of ultraviolet 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 than UVB rays. UVA rays penetrate the skin more deeply than UVB and 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. We now know that UVA can contribute to and may even initiate the development of skin cancers,” said Wardlow.

UVA is the ray that makes humans 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. Humans are most exposed to UVB rays from April to October and between the hours of 10 a.m. and 4 p.m.

UVB rays do not penetrate glass. UVA rays can and do penetrate glass in homes and in cars causing damage while we are unaware it is happening.

“That is why it is a good idea to even use sunscreen while on road trips,” said Wardlow.

SPF stands for Sun Protection Factor. Experts recommend that you use a SPF of at least 15.

“A SPF of 15 means it will take 15 times longer for skin to redden than if you did not use it at all. The SPF refers to UVB protection only,” said Wardlow.

To assure you are getting protection from UVA as well, Wardlow says to look for one of these ingredients: stabilized a avobenzone, ecamsule (Mexoryl), oxybenzone, titanium dioxide or zinc oxide. 

“One thing to remember when using sunscreens is that they do tend to wash off, such as when you perspire heavily. Labels are now carrying information on the products resistance to washing off. When looking for protection from the sun, remember to look for the SPF number and the products resistance to washing off,” said Wardlow.