It’s the summer. The sun is out in full force. Folks are going to the beach, the pool, walking to the car as fast as possible to get in the AC.

Recently, WFMY News 2’s Chad Silber snapped a picture in a store of different sunscreen options and sent it to reporter, Hope Ford. The picture shows three cans; one says SPF 70, one says SPF 30 and one says SPF 100.

So, it made us wonder.

QUESTION: Does a high SPF really mean more protection from the sun?

PROCESS: To verify, we pulled a study from the Skin Cancer Foundation.

Dermatologists said high SPFs give people a false sense of security. You would think, an SPF 100 means I’m 100 percent blocked from the sun and I can stay out longer. But, that’s not the case.

SPF means sun protection factor. SPF 30, for example, let’s in 1/30 of sun rays. If you’re not one for fractions, here’s a percentage breakdown.

SPF 30 = 1/30 or 3%

SPF 50= 1/50 or 2%

SPF 100= 1/100 or 1%

So, to recap (and simplify) SPF 30 let’s in 3 percent of sun rays, SPF 50 lets in 2 percent of sun rays and SPF 100 lets in 1 percent of sun rays.

It’s a very small difference, even though the number on the actual bottle shows a bigger gap.

And, you must apply enough for the sunscreen to work in the first place. Dermatologists recommend using at least a palm size amount to cover exposed parts of the body. Sunscreen takes 15 to 30 minutes to absorb. Sweat and water decrease the product’s effectiveness, meaning it must be reapplied often, no matter how high the SPF.

If you’re using a spray sunscreen, its recommended to spray each body part for at least six seconds to get the same results as a lotion.

One more thing to consider. If the bottle says “broad-spectrum”, that means it’s protecting you from UVB rays (which cause sun burns) and UVA rays (which cause sun damage, like aging and skin cancer.) If the bottle does not have a broad-spectrum label, the product is only protecting you from sun burns.

So, we can verify, with only a one percent difference in protection, high SPFs don’t mean much.


Skin Cancer Foundation

Dr. Steven Wang, Director of Dermatologic Surgery and Dermatology, Memorial Sloan-Kettering Cancer Center at Basking Ridge, NJ


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