Wednesday, October 22, 2014
Pharmacy and Medications
Hi there, what is the highest SPF of sunscreen available today? Is it possible to make a sunscreen with as high SPF as we wish or is there any limitation?
SPF levels describe the amount of UVB protection offered by a sunscreen. Studies have shown that an SPF of 15 blocks 93% of UVB rays, an SPF of 30 blocks nearly 97%, and an SPF of 50 blocks about 98% of UVB rays.
Going much above 50 does not significantly increase the amount of protection. However, since virtually no one applies enough sunscreen, (you should apply a shot glass full at every application) the higher the SPF, the more likely you will get some protection from burning.
There are some companies that offer sunscreens of an SPF of 75 or 90, but how much more protection they provide is controversial. For that reason there is a cap of 50+ for SPFs in Europe and Australia. A proposal for the FDA to do the same in the US is on the table. Since we now know that in addition to being responsible for causing wrinkling, UVA rays found in sunlight also contribute to skin cancer development. That makes it very important that in addition to using an appropriate SPF for your type of skin and activity, you make sure your sunscreen also lists UVA protection.
Tatiana M Oberyszyn, PhD
Associate Professor of Pathology
Associate Professor of Molecular Virology, Immunology & Medical Genetics
College of Medicine
The Ohio State University