Understanding SPF


SPF.  We are bombarded by this three letter acronym on a daily basis.  SPF, what exactly is it really?!?

The formula used in determining the wavelengths of the sun’s rays from the sun to earth.

ultraviolet-critical-wavelength-sunscreen-protectionSPF stands for, Sun Protection Factor.  It is a formulation that has been derived by scientists to understand the amount of time our skin will be protected against certain wavelengths of the sun’s UVC, UVB and UVA rays.  Last year, the FDA changed the number on the SPF, stating that companies could no longer sell products with an SPF of 35 or higher.  This change was made because consumers were purchasing SPF with 70+, 80+, even 100+ SPF sunscreens and realized people were still getting burnt and damaging their skin.  The FDA found that consumers thought that because they were applying a high content of an SPF on their skin they did not need to reapply and this caused misuse by the consumers.  They then have found that the SPF of 35 was not high enough and so they changed the SPF again and now no product can obtain an SPF over their number factor of 50+.


SPF-Sun-Protection-Factor-Chart-GuideHow does the number factor work?  Say it takes your skin 10 minutes to burn when exposed to the sun.  If you use an SPF of 30, multiply the 10 minutes X the 30 (SPF number) and you total 300 minutes.  Take the 300 and divide it by 60 (the amount of minutes in an hour) and the new number now becomes 5.  This means you are able to have your skin exposed to the sun for 5 hours wearing an SPF 30 on your skin.  The chart on the right is a good guideline of taking your Fitzpatrick skin type and quantifying the SPF number and the amount of time your skin is protected.

beach-volleyballSPF can be ineffective if your body sweats a lot, participating in outdoor activities that make you perspire, swimming and coming in and out of the water and/or having contact with the skin by rubbing the product with SPF in it off.  It is important to reapply when you see your skin becoming red or you have been active to make sure the SPF can provide the best protection possible.



The sun protection factor has been formulated to prevent dangers that the sun can cause, such as: skin cancer, aging and wrinkling.  Use it daily even if you’re not going to be playing in the sun, the sun’s rays are very strong and can penetrate through windows and even can touch your skin on cloudy days.  Refer back to the SPF chart for your skin type at any time if you need to know which SPF number your skin needs.