Understanding SPF

What does SPF mean anyways?


Many of us slather it on when we are at the pool or lake, but do you really understand what SPF and its corresponding numbers mean?

The sun emits two different types of rays- UVA and UVB. Think of UVA as the rays that damage our skin causing early signs of aging and a major cause of skin cancer. They can mutate the pigmentation functions of cells to produce more or less pigment resulting in spots that are very hard and possibly impossible to correct. They also increase the breakdown of collagen and elastin that keep our skin firm and wrinkle free. UVB rays are those that cause burns to the skin, which over time can cause skin cancer. Melanoma, a form of deadly skin cancer, is one of the top diagnosed cancers for those aged 20-39. Which means those long days out at the pool should also come with regular sunblock application.

SPF stands for Sun Protection Factor or the amount of time one can be exposed to the sun's rays before burning. For example, SPF 30 will protect the skin from 95% of UVB rays and SPF 50 about 98%. Nothing except 100% zinc oxide can block 100% of UV rays, and that would leave you with a thick white goopy later of cream, gross. So when it comes to the number of your SPF, the higher the number the better the protection for two hours of wear.

SPF also comes in two forms- sunscreens (chemical) and sunblocks (physical). For the most part, sunscreens or chemical sunscreens are formulations that only absorb some of the sun's rays, allowing some of those nasty disease- causing rays through. Sunscreens primarily focus on absorbing UVB rays, only some formulation give protection from both UV rays. Sunblocks are physical blocks that offer protection from both UVA and UVB rays to ensure healthy skin when you are outdoors. Even on cloudy days, when planning on being outside for at least 20 minutes make sure you pack the sunblock and reapply regularly. Even sunblocks labeled as 'water-resistant' break down over time and should be reapplied at least every two hours for full protection.

PCA Skin offers a variety of sunblocks that are recognized and recommended by the Skin Cancer Foundation. Their sunblocks don't just have top active ingredients zinc oxide, avobenzone, and octinoxate. In addition they have ingredients that aid in eliminating damaged cells, suppressing the formation of sunburn cells, and even pigment reducers! Great double duty for those with limited time in the mornings.


Whatever SPF you choose, make sure to reapply to combat the main source of prematurely aging skin!