UVA, UVB, SPF? What Does It All Mean?

Now that summer is here, let’s talk about protecting your skin. With so many sunscreen and sunblock products on the market, it’s often hard to know which ones work best for you and your skin.

Posted on | Jodi Sawyer, RN | Comments ()

Now that summer is here, let’s talk about protecting your skin.  With so many sunscreen and sunblock products on the market, it’s often hard to know which ones work best for you and your skin.

Let’s begin with sunscreen or sunblock – which one is better? The truth is that they are equally effective, they are just made up of different ingredients. Sunblock contains titanium dioxide and zinc oxide, which create a reflective, mirror-like shield that helps to deflect the suns damaging rays from your skin. Sunscreen, on the other hand, contains PABA, benzophenones, cinnamates and walicylates, which work more like a sponge in that they soak up or absorb the sun’s harmful rays.

It is important to use a sunscreen that blocks both UVA and UVB rays, but what is the difference between the two?  UVA rays are always present, no matter the weather or season and were once thought of as less damaging. However, we now know that these rays are very powerful and are one of the main causes of premature aging, sun spots and leathery skin.  UVA rays deeply penetrate the skin and can also penetrate clothing and glass.  UVB rays are not are strong as UVA rays, but they are the main cause of sunburns and skin cancers and thus are just as damaging, if not more damaging, than UVB rays.

To properly protect yourself against the sun’s harmful rays, you must wear sunscreen or sunblock that contains SPF.  SPF, or sun protection factor, is the measure of a product’s ability to screen or block the sun’s harmful rays. However, figuring out which SPF you should wear can be very confusing, especially with SPF numbers ranging from 2 to 100.

It would be natural to assume that SPF 100 would be twice as effective as a SPF 50.  However, this is not necessarily true.  According to the American Melanoma Foundation, “If you use a sunscreen with an SPF 15, you can be in the sun 15 times longer than you can without sunscreen before burning. However, consumers need to be aware that SPF protection does not increase proportionally with an increased SPF number.  While an SPF of 2 will absorb 50% of ultraviolet radiation, and SPF of 15 absorbs 93% and an SPF of 34 absorbs 97%.” Sunscreens and blocks that claim to be completely waterproof or sweatproof just add to the confusion of SPF numbers.  However, the one thing that typically holds true for all sunscreens and blocks is that it’s important to apply 30minutes before going in the sun and to reapply every two hours. 

Because of this SPF confusion, the FDA is mandating some changes regarding the labeling of all skin protection products. These changes were originally going to take effect on June 18, but an extension has been issued to December 17, 2012.  This extension was given by the FDA to give manufactures six more months to comply with their new regulations so that we don’t see a shortage of sunscreen and sunblock products, especially over the summer months. 

To help minimize the confusion, the FDA is mandating the following changes:

  • Sunscreen products that are not broad spectrum or that are broad spectrum with SPF values from 2 to14 will be labeled with a warning that reads: “Skin Cancer/Skin Aging Alert: Spending time in the sun increases your risk of skin cancer and early skin aging. This product has been shown only to help prevent sunburn, not skin cancer or early skin aging.”
  • Water resistance claims on the product's front label must tell how much time a user can expect to get the declared SPF level of protection while swimming or sweating, based on standard testing. Two times will be permitted on labels: 40 minutes or 80 minutes.
  • Manufacturers cannot make claims that sunscreens are “waterproof” or “sweatproof” or identify their products as sunblocks. Also, sunscreens cannot claim protection immediately on application (for example, “instant protection”) or protection for more than two hours without reapplication, unless they submit data and get approval from the FDA.
  • Any sunscreen with an SPF higher than 50 will have to be labeled SPF 50+.

The sun can be a wonderful thing, but it can also have many damaging effects that lead to wrinkles and health issues. Remember to apply sunscreen or sunblock 30 minutes before stepping out into the sun and reapply every two hours.   

Blog written by Jodi Sawyer, RN
Jodi Sawyer has worked as a registered nurse for over 14 years and was one of the first RNs in Southern California to work with...