a woman looking over her shoulder wearing sun blocking clothing

UPF, The Next SPF?

I am sorry to have to do this, but we have another acronym to deal with in the world of skincare and sun protection. Just when you thought that you had them all memorized, let’s welcome UPF into our lingo. Yes, UPF (Ultraviolet Protection Factor) the latest in a series of important abbreviations with which we should become familiar. UPF is important because it relates to something we all deal with every day: our clothing. Specifically, UPF is a rating given to clothing in how well they protect our bodies against dangerous ultraviolet (UV) sun rays.

I learned clothing is important

One thing that I have tried to do for years after my initial melanoma diagnosis is to cover my skin with my clothing when going outside for extended periods. I have always thought that wearing a long-sleeved shirt was great protection from harmful UV rays. Well, it turns that this is only partly true and can vary based on a boatload of factors. UV rated clothing is especially important for sun-sensitive people, children, people at higher elevations, in equatorial regions, or people near snow or water (with their reflective sun rays). Even people on certain types of medications are more susceptible to UV rays.

UPF ratings

UPF ratings on clothing are similar to SPF (Sun Protection Factor) ratings for sunscreen. It is quite simple actually, the higher the rating, the higher the protection. Ratings under 20 offer what is considered “good” protection. Ratings from 25-35 offer “very good” protection with “excellent” ratings of 40 or more. Any fabric rated 25 will allow 1/25 (4%) of available UV radiation to pass through it. A fabric rated 50 will allow only 2% of available UV radiation. Fabrics under 15 are not considered UV-protective. A typical cotton shirt is rated at 5.

What fabrics provide protection?

UPF specifications are assigned to garments and are related to these factors.

  • Construction-Tighter, denser, and thicker fabrics allow less UV radiation to pass through to the skin.
  • Color-Darker colors (and more vibrant) absorb UV rays.
  • Treatments-Dyes and chemicals may be added to provide more UV protection.
  • Type of Fiber-Polyester and nylon have the most UV protection.

Other considerations are important to note. The wetness, wear and stretch (or shrinkage) of fabrics affect their UPF. Washing fabrics with UPF-enhancing chemicals will tend to lessen their ability to block out UV rays. Inherently UV disruptive fabrics will tend to lose their effectiveness over time as they wear. A good rule of thumb seems to be, the darker and thicker the fabric, the better it will be at protecting one’s skin from the sun.

It's important

So, there you go. UPF is important. I know now that simply putting on a white cotton t-shirt is better than going shirtless with regard to sun protection, but it affords less protection than I had originally thought. Wearing sunscreen under my t-shirt is a good strategy to deal with those sneaky UV rays. Yet, another acronym to consider along the melanoma highway.

By providing your email address, you are agreeing to our privacy policy.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The SkinCancer.net team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

Join the conversation

Please read our rules before commenting.

Community Poll

Have you taken our In America survey yet?