We all love being in the sun, but no one wants to deal with sunburn after. People have long been familiar with sunscreen and SPF numbers, but UPF and sun protective clothing are still gaining traction. Understanding UPF (Ultraviolet Protection Factor) is the first step to make sure you’re well-protected from the sun whether you’re climbing mountains or just hanging out outside.
Sun protection is especially important in environments where the sun is hitting you from above and being reflected back at you – like when you’re on the water, on snow, on rock faces or in the desert. These are some of our favorite places to be, so we’ve prioritized UPF protection in our Merino wool clothing.
UPF vs. SPF: What's the Difference?
While both UPF and SPF measure sun protection, UPF is used for clothing and SPF for sunscreen. The UPF number indicates how much ultraviolet light passes through fabric in a lab test. SPF indicates how long sunscreen will protect your skin. When we talk about sun protection in our clothing, you’ll see UPF ratings. For both UPF and SPF, higher numbers mean greater protection.
Making Sense of UPF Numbers
To qualify as “UPF clothing,” a garment needs a UPF of at least 15. To earn the Skin Cancer Foundation’s seal of recommendation, a garment needs a minimum of 30 UPF. UPF 50+ is the most protective rating you’ll see.
|
UPF Rating |
Amount of UVB rays able to pass through |
|
15 |
7% |
|
30 |
3.3% |
|
50+ |
2% |
“The UPF number does not convey the effectiveness of UVA protection. This is usually not a problem because protection offered by clothing is naturally well balanced between UVA and UVB. A shirt that blocks most UVB rays will also block most UVA rays (Diffey 2012). In contrast, a high SPF sunscreen may filter UVB rays well, but that's no guarantee of good UVA protection.”
Our lightweight Solstice Sun Hoodies have a natural UPF of 35+ and they’re made specifically to be worn in the sun – they’re breathable and moisture-wicking, and you can trust them to protect your skin all day long.
Our ultralight Pursuit Hoodies have UPF 25. In general, thicker and darker fabrics are more sun protective, and our heavier base layers and hoodies are UPF 50+.
While numbers under UPF 15 can’t be qualified as UPF clothing, they still offer some sun/UPF protection. For daily use, you may find you’re adequately protected from the sun wearing regular long sleeve shirts and pants. A standard cotton shirt usually only provides a UPF of 5 or 10, which is also below this threshold.
The Truth About Sun Protective Clothing Treatments
Many clothing brands use chemical additives to enhance the UPF value of their clothing. These treatments lose their effectiveness over time, and you’ll often see these garments mention a number of washes they can take before protection dwindles.
Our approach at Ridge Merino is different. Our Merino wool clothing offers natural sun protection without using any chemical treatments. You’ll be protected from the sun and have natural fibers against your skin, which is good for you and good for the planet. Plus you don’t have to worry about the sun protection from Ridge Merino clothing diminishing over time. You’re protected as long as your garment isn’t full of holes or tears.
Sun Protection at Higher Altitudes
As you go up in elevation, the sun’s impact gets more intense because there’s less atmosphere to absorb the damaging rays. This means you need to be even more careful than you would be at lower elevations.
Thankfully altitude doesn’t affect a garment’s UPF rating. When you’re up high in the mountains and moving fast, wearing UPF clothing is much easier than reapplying sunscreen every couple of hours. All of our mountain athletes swear by sun hoodies.
Wetness and UPF
It’s worth noting that when fabrics get wet, they’re less sun protective. Our garments are UPF-tested when they're dry, so expect somewhat less protection when wet. Merino wool still does a pretty good job protecting you if you get caught in a quick rainstorm, and you should be totally fine if you're just sweating on a climb.
Sun-protective clothing is a must for anyone who spends significant time outdoors. Our Solstice Sun Hoodie is a reliable choice, free from chemical treatments and backed by testing both in the lab and in the wild. Check out our UPF sun protection collection. Don’t forget to pack sunscreen for any areas that are still exposed and a hat to protect your face and eyes.
Still not sold on UPF clothing? Here are more benefits it offers over sunscreen.
