Every summer, shelves fill up with sunscreen. Thanks to diligent parents and public health preaching, SPF has become a staple in most people’s outdoor routines, especially during the summer. And it should be: More people are diagnosed with skin cancer each year in the U.S. than all other cancers combined, according to the Skin Cancer Foundation.
But another, more fashionable form of sun protection is gaining popularity in the U.S. UPF, or Ultraviolet Protection Factor, clothing is clothing that protects you from the sun. It’s like SPF but in clothing form and it looks just like regular clothing but is made with specific fabrics and sewn in specific ways to help block harmful rays from tanning or burning the skin. UPF is very different from SPF, or Sun Protection Factor, what you’re used to seeing on a sunscreen bottle.
“A UPF rating is given to clothing and other fabrics that protect you from the sun, while an SPF rating is only used for sunscreens and cosmetics containing sunscreen,” Adele D. Haimovic, a dermatologist and spokesperson for The Skin Cancer Foundation, told The Daily Beast. “UPF measures the effectiveness of sun protective fabrics. The UPF indicates what fraction of the sun’s ultraviolet rays can penetrate a piece of fabric. For example, a shirt with a UPF rating of 50 allows just 1/50th of the sun’s UV rays to reach the skin.”
UV, or ultraviolet, rays are made up of wavelengths classified as UVA, UVB or UVC, according to the Skin Cancer Foundation. UVA is the longest wavelength, followed by UVB and UVC. Most UVC rays are too short to penetrate the atmosphere and thus, damage your skin, which is why you’ve most likely heard of UVA and UVB. Both UVA and UVB rays can cause skin cancers, and sun protections vary in which rays they protect you from.
SPF is used to rate a sunscreen’s ability to protect against just UVB rays, where UPF measures both UVA and UVB protection.
“SPF indicates how long you can stay in the sun before your skin reddens,” Haimovic said. “Theoretically, if it would take 20 minutes for your unprotected skin to turn red in the sun, using an SPF 15 sunscreen would prevent reddening 15 times longer. But no sunscreen should be expected to remain effective for more than two hours without reapplication.”
All clothing, whether it’s labeled as UPF specific or not, has some protection against the sun. The average white cotton T-shirt only has a UPF of about 5, though, where UPF clothing made by brands like Patagonia have a 50+ UPF protection, the standard globally. In the U.S., UPF clothing is regulated by the Federal Trade Commission, while sunscreen is regulated by the Food and Drug Administration.
But just like SPF can wash off and wear off, so can UPF.
“Most of the companies that you look into suggest UPF can last 30 to 40 washes, so if you’re using these regularly, I would say a year or two,” Mary Stevenson, a dermatologist at New York University's Langone Health, said about how long this clothing’s protection power lasts.
Because of this, she said that backing up with sunscreen was the safest option: “I’m also a proponent of applying sunscreen and then putting UPF clothing over the sunscreen so that you get the extra benefit of it, not using one in lieu of the other.”
And some UPF clothing could offer more protection than others. Haimovic said that the tightness of the fabric weave and the fabric color can change effectiveness. A tightly-woven piece with smaller holes between the thread, like denim, will offer more protection than one with an open weave, like a crocheted shawl. Thicker and darker fabrics are more protective than thin, light fabrics. A bleached cotton offers little protection, whereas a black corduroy would block more UV radiation.
Courtney Dunlop, a former beauty editor who owns a skincare boutique called Good Skin Day, started wearing UPF swim shirts about 10 years ago.
“I loved it so much it snowballed into wearing regular UPF clothing,” she told The Daily Beast. “Unlike sunscreen, it doesn't degrade in the sun, and you can't wipe or sweat it off. That is very helpful when you are at the beach, or even just walking around outside.”
Dunlop said her UPF clothing habit doesn’t do much for her fashion choices.
“It definitely hinders your style a lot. I'm not running around in cute tank tops and sleeveless dresses,” she said.
And fellow UPF fan Kate Winick agreed. Winick told The Daily Beast that she currently turns to Cover Swim, which is made in the U.S., for UPF swim protection but that she’s eager to book a trip to Australia for for UPF options.
There are some U.S. companies creating UPF clothing, though. Patagonia, for one, is well-known for its UPF options. Matt Dwyer, Senior Director of Materials Innovation at Patagonia, told The Daily Beast that the brand’s peak UPF sales are in the spring product season. Patagonia also third-party tests all of its UPF clothing, as do brands like Coolibar, a Minnesota-based UPF clothing company that’s gained traction for its more fashion-forward selection.
“We conduct an initial UV transmittance test, we launder each garment 40 times, expose it to 100 fading units of simulated sunlight, and then conduct a second UV transmittance test. The tests measure transmittance across both the UVA and UVB spectrum,” Coolibar CEO Kendra Reichenau told The Daily Beast. “Our garment ratings are based on the lower result of the initial ‘brand new’ test and the second life cycle’ test. Most fabrics lose some level of UV protection with wear, so most fabrics are rated based on their second test.”
Stevenson said to look into the quality of the UPF clothing you might buy, confirm that the brand you’re buying from actually tests the products and has a UPF of 30 or 40 or above.
“I use 40 as a general guideline if you’re going to invest the time and the money,” she said.
And don’t forget the sunscreen. Haimovic said to remember that no single sun protection method is foolproof. A complete sun protection strategy should include covering up with clothing, hats, and sunglasses in addition to seeking shade and daily sunscreen use. UPF might sound cool, but it can only take you so far.