Updated: Jul 7, 2018
As an outdoor enthusiast and horseback riding instructor, I spend a lot of time outdoors, especially during the summer months, and have come to rely on a few wardrobe staples to protect my skin from excessive sun exposure (in addition to sunscreen): a wide-brimmed hat, sunglasses, and several UPF-rated lightweight hiking shirts, like this one from Columbia Sportswear (men's version here).
What is a UPF rating?
In the past several years, many apparel manufacturers have started making clothing using fabrics that have been evaluated for effectiveness in blocking ultraviolet rays. The ultraviolet protection factor, or UPF, is determined by how effectively a garment protects skin from UVA and UBA rays emitted from the sun. This is quantified and translated to a numerical rating.
The UPF rating of a textile varies depending on the type of fabric, its weight, color, and construction of the garment. Fabrics made of tightly woven fibers provide more protection than loosely-woven fabrics.
How high of a rating means adequate sun protection? A garment with a UPF rating of 50 will allow just 1/50th of the sun’s UV radiation to reach your skin, which is excellent sun protection. A thin white cotton t-shirt, for instance, only provides a UPF of around 5. A minimum of UPF 30 is recommended for effective sun protection by the Skin Cancer Foundation.
Does a UPF rating mean a garment is treated for extra sun protection? Does this mean that only clothing labeled with UPF ratings will protect against the sun's harmful rays? Not necessarily. Thick, dense fabrics like corduroy and denim, for instance, offer excellent sun protection--but don't offer the same ventilation and cooling effects of a lightweight, long-sleeved, polyester sun shirt.
Remember, when it comes to sun protection, coverage is key. A UPF 50-rated tank top isn't going to protect your arms or chest from sun exposure. For more tips on preventing excessive sun exposure, check out my post on demystifying sun protection.