What is the Difference Between UPF and SPF?

You’re probably familiar with the SPF (sun protection factor) ratings found on sunscreen, but what is UPF clothing? Did you know clothing has its own UV protection rating system? You’ll see this rating, known as an ultraviolet protection factor, or UPF for short, when buying sun protective clothing or bamboo apparel. But what exactly do SPF and UPF ratings measure, and how do they compare?

Before we dive into the differences, it’s important to understand the reason we are protecting our skin at all. The ultraviolet (UV) rays from the sun are harmful, especially during long periods of exposure. Unprotected exposure to UV rays damages the skin, and cause over 90% of all nonmelanoma skin cancers.

Broad-Spectrum

Sunscreen labeled as “broad-spectrum” blocks both UVA (long wave ultraviolet A) and UVB (short wave ultraviolet B), each of which damages the skin. Any sunscreen not labeled broad-spectrum is generally designed simply to protect from short wave UVB rays to avoid a burn, but will not block harmful UVA rays. Whenever possible, always choose broad-spectrum protection.

SPF

SPF stands for “sun protection factor” and is a relative measure of a sunscreen’s effectiveness in protecting your skin from UV rays. A higher SPF rating means that it will block a higher percentage of UV rays, but nothing is 100%. The number generally correlates to the multiple of time in which you can avoid a burn. So if you would normally burn in 10 minutes, and properly applied an SPF 30 sunscreen, it would take you about 300 (10 x 30) minutes to burn (assuming you are constantly covered and re-applying).

UPF

So we know what Broad-Spectrum and SPF are, but what is UPF clothing? UPF (ultraviolet protection factor), on the other hand, is specific to sun protective fabrics. UV radiation can penetrate clothing and as with SPF, the higher the value, the more protection you receive. The specific UPF rating of the garment indicates the amount of the sun’s UV radiation it allows through. For example, a UPF 50 shirt only allows 1/50th or 2% of the UV rays through, a UPF 30 shirt only allows 1/30th or about 3% through, and so on. Plus, unlike sunscreen, UPF apparel always blocks both UVA and UVB rays and is always broad-spectrum.

UPF ratings can be difficult to identify, as they’re rarely marked in any product details. That is, unless the garment is specifically designed for UV protection. The average cotton t-shirt's UPF value is 5 or less, and determining the exact UPF rating requires costly, time-consuming testing. Also, while it’s required that apparel show its country of origin and fabric content, there is no requirement for a manufacturer to provide the product’s UPF rating. This leads to many companies taking the cheap and easy route—not listing it at all. So in general, if an article of clothing does not have a UPF value listed (and it’s not thick like denim or heavy fleece), it’s safest to assume it does not provide significant UV protection.

SPF & UPF, In Summary:

• SPF rates the UV protection effectiveness of sunscreens
• UPF rates the UV protection effectiveness of protective fabrics
• UPF is always broad-spectrum, SPF is not
• Fabrics with UPF provide constant coverage, SPF and sunscreens need regular re-application to maintain protection
• When choosing UPF apparel, look for ratings of UPF 30 or greater for very good UV protection

Rayward Apparel focuses exclusively on UPF apparel, specializing in sun protective shirts that are as comfortable as they are protective. Shop Rayward Apparel today!

Our vision sees through the sun’s glare and extends far beyond clothing. We go beyond clothing with our dedication to supporting the fight against skin cancer, donating 5% of online sales to the Melanoma Research Alliance to further research and treatment of skin cancer. Learn more about how Rayward gives back.

Source: Skin Cancer Foundation, Skincancer.org