UPF is the standard used to measure the effectiveness of sun protective fabrics. UPF stands for Ultraviolet Protection Factor and indicates how much of the sun’s UV radiation penetrates a fabric and reaches the skin. UPF is associated with fabric and you will see a UPF rating from 15-50 associated with products that claim that they are sun protective. A fabric with a rating of 50 will allow only 1/50th of the sun’s UV rays to pass through. This means the fabric will reduce your skin’s UV radiation exposure significantly because only 2 percent of the UV rays will get through. This also means that it blocks both UVA and UVB rays while SPF only takes the UVB rays into account. Currently, in the United States, the standards for UPF are voluntary. Check with your sun protective clothing company to see if they do independent testing on their fabrics to test their UPF claims.
SPF is a standard used to measure the effectiveness of sunscreen. SPF stands for Sun Protection Factor. It measures the amount of time it takes for sun-exposed skin to redden, while UPF measures the amount of UV radiation that penetrates a fabric and reaches the skin. Remember that SPF only accounts for UVB rays unless specifically stated as a broad spectrum sunscreen.
As you can see when you are trying to keep your skin protected it is important to know the different rating systems. Many skin-care experts believe clothing shields skin more effectively from UV light than sunscreen. Many of us often apply sunscreen lotions too thinly, giving our skin less protection than the sunscreen’s available SPF rating, and we neglect to reapply it as directed by the specific sunscreen that we use.
To receive The Skin Cancer Foundation’s Seal of Recommendation, sun-protective fabrics must have a minimum UPF of 30. They consider a UPF rating of 30-49 to offer very good protection and 50+ excellent protection. All of our Performance Shirts are rated UPF 50+, with protection that will never wash out.