Have you ever wondered how sun protection clothing came into existence? To be fair people have been covering their bodies from the sun for decades, but the term “sun protection” and a defined level of protection is relatively new.
Sun protection clothing became popular in Australia first, and other nations followed. And it is in Australia where the first standard for sun protection clothing was established in 1996 by the federal agency ARPANSA, (Australian Radiation Protection and Nuclear Safety Agency) who regulate and lab-test UV protective fabrics.
British standards were set not long after in 1998 by the NRPB (National Radiological Protection Board). The USA organisation ASTM (American Standards and Testing Methods) set their standards in 2001.
Although testing on fabrics originally focused on swimwear, UV testing is now carried out on many outerwear clothing too. Fabrics tested now are given a UPF (Ultraviolet Protection Factor). E.g., the fabric used in Bohn Swimwear has a UPF of 50+
Before UPF (Sun Protection Factor) standards were in place, SPF (Sun Protection Factor) ratings were used for clothing. It was changed because SPF is a rating that is used for skin applications, it measures how much longer a person’s skin takes to redden when the application was applied. UPF is a clearer rating for a fabrics ability to block UV rays and offer protection.
A UPF rating of 50 indicates the fabric of a garment will allow only 1/50th (roughly 2%) of available UV radiation to pass through it. A garment rated UPF 25 permits roughly 4% (1/25th) UV transmission.
The higher the number, the better the protection the fabric offers. Any fabric that allows less than 2% UV transmission is labelled UPF 50+. This is the rating the Bohn Swimwear fabric
The ARPANSA states that garments made with fabrics rated below UPF 15 cannot be marketed as offering UPF protection. For example an everyday plain white t-shirt will normally have a UPF rating between 5 -8 which means it can let up to 20% of the UV radiation to reach your skin.
So be careful out there in the sun.