The Impact of Routine Laundering on Ultraviolet Protection Factor (UPF) Values for Commercially Available Sun-Protective Clothing.

Background Ultraviolet (UV) radiation has potentially harmful effects on the skin. Sunscreen products have historically focused on blocking UV-B radiation to prevent sunburns while efforts to block UV-A radiation have been lacking. UV protective clothing, rated by ultraviolet protection factor (UPF) values, has gained popularity as an alternative form of UV protection, offering a physical barrier against UV rays. However, concerns arise regarding the disclosure and sustainability of UV-protective textiles, as companies often do not disclose the methods used to achieve UV protection. The addition of chemical sunscreen additives to textiles raises questions about their potential release during laundering and their impact on sustained UV protection and environmental health. Further research is needed to understand the risks and benefits of these practices. Methods Seven garments from commercially available sun-protective brand names claiming UV protection were tested for UPF values. The garments were washed separately using cold water in commercially available detergent in cold water followed by drying on a low setting. UPF measurements were obtained at baseline and at intervals of 10 wash cycles until 50 wash cycles were completed. Results Two brands (Brands A and D) experienced a significant decrease in UPF value (70% to 78%) by the completion of 50 washes. Brand A disclosed the use of a nano-zinc additive in their garments while Brand D did not disclose the means of achieving UV protection. In comparison, five brands (Brands B, C, E, F, G) maintained relatively stable UPF values throughout the 50 washes. The comparison between Brand A and Brand G, who disclosed their UV protection methods, showed that Brand A gradually decreased in UPF value throughout the washes while Brand G remained stable. Conclusion The findings suggest that textile compositions with UV finishes may lose their UPF effectiveness during laundering by loss of the finish used over time or the textile integrity could be affected. This raises questions about the necessity of adding these UV finishes if there are fabrics that can maintain their UPF values without them.