Solar protection - Effect of selected fabric and use characteristics on ultraviolet transmission

Clothing is worn in single- and multiple-layer arrangements and during use subjected to conditions such as extension and wetting. This study investigated how selected variables affected transmission of ultraviolet radiation (UVR) through fabrics and whether these variables interacted to modify transmission. Using a spectrophotometer the effect of i) fabric type (two knitted, two woven), color (black and white), wetness (dry, damp, wet), and extension (relaxed, extended (10 x 10%, 10 x 20%)), and ii) fabric type and layering (1, 2, 3 layers) of white fabrics, on UVR (290-400 nm), UVA (315-400 nm), UVB (290-31.5 nm), and ultraviolet protection factor (UPF) rating was investigated. Differences among variables were identified using univariate and repeated measures ANOVA, and interactions among variables identified and described. Selecting dark colors, limiting extension and layering fabric were shown to be effective ways of increasing UV protection and UPF by decreasing transmittance. However, the effect of color, extension and layering varied among fabric types and modified UVA and UVB transmittance differently.