Slip versus Slop: A Head-to-Head Comparison of UV-Protective Clothing to Sunscreen.

Ultraviolet radiation (UVR) exposure is the most important modifiable risk factor for skin cancer development. Although sunscreen and sun-protective clothing are essential tools to minimize UVR exposure, few studies have compared the two modalities head-to-head. This study evaluates the UV-protective capacity of four modern, sun-protective textiles and two broad-spectrum, organic sunscreens ( SPF 30 and 50). Sun Protection Factor ( SPF ), Ultraviolet Protection Factor ( UPF ), Critical Wavelength (CW), and % UVA - and % UVB-blocking were measured for each fabric. UPF , CW, % UVA - and % UVB-blocking were measured for each sunscreen at 2 mg/cm 2 (recommended areal density) and 1 mg/cm 2 (simulating real-world consumer application). The four textiles provided superior UVR protection when compared to the two sunscreens tested. All fabrics blocked erythemogenic UVR better than the sunscreens, as measured by SPF , UPF , and % UVB-blocking. Each fabric was superior to the sunscreens in blocking full-spectrum UVR, as measured by CW and % UVA -blocking. Our data demonstrate the limitations of sunscreen and UV-protective clothing labeling and suggest the combination of SPF or UPF with % UVA -blocking may provide more suitable measures for broad-spectrum protection. While sunscreen remains an important photoprotective modality (especially for sites where clothing is impractical), these data suggest that clothing should be considered the cornerstone of UV protection.