Journal Scan / Research · February 20, 2018

Broad-Spectrum Ultraviolet Protection of Clothing

Journal of the American Academy of Dermatology

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In this proof-of-concept study, the authors examined the UVA protection afforded by various dry clothing garments, including regular clothing fabrics (t-shirts, jeans), UV protective fabrics (athletic shirts, bathing suits), and commercially available sunscreens. All of the tested clothing garments exhibited broad-spectrum UV protection, which was highest for nylon bathing suits, denim jeans, and dark grey cotton shirts. All clothing garments tested also exhibited greater broad-spectrum UV protection than the sunscreens tested, apart from avobenzone.
These results show that clothing garments appear to provide better protection against UVA than most sunscreens, highlighting that dermatologists should be emphasizing the use of sun-protective clothing as first-line sun protection.
– Jeffrey F. Scott, MD

Abstract

Although ultraviolet B is a well known carcinogen, 32 recent evidence suggests that ultraviolet A (UVA) also contributes to skin cancer risk. To promote protection against UVA, the FDA standardized labeling and effectiveness testing for over-the-counter sunscreens in 2011; while maintaining the in vivo testing for evaluating UVB protection, this criterion added an in vitro measurement for UVA protection. Originally suggested by Diffey et al, the test calculates the wavelength at which the integral of the UV spectral absorbance curve reaches 90% of the total integral from 290 to 400 nm. A critical wavelength (CW) minimum of 370 nm defines broad spectrum coverage.