Archive
Autumn 2001, Vol. 9 No. 3
H.K. Dermatol. Venereol. Bull. (2001) 9, 100-108
Review Article
Sunscreens: Is Looking at Sun Protection Factor Enough?
TY Ho
Abstract
As mounting evidence points to the photocarcinogenicity and the photoaging potential of chronic ultraviolet A (UVA) exposure, broad-spectrum sunscreens that are effective against both ultraviolet B (UVB) and UVA radiation are obviously preferred. Older chemical filters are not effective against the longer UVA. Several chemical filters have been developed recently to provide invisible protection for the UVA spectrum. The sun protection factor (SPF) can only indicate the level of protection against UVB, but not UVA. There is not yet any widely accepted method to measure UVA protection.