(1997; 132 pages) [French] [Spanish]
Ultraviolet radiation-blocking agents (sunscreens)
Sunscreens protect the skin by either absorbing or reflecting ultraviolet radiation. Their efficacy in the ultraviolet B (290-320 nm) range is described as the SPF (sun protection factor), which is the ratio of the minimal ultraviolet dose required to produce erythema in skin protected by the sunscreen to the dose required without protection. Sunscreens rated for protection against ultraviolet A (320-400 nm) are termed broad-spectrum blocks.