This high SPF technically provides you with 30+ times your natural protection. This means if you usually begin to show a response to sun exposure in 15 minutes, SPF 30+ will allow you to stay up to eight hours, under normal sun conditions, before seeing a response to sun exposure. The damage to the skin, after 15 minutes of sun exposure, should therefore be limited to at least 1/30 of the total damage that would normally occur on unprotected skin.
a selective skin care catalog
