In Europe sunscreens are classified and regulated as cosmetics and their efficacy is evaluated under standardized condition in accordance with the International Standard ISO24444:2010 Cosmetics –Sun protection test methods –In vivo determination of the sun protection factor (SPF) test method.
SPF is determined by the ratio of UV energy required to produce a minimal erythemal dose (MED) in protected skin (standardized application thickness of 2 mg/cm2) to unprotected skin and is a measure for the UVB-protection effectiveness of a sunscreen.
Positioning of irradiation unit.
