Radiometric Quantities and Units Used in Photobiology and Photochemistry: Recommendations of the Commission Internationale de l’Eclairage (International Commission on Illumination)

To characterize photobiological and photochemical phenomena, standardized terms and units are required. Without a uniform set of descriptors, much of the scientific value of publications can be lost. Attempting to achieve an international consensus for a common language has always been difficult, but now with truly international scientific publications, it is all the more important. As photobiology and photochemistry both represent the fusion of several scientific disciplines, it is not surprising that the physical terms used to describe exposures and dosimetric concepts can vary from author to author. There are, however, international organizations that were established to minimize the confusion produced by poor or inconsistent technical terminology. This note is to review the standardized terms and provide a background on how such terms are developed, with the hope that all readers will attempt to follow the standardized terminology.