 It was not until 1925 that the establishment of international radiation protection standards was discussed at the first International Congress of Radiology (ICR).The second ICR was held in Stockholm in 1928 and ICRU proposed the adoption of the roentgen unit; and the ‘International X-ray and Radium Protection Committee’ (IXRPC) was formed.Rolf Sievert was named Chairman, but a driving force was George Kaye of the British National Physical Laboratory.