About 170 staff members from different European Commission departments subject to individual monitoring provided by the contracting authority are occupationally exposed to ionising radiation in the course of their work. The employer shall arrange for precautions and radiation monitoring appropriate to the risks associated with the work involving external exposure to ionising radiation as well as doses due to potential intakes of radioactive substances. The contracting authority has established a system for systematic monitoring, recording and reporting of individual radiation exposures.The individual radiation monitoring comprises also the annual detection of possible internal exposure due to intakes of radioactive substances with the Whole-Body Counter (‘routine’ monitoring) as well as ad-hoc detection of possible intakes (‘special’ monitoring).Radiation measurements in vivo with subsequent assessment of doses due to intakes of radioactive substances are subject of this call for tender.