Progress in commercialization of the irradiation process, greater international trade in irradiated food, differing regulations relating to use of the technology in many countries, and consumer demand for clear labeling of irradiated food highlighted the need for tests that could be applied to the food itself. Scientists have had to focus on identifying and isolating the minute changes caused in the component food molecules by the process. A number of investigators have reviewed the changes occurring in food after irradiation, detecting and measuring the effects of irradiation. The Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture organised a coordinated program on analytical detection methods in irradiation treatment of food (ADMIT) which promoted cooperation in this area and sponsored collaborative testing of some of the most promising methods.