The appreciation of the potential hazard of ionizing radiation led to the setting up of national, and later, international commissions for the defining of standards of protection for the occupationally exposed worker in the use of ionizing radiation. However, in the last twenty years, with the large scale development of nuclear energy, the need for adequate protection against ionizing radiation has become even more important. This code of practice for the use of ionizing radiations in secondary schools was compiled and recommended by the Occupational Health Committee of the National Health and Medical Research Council of Australia. The publication comprises eight outline sections--(1) Introduction, (2) Modes of Irradiation, (3) General Rules, (4) Control of Sources, (5) Storage and Labeling, (6) Handling of Sources, (7) Disposal of Sources, and (8) The Degree of the Hazard. (KK)