Appendix 3-Shipping rules___ 24 1. Interstate Commerce Commission regulations_ 24 27 SAFE HANDLING OF I. General Considerations 1. Scope of This Handbook Prior to World War II the use of radioisotopes was essentially limited to a few locations having access to cyclotron-induced activities. The addition of pile-induced activities, either as fission products or as special irradiations, has changed the magnitude of the related protection problems. Widespread laboratory and industrial use of radioistopes is foreseen. This involves the protection of scientists and technicians in one case, of industrial employees in the other, and of the public in both cases. This handbook cannot give detailed recommendations, necessary and sufficient for all cases. It is, therefore, planned to give the general recommendations suitable for typical laboratory or small industrial operations. In all cases management specifically assumes the responsibility for the proper selection and maintenance of the standards necessary for safe operation. The small laboratory, handling low levels of radioactivity, may modify or omit some of the following recommendations. A periodic review of such modifications by a competent radiation protection authority may be desirable. The large laboratories and industries will require more detailed control. The employment of full-time personnel qualified in radiation protection is then desirable, and should be mandatory where the staff working regularly with radioactive material exceeds 25. Specific attention is directed to the usage of “shall” and "should" throughout the recommendations. The former is used in a mandatory sense. The latter applies to those recommendations that may be redundant at low activity levels, optional at intermediate levels, and essential at high levels. 2. Available Radioisotopes Table 1 lists the radioisotopes of generally greatest interest, and indicates the order of magnitude of the amounts normally available. A knowledge of the sites of deposition and elimination routes is a partial requirement for the hazard evaluation and tests for each particular isotope. Severe radiation hazard is associated with those isotopes that have unfavorable combination of long half-life, high uptake, deposition in small organs or in bone, and low elimination rates. a Calcium absorption and excretion is dependent on blood calcium level. b Iron absorption from the gut is influenced by the level of iron present in the blood and liver. Once iron enters into the metabolism of the animal, the excretion rate for that iron is very low. As: Retention in all tissue is very low. Do. Bone: M....do... High.. Bone: M. Urine. High.. Bone: M. Urine do... Same. Same. Same.. Same.. Same... Same... 5 Bone: H. d Sr: Absorption and deposition (5 to 80 percent in bone) vary with age and existing Ca level. • Doses in excess of 0.1 gm give a low retention. f H, L, and M indicate high, low, or moderate percentage of deposit out of total amount absorbed. Indicates chiefly dependent on compound. h "Same" implies that the property under "Inhalation" or "Parenteral" is the same as The ditto marks the corresponding property listed under "Ingestion" for each isotope. "do" or "Do" apply to the vertical columns. TABLE 2. Hazard from absorption into the body Selected radioisotopes grouped according to relative radiotoxicity, with the amounts considered as low, intermediate, or high level, in laboratory practice. Effective radiotoxicity is obtained from a weighting of the following factors: Half-life. Energy and character of radiations. Degree of selective localization in the body. Quantities involved and modes of handling in typical experi ments. The slant boundaries between levels indicate border-line zones, and emphasize that there is no sharp transition between the levels and the associated protection techniques. The principal gamma-emitters are indicated by asterisk (e. g., *Na24). The above level system does not apply to the hazards of ex ternal irradiation. Table 2 shows the common isotopes subdivided into three groups, according to relative radiotoxicity following accidental intake into the body. The diagram attempts to define the ranges of low level, intermediate level, and high level activity used in the laboratory, with respect to intake hazards. When the hazard is confined to that from external radiation, low, intermediate, and high levels are normally considered in terms of the emitted gamma radiation. These levels are not defined in this report, because the required |